Editing Infant mortality (section)

== Causes ==
Causes of infant mortality, or direct causes of death, differ from contributions to the IMR, as contributing factors raise the risk of death, but do not directly cause death.<ref>{{Cite web |title=What causes infant mortality? |url=https://www.nichd.nih.gov/health/topics/infant-mortality/topicinfo/Pages/causes.aspx |access-date=2017-03-07 |website=www.nichd.nih.gov}}</ref> Environmental and social barriers that prevent access to basic medical resources contribute to an increased infant mortality rate, 86% of infant deaths are caused by [[infections]], [[premature births]], complications during delivery, perinatal [[asphyxia]], and birth injuries. Many of these common causes are preventable with low-cost measures.<ref name="Andrews" /> While 99% of infant deaths occur in developing countries, the greatest percentage reduction in infant mortality occurs in countries that already have low rates of infant mortality.<ref name="Andrews" /><ref name="Bishai">{{Cite journal |vauthors=Bishai D, Opuni M, Poon A |date=March 2007 |title=Does the level of infant mortality affect the rate of decline? Time series data from 21 countries |journal=Economics and Human Biology |volume=5 |issue=1 |pages=74–81 |doi=10.1016/j.ehb.2006.10.003 |pmid=17141591}}</ref>  In the United States, a primary source of infant mortality risk is infant birth weight, with lower birth weights increasing the risk;<ref>{{Cite journal |vauthors=Saugstad LF |date=September 1981 |title=Weight of all births and infant mortality |journal=Journal of Epidemiology and Community Health |volume=35 |issue=3 |pages=185–191 |doi=10.1136/jech.35.3.185 |pmc=1052154 |pmid=7199074}}</ref> the causes of low birth weight include socioeconomic, psychological, behavioral, and environmental factors.<ref name="Osel2008">{{Cite SSRN |title=Being (Born) Black in America: Perceived Discrimination & African-American Infant Mortality |year=2008 |ssrn=2173553 |vauthors=Osel JD}}</ref>

=== Main causes ===
There are  three main leading causes of infant mortality: conditions related to [[preterm birth]], [[birth defect|congenital anomalies]], and [[SIDS]] (sudden infant death syndrome).<ref name="dollfus-1990">{{Cite journal |last1=Dollfus |first1=C. |last2=Patetta |first2=M. |last3=Siegel |first3=E. |last4=Cross |first4=A. W. |date=August 1990 |title=Infant mortality: a practical approach to the analysis of the leading causes of death and risk factors |url=https://pubmed.ncbi.nlm.nih.gov/2371093/ |journal=Pediatrics |volume=86 |issue=2 |pages=176–183 |doi=10.1542/peds.86.2.176 |issn=0031-4005 |pmid=2371093 |s2cid=42744378}}</ref> In North Carolina between 1980 and 1984, 37.5% of infant deaths were due to prematurity, congenital anomalies accounted for 17.4% and SIDS accounted for 12.9%.<ref name="dollfus-1990" />

==== Premature birth ====
{{Main|Preterm birth}}
Premature, or [[preterm birth]] (PTB), is defined as birth before a [[gestational age]] of 37 weeks, as opposed to full term birth at 40 weeks. This can be further sub-divided in various ways, one being: "mild preterm (32–36 weeks), very preterm (28–31 weeks) and extremely preterm (<28 weeks)".<ref name="Moutquin-2003">{{Cite journal |vauthors=Moutquin JM |date=April 2003 |title=Classification and heterogeneity of preterm birth |journal=BJOG |volume=110 |issue=Suppl 20 |pages=30–3 |doi=10.1046/j.1471-0528.2003.00021.x |pmid=12763108 |s2cid=33268768 |doi-access=free}}</ref>  A lower gestational age increases the risk of infant mortality.<ref name="harrison-2016">{{Cite journal |vauthors=Harrison MS, Goldenberg RL |date=April 2016 |title=Global burden of prematurity |journal=Seminars in Fetal & Neonatal Medicine |volume=21 |issue=2 |pages=74–9 |doi=10.1016/j.siny.2015.12.007 |pmid=26740166}}</ref>

Between 1990 and 2010 prematurity was the second leading cause of worldwide mortality for neonates and children under the age of five.<ref name="Blencowe" /> The overall PTB mortality rate in 2010 was 11.1% (15 million deaths) worldwide and was highest in low to middle-income countries in sub-Saharan Africa and south Asia (60% of all PTBs), compared with high-income countries in Europe or the United States.<ref name="Blencowe">{{Cite journal |display-authors=6 |vauthors=Blencowe H, Cousens S, Oestergaard MZ, Chou D, Moller AB, Narwal R, Adler A, Vera Garcia C, Rohde S, Say L, Lawn JE |date=June 2012 |title=National, regional, and worldwide estimates of preterm birth rates in the year 2010 with time trends since 1990 for selected countries: a systematic analysis and implications |url=https://researchonline.lshtm.ac.uk/id/eprint/40396/1/1-s2.0-S0140673612608204-main.pdf__tid%3D6e9a5226-c455-11e5-8722-00000aacb362%26acdnat%3D1453830871_1bfa5cad3ce2895d33a963f1f360c67a |journal=Lancet |volume=379 |issue=9832 |pages=2162–72 |doi=10.1016/s0140-6736(12)60820-4 |pmid=22682464 |s2cid=253520}}</ref>{{Failed verification|date=July 2023}} Low-income countries also have limited resources to care for the needs of preterm infants, which increases the risk of infant mortality. The survival rate in these countries for infants born before 28 weeks of gestation is 10%, compared with a 90% survival rate in high-income countries.<ref>{{Cite book |last=March of Dimes Birth Defects Foundation. |title=Born too soon : the global action report on preterm birth |publisher=World Health Organization |year=2012 |isbn=978-92-4-150343-3 |oclc=1027675119}}</ref> In the United States, the period from 1980 to 2000 saw a decrease in the total number of infant mortality cases, despite a significant increase in premature births.<ref name="behrman-2007" />

Based on distinct clinical presentations, there are three main subgroups of preterm births: those that occur due to spontaneous premature labor, those that occur due to spontaneous membrane ([[amniotic sac]]) rupture, and those that are medically induced.<ref>{{Cite journal |last=Kramer |first=M. S. |date=October 1987 |title=Intrauterine growth and gestational duration determinants |url=https://pubmed.ncbi.nlm.nih.gov/3658568 |journal=Pediatrics |volume=80 |issue=4 |pages=502–511 |doi=10.1542/peds.80.4.502 |issn=0031-4005 |pmid=3658568 |s2cid=21632987}}</ref> Both spontaneous factors are viewed to be a result of similar causes; hence, two main classifications remain: spontaneous and medically induced causes.<ref>{{Cite journal |last=Klebanoff |first=M. A. |year=1998 |title=Conceptualizing categories of preterm birth |journal=Prenatal and Neonatal Medicine |volume=3 |issue=1 |pages=13–15}}</ref> The risk of spontaneous PTB increases with "extremes of maternal age (both young and old), short inter-pregnancy intervals, multiple gestations, assisted reproductive technology, prior PTB, family history, substance abuse, cigarette use, low maternal socioeconomic status, late or no prenatal care, low maternal prepregnancy weight, [[bacterial vaginosis]], [[periodontal disease]], and poor pregnancy weight gain."<ref>{{Cite journal |vauthors=Rubens CE, Sadovsky Y, Muglia L, Gravett MG, Lackritz E, Gravett C |date=November 2014 |title=Prevention of preterm birth: harnessing science to address the global epidemic |journal=Science Translational Medicine |volume=6 |issue=262 |pages=262sr5 |doi=10.1126/scitranslmed.3009871 |pmid=25391484 |s2cid=8162848 |doi-access=free}}</ref> Medically induced preterm birth is often conducted when continuing pregnancy poses significant risks to the pregnant parent or fetus; the most common causes include [[preeclampsia]], diabetes, maternal medical conditions, [[fetal distress]], or developmental problems.<ref name="Moutquin-2003" /> Despite these risk factors, the underlying causes of premature infant death are often unknown, and approximately 65% of all cases are not associated with any known risk factor.<ref name="harrison-2016" />

