Editing Birth defect (section)

== Epidemiology ==
[[File:Congenital anomalies world map-Deaths per million persons-WHO2012.svg|thumb|upright=1.2|Congenital anomalies deaths per million persons in 2012: {{Div col|small=yes|colwidth=10em}}{{legend|#ffff20|0–26}}{{legend|#ffe820|27–34}}{{legend|#ffd820|35–46}}{{legend|#ffc020|47–72}}{{legend|#ffa020|73–91}}{{legend|#ff9a20|92–111}}{{legend|#f08015|112–134}}{{legend|#e06815|135–155}}{{legend|#d85010|156–176}}{{legend|#d02010|177–396}}{{div col end}}]]
[[File:Congenital anomalies world map - DALY - WHO2004.svg|thumb|upright=1.2|[[Disability-adjusted life year]] for congenital anomalies per 100,000 inhabitants in 2004:<ref>{{cite web |url=https://www.who.int/healthinfo/global_burden_disease/estimates_country/en/index.html |title=WHO Disease and injury country estimates |year=2009 |work=World Health Organization |access-date=Nov 11, 2009 |archive-date=November 11, 2009 |archive-url=https://web.archive.org/web/20091111101009/http://www.who.int/healthinfo/global_burden_disease/estimates_country/en/index.html |url-status=live }}</ref>{{Div col|small=yes|colwidth=10em}}
{{legend|#b3b3b3|no data}}
{{legend|#ffff65|less than 160}}
{{legend|#fff200|160–240}}
{{legend|#ffdc00|240–320}}
{{legend|#ffc600|320–400}}
{{legend|#ffb000|400–480}}
{{legend|#ff9a00|480–560}}
{{legend|#ff8400|560–640}}
{{legend|#ff6e00|640–720}}
{{legend|#ff5800|720–800}}
{{legend|#ff4200|800–900}}
{{legend|#ff2c00|900–950}}
{{legend|#cb0000|more than 950}}
{{div col end}}]]

Congenital anomalies resulted in about 632,000 deaths per year in 2013 down from 751,000 in 1990.<ref name=GBD204 /> The types with the greatest death are [[congenital heart defect]]s (323,000), followed by [[neural tube defects]] (69,000).<ref name=GBD204 />

Many studies have found that the frequency of occurrence of certain congenital malformations depends on the sex of the child (table).<ref>{{Cite journal|pmc=1254713|pages= 286–294|year= 1964|last1= Gittelsohn|first1= A|title= Statistical Study of Twins—Methods|journal= American Journal of Public Health and the Nation's Health|volume= 54|issue= 2|last2= Milham|first2= S|doi=10.2105/ajph.54.2.286|pmid=14115496}}</ref><ref>{{Cite journal|pmid=717306|pages= 970–972|year= 1978|last1= Fernando|first1= J|title= Sex liability to single structural defects|journal= American Journal of Diseases of Children|volume= 132|issue= 10|last2= Arena|first2= P|last3= Smith|first3= D. W.|doi= 10.1001/archpedi.1978.02120350034004}}</ref><ref>{{Cite journal|pmid=9096746|pages= 225–228|year= 1997|last1= Lubinsky|first1= M. S.|title= Classifying sex biased congenital anomalies|journal= American Journal of Medical Genetics|volume= 69|issue= 3|doi= 10.1002/(SICI)1096-8628(19970331)69:3<225::AID-AJMG1>3.0.CO;2-K}}</ref><ref>{{cite journal|pmid=11745830|pages=237–251|year=2001|last1=Lary|first1=J. M.|title=Sex differences in the prevalence of human birth defects: A population-based study|journal=Teratology|volume=64|issue=5|last2=Paulozzi|first2=L. J.|doi=10.1002/tera.1070}}</ref><ref name="Cui">{{cite journal|pmid=16265641|pages= 876–880|year= 2005|last1= Cui|first1= W|title= Sex differences in birth defects: A study of opposite-sex twins|journal= Birth Defects Research Part A: Clinical and Molecular Teratology|volume= 73|issue= 11|last2= Ma|first2= C. X.|last3= Tang|first3= Y|last4= Chang|first4= V|last5= Rao|first5= P. V.|last6= Ariet|first6= M|last7= Resnick|first7= M. B.|last8= Roth|first8= J|doi= 10.1002/bdra.20196}}</ref> For example, pyloric stenosis occurs more often in males while congenital hip dislocation is four to five times more likely to occur in females. Among children with one kidney, there are approximately twice as many males, whereas among children with three kidneys there are approximately 2.5 times more females. The same pattern is observed among infants with excessive number of ribs, vertebrae, teeth and other organs which in a process of evolution have undergone reduction—among them there are more females. Contrarily, among the infants with their scarcity, there are more males. Anencephaly is shown to occur approximately twice as frequently in females.<ref name="WHO reports">World Health Organization reports. "Congenital malformations", Geneve, 1966, p. 128.</ref> The number of boys born with 6 fingers is two times higher than the number of girls.<ref>Darwin C. (1871) The descent of man and selection in relation to sex. London, John Murray, 1st ed.</ref> Now various techniques are available to detect congenital anomalies in fetus before birth.<ref>{{Cite news|url=https://www.cdc.gov/ncbddd/birthdefects/diagnosis.html|title=Diagnosis {{!}} Birth Defects {{!}} NCBDDD {{!}} CDC|date=2017-12-04|work=Centers for Disease Control and Prevention|access-date=2018-11-07|language=en-us|archive-date=2018-11-07|archive-url=https://web.archive.org/web/20181107224830/https://www.cdc.gov/ncbddd/birthdefects/diagnosis.html|url-status=live}}</ref>

