Editing Twin-to-twin transfusion syndrome (section)

==Treatment==
Various treatments exist for TTTS.

===Non treatment===
This is equivalent of zero intervention. It has been associated with almost 100% mortality rate of one or all fetuses. Exceptions to this include patients that are still in Stage 1 TTTS and are past 22 weeks' gestation.{{citation needed|date=December 2021}}

===Adjustment of amniotic fluid===

====Serial amniocentesis====

This procedure involves removal of amniotic fluid periodically throughout the pregnancy under the assumption that the extra fluid in the recipient twin can cause preterm labor, perinatal mortality, or tissue damage. In the case that the fluid does not reaccumulate, the reduction of amniotic fluid stabilizes the pregnancy. Otherwise, the treatment is repeated as necessary. There is no standard procedure for how much fluid is removed each time. There is a danger that if too much fluid is removed, the recipient twin could die. This procedure is associated with a 66% survival rate of at least one fetus, with a 15% risk of cerebral palsy, and average delivery occurring at 29 weeks' gestation.{{citation needed|date=December 2021}}

====Septostomy, or iatrogenic disruption of the dividing membrane====

This procedure involves the tearing of the dividing membrane between fetuses such that the amniotic fluid of both twins mixes, under the assumption that pressure is different in either amniotic sac and that its equilibration will ameliorate progression of the disease. It has not been proven that pressures are different in either amniotic sac. Use of this procedure can preclude use of other procedures as well as make difficult the monitoring of disease progression. In addition, tearing the dividing membrane has contributed to cord entanglement and demise of fetuses through physical complications.{{citation needed|date=December 2021}}

===Adjustment of blood supply===

==== Laser therapy (fetoscopic laser photocoagulation) ====
[[File:TTTS laser cartoon.JPG|thumb|Illustration of a [[fetoscopy]] and laser ablation of connecting vessels in twin-to-twin transfusion syndrome]]

This procedure involves [[endoscopic surgery]] using laser to interrupt the vessels that allow exchange of blood between fetuses under the assumption that the unequal sharing of blood through these vascular communications leads to unequal levels of amniotic fluid. Each fetus remains connected to its primary source of blood and nutrition, the placenta, through the umbilical cord. This procedure is conducted once, with the exception of all vessels not having been found. The use of endoscopic instruments allows for short recovery time. This procedure has been associated with 85% survival rate of at least one fetus, with a 6–7% risk of cerebral palsy and average delivery occurring at 32–33 weeks' gestation.<ref name="Benoit RM 2014"/>

[[Twin anemia–polycythemia sequence]] (TAPS) may occur after laser surgery for TTTS (post-laser form). The spontaneous form of TAPS complicates approximately 3–5% of monochorionic twin pregnancies, whereas the post-laser form occurs in 2–13% of TTTS cases.<ref>Robyr R, Lewi L, Salomon LJ, Yamamoto M, Bernard JP, Deprest J et al. Prevalence and management of late fetal complications following successful selective laser coagulation of chorionic plate anastomoses in twin-to-twin transfusion syndrome. Am J Obstet Gynecol 2006; 194(3):796-803.</ref><ref>Habli M, Bombrys A, Lewis D, Lim FY, Polzin W, Maxwell R et al. Incidence of complications in twin-twin transfusion syndrome after selective fetoscopic laser photocoagulation: a single-center experience. Am J Obstet Gynecol 2009; 201(4):417.</ref> The pathogenesis of TAPS is based on the presence of few, minuscule arterio-venous (AV) placental anastomoses (diameter <1mm)<ref>Lopriore E, Deprest J, Slaghekke F, Oepkes D, Middeldorp JM, Vandenbussche FP et al. Placental characteristics in monochorionic twins with and without twin anemia-polycythemia sequence. Obstet Gynecol 2008; 112(4):753-758.</ref> allowing a slow transfusion of blood from the donor to the recipient and leading gradually to highly discordant Hb levels.<ref>Slaghekke F, Kist WJ, Oepkes D, Pasman SA, Middeldorp JM, Klumper FJ et al. Twin anemia-polycythemia sequence: diagnostic criteria, classification, perinatal management and outcome. Fetal Diagn Ther 2010; 27(4):181-190.</ref>

A 2014 review found that laser coagulation resulted in fewer fetal and perinatal deaths than amnioreduction and septostomy, and recommended its use for all states of TTTS.<ref name=":1">Roberts D, Neilson JP, Kilby M, Gates S. (2014) Interventions for the treatment of twin–twin transfusion syndrome. Cochrane Database Syst Rev</ref>

=== Selective reduction ===
[[Selective reduction|Selective termination]] of one of the fetuses is usually not considered until TTFS has reached either stage III or IV,<ref name=":5">{{Citation |last=Borse |first=Vyvian |title=Twin-to-Twin Transfusion Syndrome |date=2024 |work=StatPearls |url=http://www.ncbi.nlm.nih.gov/books/NBK563133/ |access-date=2024-02-21 |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=33085280 |last2=Shanks |first2=Anthony L.}}</ref> and is indicated when the death of one twin is imminent, but the fetus is too premature to deliver, as the death of one twin will cause the death of the second twin due to the shared blood supply if not immediately delivered.<ref name=":5" />

One procedure for selective reduction is '''umbilical cord occlusion'''. This procedure involves the ligation or otherwise occlusion of one twin's umbilical cord to interrupt the exchange of blood between the fetuses. The procedure is typically offered in cases where one of the fetuses is presumed moribund and endangering the life or health of the other twin through resultant hypotension.<ref>{{cite journal |last1=Rossi |first1=A Cristina |date=1 September 2012 |title=Treatment of twin–twin transfusion syndrome |journal=Expert Review of Obstetrics & Gynecology |volume=7 |issue=5 |pages=477–482 |doi=10.1586/eog.12.45 |doi-access=free}}</ref> Use of this treatment has decreased as TTTS is identified and treated in earlier stages and with better outcomes. When used, it is associated with an 85% survival rate of the remaining fetuses with 5% risk of cerebral palsy and a 33–39 weeks of gestation at delivery.<ref>{{Cite journal |last1=Nakata |first1=M. |last2=Chmait |first2=R. H. |last3=Quintero |first3=R. A. |date=May 2004 |title=Umbilical cord occlusion of the donor versus recipient fetus in twin-twin transfusion syndrome: Cord occlusion in TTTS |journal=Ultrasound in Obstetrics and Gynecology |volume=23 |issue=5 |pages=446–450 |doi=10.1002/uog.1034 |pmid=15133793 |s2cid=25531930}}</ref><ref>{{Cite journal |last1=Taylor |first1=M. J. O. |last2=Shalev |first2=E. |last3=Tanawattanacharoen |first3=S. |last4=Jolly |first4=M. |last5=Kumar |first5=S. |last6=Weiner |first6=E. |last7=Cox |first7=P. M. |last8=Fisk |first8=N. M |date=January 2001 |title=Ultrasound-guided umbilical cord occlusion using bipolar diathermy for Stage III/IV twin-twin transfusion syndrome |journal=Prenatal Diagnosis |volume=22 |issue=1 |pages=70–76 |doi=10.1002/pd.256 |pmid=11810656 |s2cid=19469579}}</ref>

=== Voluntary termination ===
Some women choose to have an [[abortion]] of both fetuses as the health of both fetuses is impacted by TTFS.<ref name=":5" />