Infant mortality caused by premature birth is mainly attributed to developmental immaturity, which impacts multiple organ systems in the infant's body.<ref name="behrman-2007-2">{{Cite book |last1=Behrman |first1=Richard E. |url=https://www.ncbi.nlm.nih.gov/books/NBK11385/ |title=Mortality and Acute Complications in Preterm Infants |last2=Butler |first2=Adrienne Stith |last3=Outcomes |first3=Institute of Medicine (US) Committee on Understanding Premature Birth and Assuring Healthy |date=2007 |publisher=National Academies Press (US) |language=en}}</ref> The main body systems affected include the respiratory system, which may result in [[pulmonary hypoplasia]], [[Infant respiratory distress syndrome|respiratory distress syndrome]], [[bronchopulmonary dysplasia]] (a chronic lung disease), and [[apnea]].<ref name="behrman-2007-2" /> Other body systems that fully develop at a later gestational age include the [[Gastrointestinal tract|gastrointestinal system]], the skin, the [[immune system]], the [[cardiovascular system]], and the [[Blood|hematologic system]].<ref name="behrman-2007-2" /> Poor development of these systems increases the risk of infant mortality.{{cn|date=December 2023}}

Understanding the biological causes and predictors of PTB is important for identifying and preventing premature birth and infant mortality. While the exact mechanisms responsible for inducing premature birth are often unknown, many of the underlying risk factors are associated with inflammation. Approximately "80% of preterm births that occur at <1,000 g or at <28 to 30 weeks of gestation" have been associated with inflammation.{{citation needed|date=July 2023}} Biomarkers of inflammation, including [[C-reactive protein]], [[ferritin]], various [[interleukin]]s, [[chemokine]]s, [[cytokine]]s, [[defensin]]s, and [[bacteria]], have been shown to be associated with increased risks of infection or inflammation-related preterm birth. Biological fluids have been utilized to analyze these markers in hopes of understanding the pathology of preterm birth, but they are not always useful if not acquired at the appropriate gestational time-frame. For example, biomarkers such as [[fibronectin]] are accurate predictors of premature birth at over 24 weeks of gestation but have poor predictive values before then.<ref>{{Cite journal |vauthors=Goldenberg RL, Goepfert AR, Ramsey PS |date=May 2005 |title=Biochemical markers for the prediction of preterm birth |journal=American Journal of Obstetrics and Gynecology |volume=192 |issue=5 Suppl |pages=S36-46 |doi=10.1016/j.ajog.2005.02.015 |pmid=15891711}}</ref> Additionally, understanding the risks associated with different gestational ages is a helpful determiner of [[Gestational age-specific mortality]].<ref name="behrman-2007">{{Cite book |last1=Behrman |first1=Richard E. |url=https://www.ncbi.nlm.nih.gov/books/NBK11386/ |title=Prematurity at Birth: Determinants, Consequences, and Geographic Variation |last2=Butler |first2=Adrienne Stith |last3=Outcomes |first3=Institute of Medicine (US) Committee on Understanding Premature Birth and Assuring Healthy |date=2007 |publisher=National Academies Press (US) |language=en}}</ref>

==== Sudden infant death syndrome (SIDS) ====
{{Main|Sudden infant death syndrome}}

Sudden infant death syndrome (SIDS) is defined as the sudden death of an infant less than one year of age with no cause detected after a thorough investigation. SIDS is more common in Western countries.<ref name="Duncan_2018">{{Cite book |title=SIDS Sudden infant and early childhood death: The past, the present and the future |vauthors=Duncan JR, Byard RW, Duncan JR, Byard RW |publisher=University of Adelaide Press |year=2018 |isbn=9781925261677 |veditors=Duncan JR, Byard RW |pages=15–50 |chapter=Sudden Infant Death Syndrome: An Overview |jstor=10.20851/j.ctv2n7f0v.6 |pmid=30035964 |jstor-access=free}}</ref> The [[United States Centers for Disease Control and Prevention]] report SIDS to be the leading cause of death in infants aged one month to one year of life.<ref name="cdc.gov">{{Cite web |date=2020-01-28 |title=Sudden Unexpected Infant Death and Sudden Infant Death Syndrome |url=https://www.cdc.gov/sids/index.htm |access-date=2020-07-30 |website=www.cdc.gov |language=en-us}}</ref> Even though researchers are not sure what causes SIDS, they have found that putting babies to sleep on their backs, instead of their stomachs, lowers the risk. Campaigns like [[Safe to Sleep|Back to Sleep]] have used this research to lower the SIDS death rate by 50%.<ref>{{Cite journal |vauthors=Willinger M, Hoffman HJ, Hartford RB |date=May 1994 |title=Infant sleep position and risk for sudden infant death syndrome: report of meeting held January 13 and 14, 1994, National Institutes of Health, Bethesda, MD |url=http://pediatrics.aappublications.org/content/93/5/814.long |journal=Pediatrics |volume=93 |issue=5 |pages=814–9 |doi=10.1542/peds.93.5.814 |pmid=8165085 |s2cid=245121375}}</ref> Though the exact cause is unknown, the "triple-risk model" presents three factors that together may contribute to SIDS: smoking while pregnant, the age of the infant, and stress from conditions such as prone sleeping, [[co-sleeping]], overheating, and covering of the face or head.<ref name="Duncan_2018" /> In the early 1990s, it was argued that immunizations could contribute to an increased risk of SIDS; however, more recent support the idea that vaccinations reduce the risk of SIDS.<ref>{{Cite journal |vauthors=Vennemann MM, Höffgen M, Bajanowski T, Hense HW, Mitchell EA |date=June 2007 |title=Do immunisations reduce the risk for SIDS? A meta-analysis |journal=Vaccine |volume=25 |issue=26 |pages=4875–9 |doi=10.1016/j.vaccine.2007.02.077 |pmid=17400342}}</ref>