About 3% of newborns have a "major physical anomaly", meaning a physical anomaly that has cosmetic or functional significance.<ref>Kumar, Abbas and Fausto, eds., ''Robbins and Cotran's Pathologic Basis of Disease, 7th edition'', p.470.</ref>
Physical congenital abnormalities are the leading cause of infant mortality in the United States, accounting for more than 20% of all infant deaths. Seven to ten percent of all children{{clarify|reason=Of literally "all" children or just "all" of the 3% above?|date=November 2014}} will require extensive medical care to diagnose or treat a birth defect.<ref name="pmid2468064">{{cite journal |author=Dicke JM |title=Teratology: principles and practice |journal=Med. Clin. North Am. |volume=73 |issue=3 |pages=567–82 |year=1989 |pmid=2468064 |doi=10.1016/S0025-7125(16)30658-7}}</ref>

:{| class="wikitable"
|+ '''The sex ratio of patients with congenital malformations'''
! Congenital anomaly !! Sex ratio, ♂♂:♀♀
|-
| '''Defects with female predominance''' ||
|-
| Congenital hip dislocation || 1 ''':''' 5.2;<ref name="Rajewski" /> 1 ''':''' 5;<ref name="Montagu">Montagu A. (1968) Natural Superiority of Women, The, Altamira Press, 1999.</ref> 1 ''':''' 8;<ref name="Cui" /> 1 ''':''' 3.7<ref name="Riley, Halliday">Riley M., Halliday J. (2002) Birth Defects in Victoria 1999–2000, Melbourne.</ref>
|-
| [[Cleft lip and palate|Cleft palate]] || 1 ''':''' 3<ref name="Montagu" />
|-
| [[Anencephaly]] || 1 ''':''' 1.9;<ref name="Rajewski" /> 1 ''':''' 2<ref name="WHO reports" />
|-
| Craniocele || 1 ''':''' 1.8<ref name="Rajewski" />
|-
| Aplasia of lung || 1 ''':''' 1.51<ref name="Rajewski" />
|-
| Spinal herniation || 1 ''':''' 1.4<ref name="Rajewski" />
|-
| Diverticulum of the esophagus || 1 ''':''' 1.4<ref name="Rajewski" />
|-
| Stomach || 1 ''':''' 1.4<ref name="Rajewski" />
|-
| '''Neutral defects''' ||
|-
| Hypoplasia of the tibia and femur || 1 ''':''' 1.2<ref name="Rajewski" />
|-
| [[Spina bifida]] || 1 ''':''' 1.2<ref name="Riley, Halliday" />
|-
| Atresia of small intestine || 1 ''':''' 1<ref name="Rajewski" />
|-
| [[Microcephaly]] || 1.2 ''':''' 1<ref name="Riley, Halliday" />
|-
| [[Esophageal atresia]] || 1.3 ''':''' 1;<ref name="Rajewski" /> 1.5 ''':''' 1<ref name="Riley, Halliday" />
|-
| [[Hydrocephalus]] || 1.3 ''':''' 1<ref name="Riley, Halliday" />
|-
| '''Defects with male predominance''' ||
|-
| Diverticula of the colon || 1.5 ''':''' 1<ref name="Rajewski" />
|-
| Atresia of the rectum || 1.5 ''':''' 1;<ref name="Rajewski" /> 2 ''':''' 1<ref name="Riley, Halliday" />
|-
| Unilateral [[renal agenesis]] || 2 ''':''' 1;<ref name="Rajewski" /> 2.1 ''':''' 1<ref name="Riley, Halliday" />
|-
| Schistocystis || 2 ''':''' 1<ref name="Rajewski" />
|-
| [[Cleft lip and palate]] || 2 ''':''' 1;<ref name="Montagu" /> 1.47 ''':''' 1<ref name="Riley, Halliday" />
|-
| Bilateral [[renal agenesis]] || 2.6 ''':''' 1<ref name="Rajewski" />