In the United States, approximately 3,500 infant deaths are sleep-related, a category that includes SIDS.<ref name="moon-2016">{{Cite journal |vauthors=Moon RY |date=November 2016 |title=SIDS and Other Sleep-Related Infant Deaths: Evidence Base for 2016 Updated Recommendations for a Safe Infant Sleeping Environment |journal=Pediatrics |volume=138 |issue=5 |pages=e20162940 |doi=10.1542/peds.2016-2940 |pmid=27940805 |s2cid=5744617 |doi-access=free}}</ref> To reduce sleep-related infant deaths, the American Academy of Pediatrics recommends providing infants with safe-sleeping environments, breastfeeding, and immunizing according to the recommended [[Vaccination schedule|immunization schedule]]. They recommend against the use of a [[pacifier]] and recommend avoiding exposure to smoke, alcohol, and illicit drugs during and after pregnancy.<ref name="moon-2016" />

==== Congenital malformations ====
{{Main|Congenital malformation}}

Congenital malformations are present at birth and include conditions such as cleft lip and palate, Down Syndrome, and heart defects. Some congenital malformations may be more likely when the mother consumes alcohol, but they can also be caused by genetics or unknown factors.<ref>{{Cite web |title=Medical Definition of Congenital malformation |url=https://www.medicinenet.com/script/main/art.asp?articlekey=2820 |website=MedicineNet.com |access-date=2018-07-25 |archive-date=2020-04-01 |archive-url=https://web.archive.org/web/20200401120742/https://www.medicinenet.com/script/main/art.asp?articlekey=2820 |url-status=dead }}</ref>
Congenital malformations have had a significant impact on infant mortality, but malnutrition and infectious diseases remain the main causes of death in less developed countries. For example, in the Caribbean and Latin America in the 1980s, congenital malformations only accounted for 5% of infant deaths, while malnutrition and infectious diseases accounted for 7% to 27% of infant deaths.<ref>{{Cite journal |vauthors=Rosano A, Botto LD, Botting B, Mastroiacovo P |date=September 2000 |title=Infant mortality and congenital anomalies from 1950 to 1994: an international perspective |journal=Journal of Epidemiology and Community Health |volume=54 |issue=9 |pages=660–6 |doi=10.1136/jech.54.9.660 |pmc=1731756 |pmid=10942444}}</ref> In more developed countries, such as the United States, there was a rise in infant deaths due to congenital malformations, mostly heart and central nervous system problems. In the 20th century, there was a decrease in the number of infant deaths from heart conditions, from 1979 to 1997, there was a 39% decline.<ref>{{Cite journal |vauthors=van der Linde D, Konings EE, Slager MA, Witsenburg M, Helbing WA, Takkenberg JJ, Roos-Hesselink JW |date=November 2011 |title=Birth prevalence of congenital heart disease worldwide: a systematic review and meta-analysis |journal=Journal of the American College of Cardiology |volume=58 |issue=21 |pages=2241–7 |doi=10.1016/j.jacc.2011.08.025 |pmid=22078432 |doi-access=free}}</ref>

=== Medicine and biology ===
Causes of infant mortality and deaths that are related to medical conditions include: low birth weight, [[sudden infant death syndrome]], malnutrition, congenital malformations, infectious diseases, and low income for health care, including [[neglected tropical diseases]].

The American Academy of Pediatrics recommends that infants need multiple doses of vaccines such as [[DPT vaccine|diphtheria–tetanus–acellular pertussis vaccine]], [[Hib vaccine|''Haemophilus influenzae'' type b (Hib) vaccine]], [[Hepatitis B vaccine|hepatitis B (HepB) vaccine]], [[Polio vaccine|inactivated polio vaccine]] (IPV), and [[pneumococcal vaccine]] (PCV). Research conducted by the [[Institute of Medicine]]'s [[Immunization Safety Review Committee]] concluded that there is no relationship between these vaccines and the risk of SIDS in infants.<ref>{{Cite book |last1=Institute of Medicine (US) Immunization Safety Review Committee |url=http://www.nap.edu/catalog/10649 |doi-access=free |title=Immunization Safety Review: Vaccinations and Sudden Unexpected Death in Infancy |last2=Stratton |first2=K. |last3=Almario |first3=D. A. |last4=Wizemann |first4=T. M. |last5=McCormick |first5=M. C. |date=2003-10-28 |publisher=National Academies Press |isbn=978-0-309-08886-2 |location=Washington, D.C. |doi=10.17226/10649 |pmid=25057654 |url-status=live |archive-url=https://web.archive.org/web/20231211061018/https://nap.nationalacademies.org/read/10649/chapter/1#ii |archive-date= Dec 11, 2023 }}</ref>{{rp|77–78}}

==== Low birth weight ====
{{Main|Low birth weight}}
[[Low birth weight]] makes up 60–80% of the infant mortality rate in developing countries. ''[[The New England Journal of Medicine]]'' stated that "The lowest mortality rates occur among infants weighing {{convert|3000|to|3500|g|lbs|abbr=on}}. For infants born weighing {{Convert|2500|g|lbs|abbr=on}} or less, the mortality rate rapidly increases with decreasing weight, and most of the infants weighing {{convert|1000|g|lbs|abbr=on}} or less die. As compared with normal-birth-weight infants, those with low weight at birth are almost 40 times more likely to die in the neonatal period; for infants with very low weight at birth the relative risk of neonatal death is almost 200 times greater."{{Quote without source|date=July 2023}} Infant mortality due to low birth weight is usually a direct cause stemming from other medical complications such as preterm birth, poor maternal nutritional status, a lack of [[prenatal care]], maternal sickness during pregnancy, and unhygienic home environments.<ref name="Andrews" /> Birth weight and the length of gestation are the two most important predictors of an infant's chances of survival and their overall health.<ref name="MacDorman 2009" />

According to the ''New England Journal of Medicine'', "in the past two decades, the infant mortality rate (deaths under one year of age per thousand live births) in the United States has declined sharply."{{Quote without source|date=July 2023}} The rate of low birth weights among African Americans remains twice as high as the rate for white people. Low birth weight, the leading cause of infant deaths, is preventable by effective programs to help prevent low birth weight are a combination of health care, education, the environment,{{Clarify span|mental modification,|date=August 2023}} and public policy.<ref>{{Cite web |year=2000 |title=Infant Mortality, Low Birthweight and Racial Disparity |url=http://www.nationalhealthystart.org/site/assets/docs/Infant%20Mortality%20Low%20Birthweight.pdf |archive-url=https://web.archive.org/web/20191230004308/http://www.nationalhealthystart.org/site/assets/docs/Infant%20Mortality%20Low%20Birthweight.pdf |archive-date=2019-12-30 |website=National Healthy Start Association }}</ref> Preterm birth is the leading cause of newborn deaths worldwide.<ref>{{Cite web |title= Preterm birth |url=https://www.who.int/mediacentre/factsheets/fs363/en/index.html |access-date=2013-09-29 |website=WHO |date=November 2012 |url-status=dead |archive-url= https://web.archive.org/web/20131002115944/https://www.who.int/mediacentre/factsheets/fs363/en/index.html |archive-date= Oct 2, 2013 }}</ref> Even though America has a higher survival rate for premature infants, the percentage of Americans who deliver prematurely is comparable to those in developing countries. Reasons for this include [[teenage pregnancy]], an increase in pregnancy after the age of 35, an increase in the use of [[in vitro fertilisation]] (which increases the risk of multiple births), obesity, and diabetes. Also, pregnant people who do not have access to health care are less likely to visit a doctor, therefore increasing their risk of delivering prematurely.<ref name="lag" />

====Malnutrition====
{{Main|Undernutrition in children}}
[[File:Hunger Map 2020 World Food Programme.svg|thumb|310px|Percentage of population suffering from hunger, [[World Food Programme]], 2020<br>
{{Legend|#29b8c7|< 2,5%}}
{{Legend|#16b484|2,5–5,0%}}
{{Legend|#fec960|5,0–14,9%}}
{{Legend|#f47846|15,0–24,9%}}
{{Legend|#f2203a|25,0–34,9%}}
{{Legend|#7f0928|> 35,0%}}
{{Legend|#b5aba4|No data}}]]
Malnutrition or undernutrition is defined as inadequate intake of nourishment, such as proteins and vitamins, which adversely affects the growth, energy, and development of people all over the world.<ref>{{Cite journal |vauthors=de Onís M, Monteiro C, Akré J, Glugston G |date=1993 |title=The worldwide magnitude of protein-energy malnutrition: an overview from the WHO Global Database on Child Growth |journal=Bulletin of the World Health Organization |volume=71 |issue=6 |pages=703–12 |pmc=2393544 |pmid=8313488 }}</ref> It is especially prevalent during pregnancy and in infants and children under 5 who live in developing countries within the poorer regions of Africa, Asia, and Latin America.<ref>{{Cite news |date=2012-09-26 |title=Top 9 countries fighting child malnutrition |first1=Kathryn |last1=Reid |work=World Vision |url=https://www.worldvision.org/hunger-news-stories/top-nine-countries-fighting-child-malnutrition |access-date=2018-07-27}}</ref> Children are especially vulnerable as they have yet to fully develop a strong [[immune system]] and are dependent on their parents to provide the necessary food and nutritional intake. It is estimated that about 3.5 million children die each year as a result of childhood or maternal malnutrition, with [[stunted growth]], low body weight, and low birth weight accounting for about 2.2 million associated deaths.<ref>{{Cite journal |display-authors=6 |vauthors=Martins VJ, Toledo Florêncio TM, Grillo LP, do Carmo P, Franco M, Martins PA, Clemente AP, Santos CD, de Fatima A, Vieira M, Sawaya AL |date=June 2011 |title=Long-lasting effects of undernutrition |journal=International Journal of Environmental Research and Public Health |volume=8 |issue=6 |pages=1817–46 |doi=10.3390/ijerph8061817 |pmc=3137999 |pmid=21776204 |doi-access=free}}</ref> Socioeconomic and environmental factors contribute to malnutrition, as do gender, location, and cultural practices surrounding [[breastfeeding]].<ref>{{Cite journal |vauthors=Mahgoud SE |date=2006 |title=Factors Affecting Prevalence of Malnutrition Among Children Under Three Years Of Age In Botswana |url=https://ubrisa.ub.bw/bitstream/handle/10311/219/Mahgoub_AJFAND_2006.pdf?sequence=1&isAllowed=y |journal=African Journal of Food, Agriculture, Nutrition and Development |volume=6}}</ref> It is difficult to assess the most pressing factor as they can intertwine and vary among regions.

Children suffering from malnutrition can become underweight, and experience stunting or [[wasting]]. In Africa, the number of stunted children has risen, while Asia has the most children under 5 suffering from wasting.<ref>{{Cite web |date=2015 |title=Levels and trends in child malnutrition |url=https://www.unicef.org/media/files/JME_2015_edition_Sept_2015.pdf |url-status=dead |archive-url=https://web.archive.org/web/20210525180258/https://www.unicef.org/media/files/JME_2015_edition_Sept_2015.pdf |archive-date=2021-05-25 |access-date=2018-07-27 |website=UNICEF – WHO – World Bank Group joint child malnutrition estimates}}{{Moved resource|date=July 2023}}</ref> Inadequate nutrients adversely affect physical and cognitive development, increasing susceptibility to severe health problems. Micronutrient deficiency has been linked to [[Iron-deficiency anemia|anemia]], fatigue, [[Vitamin A deficiency#Signs and symptoms|blindness]], [[Iodine deficiency#Goiter|goiter]], poor brain development, and death.<ref>{{Cite journal |vauthors=Torpy JM, Lynm C, Glass RM |date=August 2004 |title=JAMA patient page. Malnutrition in children |journal=JAMA |volume=292 |issue=5 |pages=648 |doi=10.1001/jama.292.5.648 |pmid=15292091 |doi-access=free}}</ref> Malnutrition also decreases the immune system's ability to fight infections, resulting in higher rates of death from diseases such as malaria, respiratory disease, and diarrhea.<ref>{{Cite journal |vauthors=Tette EM, Sifah EK, Nartey ET |date=November 2015 |title=Factors affecting malnutrition in children and the uptake of interventions to prevent the condition |journal=BMC Pediatrics |volume=15 |issue=1 |pages=189 |doi=10.1186/s12887-015-0496-3 |pmc=4653928 |pmid=26586172 |doi-access=free }}</ref>

[[Folic acid]] during pregnancy is one way to combat iron deficiency. A few [[public health]] measures used to lower levels of iron deficiency anemia include added iodine to salt or drinking water and including vitamin A and multivitamin supplements in the diet.<ref name="Andrews" /> A deficiency of this vitamin causes certain types of [[anemia]] (low red blood cell count).<ref>{{Cite web |title=Folic Acid |url=http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0000723 |archive-url=https://web.archive.org/web/20100714151130/http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0000723 |archive-date=14 July 2010 |website=PubMed Health |publisher=]National Center for Biotechnology Information, U.S. National Library of Medicine}}</ref>

====Infectious diseases====
Babies born in low- to middle-income countries in sub-Saharan Africa and southern Asia are at the highest risk of neonatal death. Bacterial infections of the bloodstream, lungs, and the brain's covering ([[meningitis]]) are responsible for 25% of neonatal deaths worldwide. Newborns can acquire infections during birth from bacteria present in the birth canal, the person may not be aware of the infection, or they may have an untreated [[pelvic inflammatory disease]] or a [[sexually transmitted disease]]. These bacteria can also move up the vaginal canal into the amniotic sac surrounding the baby causing in utero transmission. Maternal blood-borne infection is another route of bacterial infection. Neonatal infection is more likely with the [[premature rupture of the membranes]] (PROM) of the amniotic sac.<ref>{{Cite journal |vauthors=Chan GJ, Lee AC, Baqui AH, Tan J, Black RE |date=August 2013 |title=Risk of early-onset neonatal infection with maternal infection or colonization: a global systematic review and meta-analysis |journal=PLOS Medicine |volume=10 |issue=8 |pages=e1001502 |doi=10.1371/journal.pmed.1001502 |pmc=3747995 |pmid=23976885 |doi-access=free }}</ref>