|-
| Congenital anomalies of the genitourinary system || 2.7 ''':''' 1<ref name="Cui" />
|-
| [[Pyloric stenosis]], congenital || 5 ''':''' 1;<ref name="Montagu" /> 5.4 ''':''' 1<ref name="Cui" />
|-
| [[Meckel's diverticulum]] || More common in boys<ref name="Rajewski" />
|-
| [[Congenital megacolon]] || More common in boys<ref name="Rajewski" />
|-
| '''All defects''' || 1.22 ''':''' 1;<ref>{{Cite journal|pmid=14745913|pages=953–958|year=2003|last1=Shaw|first1=G. M.|title=Differential risks to males and females for congenital malformations among 2.5 million California births, 1989–1997|journal=Birth Defects Research Part A: Clinical and Molecular Teratology|volume=67|issue=12|last2=Carmichael|first2=S. L.|last3=Kaidarova|first3=Z|last4=Harris|first4=J. A.|doi=10.1002/bdra.10129}}</ref> '''1.29 : 1'''<ref name="Cui" />
|}
* Data<ref name="Cui" /> obtained on opposite-sex twins. ** — Data<ref name="Riley, Halliday" /> were obtained in the period 1983–1994.

P. M. Rajewski and A. L. Sherman (1976) have analyzed the frequency of congenital anomalies in relation to the system of the organism. Prevalence of men was recorded for the anomalies of phylogenetically younger organs and systems.<ref name="Rajewski">Rajewski P. M., Sherman A. L. (1976) The importance of gender in the epidemiology of malignant tumors (systemic-evolutionary approach). In: Mathematical treatment of medical-biological information. M., Nauka, p. 170–181.</ref>

In respect of an etiology, sexual distinctions can be divided on appearing before and after differentiation of male's gonads during embryonic development, which begins from the eighteenth week. The testosterone level in male embryos thus raises considerably.<ref>{{cite journal|pmid=4856555|pages= 612–617|year= 1974|last1= Reyes|first1= F. I.|title= Studies on human sexual development. II. Fetal and maternal serum gonadotropin and sex steroid concentrations|journal= The Journal of Clinical Endocrinology & Metabolism|volume= 38|issue= 4|last2= Boroditsky|first2= R. S.|last3= Winter|first3= J. S.|last4= Faiman|first4= C|doi= 10.1210/jcem-38-4-612}}</ref> The subsequent hormonal and physiological distinctions of male and female embryos can explain some sexual differences in frequency of congenital defects.<ref>{{Cite web|date=2021-01-31|title=Birth Defects: Saving Pediatric Patients from Congenital Defects|url=https://mdforlives.blog/2021/01/31/birth-defects-preventable/|access-date=2021-02-09|website=MDforLives|language=en-US|archive-date=2021-02-13|archive-url=https://web.archive.org/web/20210213003823/https://mdforlives.blog/2021/01/31/birth-defects-preventable/|url-status=live}}</ref> It is difficult to explain the observed differences in the frequency of birth defects between the sexes by the details of the reproductive functions or the influence of environmental and social factors.{{citation needed|date=December 2024}}