Seven out of ten childhood deaths are due to infectious diseases like [[acute respiratory infection]], [[diarrhea]], [[measles]], and [[malaria]]. Acute respiratory infections such as [[pneumonia]], [[bronchitis]], and [[bronchiolitis]] account for 30% of childhood deaths; 95% of pneumonia cases occur in the developing world. Diarrhea is the second-largest cause of childhood mortality in the world, while malaria causes 11% of childhood deaths. Measles is the fifth-largest cause of childhood mortality.<ref name="Andrews" /><ref name="Nussbaum">{{Cite book |title=Creating Capabilities |vauthors=Nussbaum M |publisher=The Belknap Press of Harvard University Press |year=2011 |isbn=978-0-674-05054-9}}</ref>

===Environmental===
The infant mortality rate is one measure of a nation's health and social conditions. Its causes are a composite of a number rates that each have their own separate relationships with each other and with various other social factors. As such, IMR can often be seen as an indicator to measure the level of socioeconomic disparity within a country.<ref name="MacDorman 2009">{{Cite journal |vauthors=MacDorman MF, Mathews TJ |year=2009 |title=The challenge of infant mortality: have we reached a plateau? |doi-access=free |journal=Public Health Reports |volume=124 |issue=5 |pages=670–81 |doi=10.1177/003335490912400509 |pmc=2728659 |pmid=19753945}}</ref><ref name="Gortmaker 1997">{{Cite journal |vauthors=Gortmaker SL, Wise PH |year=1997 |title=The first injustice: socioeconomic disparities, health services technology, and infant mortality |journal=Annual Review of Sociology |volume=23 |pages=147–70 |doi=10.1146/annurev.soc.23.1.147 |pmid=12348279}}</ref>

Organic [[water pollution]] is a better indicator of infant mortality than health expenditures per capita. Water contaminated by animal waste houses various [[pathogens]] including a host of [[parasitic]] and [[microbial]] infections.<ref name="Jorgenson">{{Cite journal |vauthors=Jorgenson AK |year=2004 |title=Global inequality, water pollution, and infant mortality |journal=The Social Science Journal |volume=41 |issue=2 |pages=279–288 |doi=10.1016/j.soscij.2004.01.008 |s2cid=154147986}}</ref> Areas of low [[socioeconomic status]] are more prone to inadequate plumbing infrastructure and poorly maintained facilities.<ref name="Andrews" /> Climate and geography often play a role in sanitation conditions. For example, the inaccessibility of clean water exacerbates poor sanitation conditions.<ref name="Jorgenson" />

The burning of inefficient fuels doubles the rate of acute respiratory tract infections in children under 5 years old.<ref name="Andrews" /> People who live in areas where [[particulate matter]] air pollution is higher tend to have more health problems regardless of age. The short and long-term effects of [[air pollution]] are associated with an increased mortality rate, including infant mortality. Air pollution is consistently associated with postnatal mortality due to respiratory effects and sudden infant death syndrome (SIDS). Specifically, air pollution is highly associated with SIDS in the United States during the post-neonatal stage.<ref>{{Cite journal |vauthors=Woodruff TJ, Darrow LA, Parker JD |date=January 2008 |title=Air pollution and postneonatal infant mortality in the United States, 1999-2002 |journal=Environmental Health Perspectives |volume=116 |issue=1 |pages=110–5 |doi=10.1289/ehp.10370 |pmc=2199284 |pmid=18197308|bibcode=2008EnvHP.116..110W }}</ref> High infant mortality is exacerbated because newborns are a vulnerable subgroup that is affected by air pollution.<ref>{{Cite journal |vauthors=Glinianaia SV, Rankin J, Bell R, Pless-Mulloli T, Howel D |date=October 2004 |title=Does particulate air pollution contribute to infant death? A systematic review |journal=Environmental Health Perspectives |volume=112 |issue=14 |pages=1365–71 |doi=10.1289/ehp.6857 |pmc=1247561 |pmid=15471726|bibcode=2004EnvHP.112.1365G }}</ref> Newborns who were born into these environments are no exception, and pregnant women exposed to greater air pollution on a daily basis should be closely watched by their doctors, including after the baby is born. Babies who live in areas with less air pollution have a greater chance of living until their first birthday, meaning babies who live in environments with more air pollution are at greater risk for infant mortality. Areas that have higher air pollution also have a greater chance of having a higher population density, higher crime rates, and lower income levels, all of which can lead to higher infant mortality rates.<ref>{{Cite web |title=Infant Mortality: Reducing Infant Deaths. |url=http://www.nichd.nih.gov/news/resources/advances/2005/infant.cfm |url-status=dead |archive-url=https://web.archive.org/web/20111012190945/http://www.nichd.nih.gov/news/resources/advances/2005/infant.cfm |archive-date=12 October 2011 |publisher=[[Eunice Kennedy Shriver National Institute of Child Health and Human Development]]}}</ref>

A key pollutant in infant mortality rates is [[carbon monoxide]]. Carbon monoxide is a colorless, odorless gas that can kill, and is especially dangerous to infants because of their immature respiratory systems.<ref>{{Cite journal |vauthors=Benjamin DK |date=Winter 2006 |title=Air Pollution and Infant Mortality |url=http://perc.org/articles/air-pollution-and-infant-mortality |journal=Property and Environmental Research Center Report |volume=24 |issue=4}}</ref>
Another major pollutant that can have detrimental effects on a fetus is second-hand smoke.

{{Blockquote|source=''American Journal of Public Health''|text=[I]n 2006, more than 42,000 Americans died of secondhand smoke-attributable diseases, including more than 41,000 adults and nearly 900 infants. Fully 36% of the infants who died of low birth weight caused by exposure to maternal smoking in utero were black, as were 28% of those dying of respiratory distress syndrome, 25% dying of other respiratory conditions, and 24% dying of sudden infant death syndrome.}}

{{Blockquote|source=''The American Journal of Epidemiology''|text=Compared with nonsmoking women having their first birth, women who smoked less than one pack of cigarettes per day had a 25% greater risk of mortality, and those who smoked one or more packs per day had a 56% greater risk. Among women having their second or higher birth, smokers experienced 30% greater mortality than nonsmokers.}}

Modern research in the United States into racial disparities in infant mortality suggests a link between [[institutionalized racism]] and high rates of African American infant mortality. In synthesis{{Synthesis inline|date=July 2023}} of this research, it has been observed that "African American infant mortality remains elevated due to the social arrangements that exist between groups and the lifelong experiences responding to the resultant power dynamics of these arrangements."<ref name="Osel2008" />

It is important to note that infant mortality rates do not decline among African Americans if their socio-economic status improves. Parker Dominguez at the University of Southern California<ref>{{Cite web |title=Tyan Parker Dominguez {{!}} USC Social Work |url=https://dworakpeck.usc.edu/academics/faculty-directory/tyan-parker-dominguez |access-date=2024-03-16 |website=dworakpeck.usc.edu |language=en}}</ref> has made some headway in determining the reasons behind this, claiming black women in the US are more prone to psychological stress than women of other races. Stress is a leading factor in the start of labor, and therefore, high levels of stress during pregnancy could lead to premature births that have the potential to be fatal for the infant.<ref>{{Cite news |date=2014-03-03 |title=Why do black infants die so much more often than white infants? |work=Southern California Public Radio |url=http://www.scpr.org/news/2014/03/03/42483/why-do-black-infants-die-so-much-more-often-than-w/ |access-date=2017-02-07}}</ref>

====Early childhood trauma====
[[Early childhood trauma]] includes physical, sexual, and psychological abuse of a child from birth to five years old. [[Childhood trauma|Trauma]] in early childhood has an extreme impact over the course of a lifetime and is a significant contributor to infant mortality. Developing organs are fragile, when an infant is shaken, beaten, strangled, or raped, the impact is exponentially more destructive than when the same abuse occurs to a fully developed body.{{Fact or opinion|date=July 2023}} Studies estimate that 1–2 per 100,000 U.S. children are fatally injured annually, and it is reasonable to assume that these statistics underrepresent actual mortality.<ref name="child welfare">{{Cite book |last=Child Welfare Information Gateway |url=https://www.childwelfare.gov/pubpdfs/fatality.pdf |title=Child Abuse and Neglect Fatalities 2018: Statistics and Interventions |date=2020 |publisher=Children's Bureau, U.S. Department of Health and Human Services |location=Washington, DC |access-date=22 October 2020 |archive-date=16 October 2020 |archive-url=https://web.archive.org/web/20201016192931/https://www.childwelfare.gov/pubPDFs/fatality.pdf |url-status=dead }}</ref><ref>{{Cite journal |vauthors=Palusci VJ, Covington TM |date=January 2014 |title=Child maltreatment deaths in the U.S. National Child Death Review Case Reporting System |journal=Child Abuse & Neglect |volume=38 |issue=1 |pages=25–36 |doi=10.1016/j.chiabu.2013.08.014 |pmid=24094272}}</ref> Almost three-quarters (70.6%) of child fatalities in [[Fiscal year|FFY]] 2018 involved children younger than 3 years, and children younger than 1 year accounted for half (49.4%) of all fatalities.<ref name="child welfare" /> In particular, correctly identifying deaths due to neglect is problematic, and children with sudden, unexpected deaths or deaths from apparently unintentional causes often have preventable risk factors that are substantially similar to those in families with maltreatment.{{citation needed|date=August 2023}}

There is a direct relationship between the age at which maltreatment or injury occurs and the risk of death. The younger an infant is, the more dangerous the maltreatment.<ref>{{Cite journal |vauthors=Imamura JH, Troster EJ, Oliveira CA |date=September 2012 |title=What types of unintentional injuries kill our children? Do infants die of the same types of injuries? A systematic review |journal=Clinics |volume=67 |issue=9 |pages=1107–16 |doi=10.6061/clinics/2012(09)20 |pmc=3438254 |pmid=23018311}}</ref>{{Failed verification|date=July 2023|reason=Improper synthesis?}}

Family configuration,<ref>{{Cite journal |vauthors=Smith-Greenaway E, Trinitapoli J |date=April 2014 |title=Polygynous contexts, family structure, and infant mortality in sub-saharan Africa |journal=Demography |volume=51 |issue=2 |pages=341–66 |doi=10.1007/s13524-013-0262-9 |pmc=3974908 |pmid=24402794}}</ref><ref>{{Cite web |title=Child Maltreatment: Risk and Protective Factors |url=https://www.cdc.gov/violenceprevention/childmaltreatment/riskprotectivefactors.html |url-status=dead |archive-url=https://web.archive.org/web/20100306061203/https://www.cdc.gov/violenceprevention/childmaltreatment/riskprotectivefactors.html |archive-date=6 March 2010 |website=Centers for Disease Control and Prevention}}</ref> child gender, social isolation, lack of support, maternal youth, marital status, [[poverty]], parental [[Adverse Childhood Experiences Study|adverse childhood experiences]], and parenting practices<ref>{{Cite journal |vauthors=Leventhal JM, Garber RB, Brady CA |date=March 1989 |title=Identification during the postpartum period of infants who are at high risk of child maltreatment |journal=The Journal of Pediatrics |volume=114 |issue=3 |pages=481–7 |doi=10.1016/S0022-3476(89)80580-3 |pmid=2921696}}</ref> are all thought to contribute to increased risk.<ref name="child welfare" />

====Socio-economic factors====
[[File:Infant mortality rates are higher in more unequal countries.jpg|thumb|Infant mortality rates are higher in countries with higher [[economic inequality]].]]
[[Social class]] is a major factor in infant mortality, both historically and today. Between 1912 and 1915, the Children's Bureau in the United States examined data across eight cities and nearly 23,000 live births. They discovered that lower [[income]]s tended to [[correlation|correlate]] with higher infant mortality. In cases where the father had no income, the rate of infant mortality was 357% higher than that for the highest income earners ($1,250+).<ref name="ReferenceA" />{{rp|5}} Differences between [[race (classification of humans)|races]] were also apparent. African-American mothers experience infant mortality at a rate 44% higher than average;<ref name="ReferenceA">{{Cite journal |vauthors=Haines MR |year=2011 |title=Inequality and infant and childhood mortality in the United States in the twentieth century |url=http://www.nber.org/papers/w16133.pdf |journal=Explorations in Economic History |volume=48 |issue=3 |pages=418–28 |doi=10.1016/j.eeh.2011.05.009 |s2cid=154583453 |ssrn=1630138}}</ref> however, research indicates that socio-economic factors do not totally account for the racial disparities in infant mortality.<ref name="Osel2008" />

[[File:Countries by GDP (nominal) per capita in 2019.svg|thumb|left|270x270px|Countries by 2019 [[List of countries by GDP (nominal) per capita|GDP (nominal) per capita]]{{efn|Data from the [[United Nations]] is used.}}]]

While infant mortality is normally negatively correlated with GDP, there may be some beneficial short-term effects from a recession. A 2009 study in ''[[The Economist]]'' showed that economic slowdowns reduce air pollution, which results in a lower infant mortality rate. In the late 1970s and early 1980s, the recession's impact on air quality was estimated to have saved around 1,300 US babies.<ref>{{Cite news |date=2009-06-01 |title=A recession breathes life |newspaper=The Economist |url=http://www.economist.com/research/articlesBySubject/displaystory.cfm?subjectid=7933604&story_id=13764868 |archive-url=https://web.archive.org/web/20090725034036/http://www.economist.com/research/articlesBySubject/displaystory.cfm?subjectid=7933604&story_id=13764868 |archive-date=2009-07-25}}</ref> It is only during deep recessions that infant mortality increases. According to Norbert Schady and Marc-François Smitz, recessions when [[per capita GDP]] drops by 15% or more increase IMR.<ref>{{Cite web |last1=Schady |first1=Norbert |last2=Smitz |first2=Marc |date=August 2009 |title=Aggregate Economic Shocks and Infant Mortality: New Evidence for Middle-Income Countries |url=http://siteresources.worldbank.org/INTAFRICA/Resources/SchadySmitz_080509.pdf |website=The World Bank}}</ref>