=== United States ===
The CDC and National Birth Defect Project studied the incidence of birth defects in the US. Key findings include:{{citation needed|date=December 2024}}
* Down syndrome was the most common condition with an estimated prevalence of 14.47 per 10,000 live births, implying about 6,000 diagnoses each year.
* About 7,000 babies are born with a cleft palate, cleft lip or both.

{| class="wikitable"
|+Adjusted National Prevalence Estimates and Estimated Number of Cases in the United States, 2004–2006<ref>{{Cite web|url = https://www.cdc.gov/ncbddd/birthdefects/features/birthdefects-keyfindings.html|title = Key Findings: Updated National Birth Prevalence Estimates for Selected Birth Defects in the United States, 2004–2006|access-date = October 1, 2014|website = CDC|publisher = Centers for Disease Control and Prevention (CDC) and the National Birth Defects Prevention Network|archive-date = October 28, 2014|archive-url = https://web.archive.org/web/20141028181420/http://www.cdc.gov/ncbddd/birthdefects/features/birthdefects-keyfindings.html|url-status = live}}</ref>
!Birth Defects !! Cases per Births !! Estimated Annual Number of Cases !! Estimated National Prevalence per 10,000 Live Births (Adjusted for maternal race/ethnicity)
|-
| colspan="4" |'''Central nervous system defects'''
|-
| [[Anencephaly]]||1 in 4,859||859||2.06
|-
| [[Spina bifida]] without anencephaly||1 in 2,858||1460||3.50
|-
| [[Encephalocele]]||1 in 12,235||341||0.82
|-
| colspan="4" | '''Eye defects'''
|-
| [[Anophthalmia]]/ [[microphthalmia]]||1 in 5,349||780||1.87
|-
| colspan="4" |'''Cardiovascular defects'''
|-
| Common truncus||1 in 13,876||301||0.72
|-
| Transposition of great arteries||1 in 3,333||1252||3.00
|-
| [[Tetralogy of Fallot]]||1 in 2,518||1657||3.97
|-
| [[Atrioventricular septal defect]]||1 in 2,122||1966||4.71
|-
| [[Hypoplastic left heart syndrome]]||1 in 4,344||960||2.30
|-
| colspan="4" |'''Orofacial defects'''
|-
| [[Cleft palate]] without cleft lip||1 in 1,574||2651||6.35
|-
| [[Cleft lip]] with and without cleft palate||1 in 940||4437||10.63
|-
| colspan="4" |'''Gastrointestinal defects'''
|-
| [[Esophageal atresia]]/tracheoeophageal fistula||1 in 4,608||905||2.17
|-
| Rectal and large intestinalatresia/[[stenosis]]||1 in 2,138||1952||4.68
|-
| colspan="4" | '''Musculoskeletal defects'''
|-
| [[Clubfoot]], lower limbs||1 in 250 ~ 1000||...||...
|-
| Reduction deformity, upper limbs||1 in 2,869||1454||3.49
|-
| Reduction deformity, lower limbs||1 in 5,949||701||1.68
|-
| [[Gastroschisis]]||1 in 2,229||1871||4.49
|-
| [[Omphalocele]]||1 in 5,386||775||1.86
|-
| [[Diaphragmatic hernia]]||1 in 3,836||1088||2.61
|-
| colspan="4" |'''Chromosomal anomalies'''
|-
| [[Trisomy 13]]||1 in 7,906||528||1.26
|-
| [[Trisomy 21]] ([[Down syndrome]])||1 in 691||6037||14.47
|-
| [[Trisomy 18]]||1 in 3,762||1109||2.66
|}