Social class dictates which medical services are available to an individual. Disparities due to [[socioeconomic]] factors have been highlighted by advances in medical [[technology]]. Developed countries, most notably the United States, have seen a divergence in IMR between those living in poverty who cannot afford medically advanced resources, and those who can.<ref name="Gortmaker 1997" />

Developing nations with democratic governments tend to be more responsive to public opinion, [[social movements]], and [[special interest groups]] on issues like infant mortality. In contrast, non-democratic governments are more interested in corporate issues than in health issues. Democratic status affects the dependency a nation has on its economic state via exports, investments from multinational corporations, and international lending institutions.<ref name="Shandra">{{Cite journal |vauthors=Shandra JM, Nobles J, London B, Williamson JB |date=July 2004 |title=Dependency, democracy, and infant mortality: a quantitative, cross-national analysis of less developed countries |url=http://www.escholarship.org/uc/item/1wm303dg |journal=Social Science & Medicine |volume=59 |issue=2 |pages=321–333 |doi=10.1016/j.socscimed.2003.10.022 |pmid=15110423 |s2cid=616916}}</ref>

Levels of socioeconomic development and global integration are inversely related to a nation's infant mortality rate, meaning that as they increase, IMR decreases.<ref name="Andrews" /><ref name="Fuse">{{Cite journal |vauthors=Fuse K, Crenshaw EM |date=January 2006 |title=Gender imbalance in infant mortality: a cross-national study of social structure and female infanticide |journal=Social Science & Medicine |volume=62 |issue=2 |pages=360–74 |doi=10.1016/j.socscimed.2005.06.006 |pmid=16046041}}</ref> A nation's internal impact is highly influenced by its position in the global economy, which has adverse effects on the survival of children in developing countries.<ref name="Jorgenson" /> Countries can experience disproportionate effects from [[trade]] and stratification within the global system,<ref>{{Cite journal |vauthors=Moore S, Teixeira AC, Shiell A |date=July 2006 |title=The health of nations in a global context: trade, global stratification, and infant mortality rates |url=https://www.researchgate.net/publication/7316172 |journal=Social Science & Medicine |volume=63 |issue=1 |pages=165–78 |doi=10.1016/j.socscimed.2005.12.009 |pmid=16457924}}</ref> which contributes to the global [[division of labor]], and distorts the [[domestic economy|domestic economies]] of developing nations. The dependency of developing nations can reduce the rate of economic growth, increase income inequality inter- and intra-nationally, and adversely affect the wellbeing of a nation's population. Collective cooperation between  countries plays a role in development policies in the poorer countries of the world.<ref name="Shandra" />{{Explain|date=July 2023|reason=Jargon heavy paragraph is hard to follow for the non-economist.}}

These economic factors present challenges to governments' public [[health policy|health policies]].<ref name="Jorgenson" /> If the nation's ability to raise its own revenues is compromised, governments will lose funding for their health service programs, including those that aim to decrease infant mortality rates.<ref name="Shandra" /> Less developed countries face higher levels of vulnerability to the possible negative effects of globalization and trade in relation to more developed countries.<ref name="Jorgenson" />

Even with a strong economy and economic growth (measured by a country's [[gross national product]]), the advances of medical technologies may not be felt by everyone, increasing social disparities.<ref name="Gortmaker 1997" /> In England, from 2014 to 2017, a rise in infant mortality was disproportionately experienced by the poorest regions, where the previously declining trend was reversed and an additional 24 infant deaths per 100,000 live births occurred annually.<ref>{{Cite journal |display-authors=6 |vauthors=Taylor-Robinson D, Lai ET, Wickham S, Rose T, Norman P, Bambra C, Whitehead M, Barr B |date=October 2019 |title=Assessing the impact of rising child poverty on the unprecedented rise in infant mortality in England, 2000-2017: time trend analysis |journal=BMJ Open |volume=9 |issue=10 |pages=e029424 |doi=10.1136/bmjopen-2019-029424 |pmc=6954495 |pmid=31578197}}</ref>

====War====
Infant mortality rates correlate with [[war]], political unrest, and [[government corruption]].<ref name="Andrews" /> In most cases, war-affected areas will experience a significant increase in infant mortality rates. Having a war take place when planning pregnancy is not only stressful on the mother and fetus but also has several detrimental effects.<ref>{{Cite journal |last=Abouharb |first=M. Rodwan |date=2023-03-16 |title=War and infant mortality rates |url=https://www.tandfonline.com/doi/full/10.1080/14754835.2022.2122786 |journal=[[PLOS Medicine]] |volume=22 |issue=2 |pages=135-157 |doi=10.1080/14754835.2022.2122786 |issn=1475-4835 |via=[[Taylor & Francis Online]]}}</ref><ref>{{Cite journal |last1=Jawad |first1=Mohammed |last2=Hone |first2=Thomas |last3=Vamos |first3=Eszter P. |last4=Cetorelli |first4=Valeria |last5=Millett |first5=Christopher |date=2021-09-28 |title=Implications of armed conflict for maternal and child health: A regression analysis of data from 181 countries for 2000–2019 |journal=PLOS Medicine |language=en |volume=18 |issue=9 |pages=e1003810 |doi=10.1371/journal.pmed.1003810 |doi-access=free |issn=1549-1676 |pmc=8478221 |pmid=34582455}}</ref>

Many other significant factors influence infant mortality rates in war-torn areas. Health care systems in developing countries in the midst of war often collapse, and obtaining basic medical supplies and care becomes increasingly difficult. During the [[Yugoslav Wars]] in the 1990s, Bosnia experienced a 60% decrease in child immunizations. Preventable diseases can quickly become epidemics during war.<ref name="Krug_2002">{{Cite book |url=https://www.who.int/violence_injury_prevention/violence/world_report/en/ |title=World Report on Violence and Health |vauthors=Krug E |publisher=Geneva WHO |year=2002 |location=Geneva}}</ref>

Many developing countries rely on foreign aid for basic nutrition, and transport of aid becomes significantly more difficult in times of war. In most situations, the average weight of a population will drop substantially.<ref>{{Cite journal |vauthors=Toole MJ, Galson S, Brady W |date=May 1993 |title=Are war and public health compatible? |url=https://zenodo.org/record/1258317 |journal=Lancet |volume=341 |issue=8854 |pages=1193–6 |doi=10.1016/0140-6736(93)91013-C |pmid=8098086 |s2cid=7743798}}</ref> Expectant mothers are affected even more by a lack of access to food and water. During the Yugoslav Wars in Bosnia, the number of premature babies born increased and the average birth weight decreased.<ref name="Krug_2002" />

There have been several instances in recent years of systematic rape as a weapon of war. People who become pregnant as a result of war rape face even more significant challenges in bearing a healthy child. Studies suggest that people who experience sexual violence before or during pregnancy are more likely to experience infant death.<ref>{{Cite journal |vauthors=Asling-Monemi K, Peña R, Ellsberg MC, Persson LA |year=2003 |title=Violence against women increases the risk of infant and child mortality: a case-referent study in Nicaragua |journal=Bulletin of the World Health Organization |volume=81 |issue=1 |pages=10–6 |pmc=2572309 |pmid=12640470}}</ref><ref>{{Cite journal |vauthors=Emenike E, Lawoko S, Dalal K |date=March 2008 |title=Intimate partner violence and reproductive health of women in Kenya |journal=International Nursing Review |volume=55 |issue=1 |pages=97–102 |doi=10.1111/j.1466-7657.2007.00580.x |pmid=18275542}}</ref><ref>{{Cite journal |vauthors=Jejeebhoy SJ |date=September 1998 |title=Associations between wife-beating and fetal and infant death: impressions from a survey in rural India |journal=Studies in Family Planning |volume=29 |issue=3 |pages=300–8 |doi=10.2307/172276 |jstor=172276 |pmid=9789323}}</ref> Causes of infant mortality after abuse during pregnancy range from physical side effects of the initial trauma to psychological effects that lead to poor adjustment to society.<ref>{{Cite journal |vauthors=Fisher SK |date=October 1996 |title=Occupation of the Womb: Forced Impregnation as Genocide |url=https://scholarship.law.duke.edu/dlj/vol46/iss1/4 |journal=Duke Law Journal |volume=46 |issue=1 |pages=91–133 |doi=10.2307/1372967 |jstor=1372967}}</ref> Many people who became pregnant by rape in Bosnia were isolated from their hometowns, making life after childbirth exponentially more difficult.<ref>{{Cite journal |last=Theidon |first=Kimberly |date=1 December 2015 |title=Hidden in Plain Sight |url=https://www.journals.uchicago.edu/doi/10.1086/683301 |journal=Current Anthropology |volume=56 |issue=S12 |pages=S191–S200 |doi=10.1086/683301 |issn=0011-3204}}</ref>
=== Culture ===
High rates of infant mortality occur in developing countries where financial and material resources are scarce, and where there is a high tolerance for infant deaths. There are a number of developing countries where certain cultural situations, such as favoring male babies over female babies, are the norm.<ref name="Andrews" /> In developing countries such as Brazil, infant mortality rates are commonly not recorded due to not registering for death certificates.<ref name="Nations">{{Cite journal |vauthors=Nations MK, Amaral ML |year=1991 |title=Flesh, Blood, Souls, and Households: Cultural Validity in Mortality Inquiry |journal=Medical Anthropology Quarterly |volume=5 |issue=3 |pages=204–220 |doi=10.1525/maq.1991.5.3.02a00020}}</ref> Another cultural reason for infant mortality, such as what is happening in Ghana, is that "besides the obvious, like rutted roads, there are prejudices against wives or newborns leaving the house."<ref>{{Cite web |date=October 29, 2012 |title=Ghana: A grant meant to curb infant mortality focuses on getting mothers to the hospital |url=https://www.nytimes.com/2012/10/30/health/gates-foundation-backs-hospital-transportation-for-expectant-mothers.html |url-access=subscription |website=The New York Times |vauthors=McNeil D}}</ref> This makes it even more difficult for pregnant women and newborns to get the needed treatment that is available to them.

In the United States cultural influences and lifestyle habits can account for some infant deaths. Examples include [[teenage pregnancy]], [[obesity]], [[diabetes]], and [[smoking]]. All are possible causes of premature births, which constitute the second-highest cause of infant mortality.<ref name="lag">{{Cite web |date=May 2, 2012 |title=U.S. Lags in Global Measure of Premature Births |url=https://www.nytimes.com/2012/05/03/health/us-lags-in-global-measure-of-preterm-births.html |url-access=subscription |website=The New York Times |vauthors=McNeil D |url-status=live |archive-url= https://web.archive.org/web/20230410044313/https://www.nytimes.com/2012/05/03/health/us-lags-in-global-measure-of-preterm-births.html |archive-date= Apr 10, 2023 }}</ref> According to the Journal of the American Medical Association, "the post neonatal mortality risk (28 to 364 days) was highest among continental Puerto Ricans" compared to non-Hispanic babies. Ethnic differences are accompanied by a higher prevalence of behavioral risk factors and sociodemographic challenges that each ethnic group faces.<ref name="MacDorman 2009" />

====Male sex favoritism====
Historically, males have had higher infant mortality rates than females, with the difference being dependent on environmental, social, and economic conditions. More specifically, males are biologically more vulnerable to infections and conditions associated with prematurity and development. Before 1970, the reasons for male infant mortality were infections and chronic degenerative diseases. However, since 1970, male sex favoritism in certain cultures has led to a decrease in the infant mortality gap between males and females. Also, medical advances have resulted in a greater effect on the survival rate of male infants than female infants, due to the initial high infant mortality rate of males.<ref name="Dreven">{{Cite journal |vauthors=Drevenstedt GL, Crimmins EM, Vasunilashorn S, Finch CE |date=April 2008 |title=The rise and fall of excess male infant mortality |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=105 |issue=13 |pages=5016–21 |bibcode=2008PNAS..105.5016D |doi=10.1073/pnas.0800221105 |pmc=2278210 |pmid=18362357 |doi-access=free }}</ref>

Genetic components result in newborn females being at a biological advantage when it comes to surviving their first birthday, versus newborn males, who have lower chances of surviving infancy. As infant mortality rates decreased globally, the gender ratios changed from males being at a biological disadvantage to females facing a societal disadvantage.<ref name="Dreven" /> Some developing nations have social and cultural patterns that favor boys over girls for their future earning potential. A country's ethnic composition, [[Monoethnicity|homogeneous]] or [[Polyethnicity|heterogeneous]], can explain social attitudes and practices. Heterogeneous levels are a strong predictor of infant mortality.<ref name="Fuse" />{{Verify source|date=July 2023}}

====Birth spacing====
[[File:Total Fertility Rate Map by Country.svg|thumb|right|upright=1.35|Map of countries by fertility rate, according to the [[Population Reference Bureau]]]]
Birth spacing is the time between births. Births spaced at least three years apart are associated with the lowest rate of mortality. The longer the interval between births, the lower the risk of having complications at birth, or of infant, childhood, or [[maternal mortality]].<ref name="Norton" /><ref name="Rutstein">{{Cite journal |vauthors=Rutstein SO |date=April 2005 |title=Effects of preceding birth intervals on neonatal, infant and under-five years mortality and nutritional status in developing countries: evidence from the demographic and health surveys |journal=International Journal of Gynaecology and Obstetrics |volume=89 |issue=Suppl 1 |pages=S7-24 |doi=10.1016/j.ijgo.2004.11.012 |pmid=15820369 |s2cid=37743580}}</ref> Conception less than six months after a birth, abortion, or miscarriage is associated with higher rates of preterm births and low birth weight, and also increases the chances of [[Chronic condition|chronic]] and general undernutrition. In 55 developing countries 57% of reported pregnancies had birth spaces of less than three years, and 26% of less than two years. While only 20% of new parents report wanting another birth within two years, only 40% are taking steps like [[family planning]] to achieve this.<ref name="Norton" />

Unplanned pregnancies and birth intervals of less than twenty-four months are known to correlate with low birth weights and delivery complications. Also, mothers who are already small in stature tend to deliver smaller than average babies, perpetuating a cycle of being [[underweight]].<ref name="Andrews" /><ref name="Norton" /><ref name="Rutstein" />