Single Fetal Death in Monochorionic Twin Pregnancy: Co-Twin Prognosis and Neonatal Outcome

Abstract

The incidence of single fetal death in twin pregnancy varies from 0.5% - 6.8%, leaving the surviving fetus with increased morbi-mortality. The prognosis is worse in monochorionic pregnancies. In addressing these cases it should be noted referral to tertiary center with differentiated perinatal support, induction of fetal lung maturation and termination of pregnancy if there’s loss of fetal well-being or possibility of maternal complications and suspected neurological sequelae in the surviving fetus. The risk of iatrogenic prematurity should always be weighed with the possible consequences arising from the fetus staying in a hostile uterine environment. The authors describe a case of a 32-year-old pregnant woman with monochorionic/diamniotic twin pregnancy diagnosed with death of one of the fetuses due to fetal growth restriction and velamentous insertion of the umbilical cord at 30 weeks of gestation. The couple opted for termination of pregnancy at 33 weeks after documentation of brain changes in the surviving fetus.

Conservative Management After a Single Fetal Death in a Dichorionic Diamniotic Twin Pregnancy and Fetus Papyraceus: A Case Report

“…However, it is most probably related to the presence of important vascular anastomoses that allow thrombotic substances released by the dead fetus to reach the circulation of the surviving fetus, causing hypotension, hypoperfusion, hypoxia, acidosis, exsanguination, severe anaemia, and generalised ischaemic injuries (particularly in the central nervous system of the surviving twin). 9,11,12 In monochorionic twins, the risk of prematurity (most relevant between 28-33 weeks of pregnancy), neuropsychomotor disorders, postnatal cranial imaging abnormalities, and death of the surviving twin after single fetal death were estimated at 68%, 26%, 34%, and 15%, respectively, while in dichorionic twins the rates were estimated at 54%, 2%, 16%, and 3%, respectively. 10,12 Currently, there is no consensus regarding the follow-up or definition of the ideal gestational age for interruption of pregnancy in the event of the death of one of the fetuses in twin pregnancies.…”

“…However, fetal death in the first trimester does not appear to be associated with adverse outcomes, a risk that increases from the second or third trimester. [11][12][13] In these scenarios, the conservative approach is advocated above all else when gestational loss of one of the fetuses occurs at a non-viable gestational age or is associated with extreme prematurity. 13 In the case of dichorionic pregnancies, pregnancy must be carried out for at least 38 weeks, whenever both maternal and fetal wellbeing are assured, 6,11,13 unless there is some other obstetric indication for termination of pregnancy.…”

“…[11][12][13] In these scenarios, the conservative approach is advocated above all else when gestational loss of one of the fetuses occurs at a non-viable gestational age or is associated with extreme prematurity. 13 In the case of dichorionic pregnancies, pregnancy must be carried out for at least 38 weeks, whenever both maternal and fetal wellbeing are assured, 6,11,13 unless there is some other obstetric indication for termination of pregnancy. In the case of monochorionic pregnancies, conservative management is an option, especially prior to 34 weeks, because of the greater neonatal risks associated with prematurity.…”

“…Normal umbilical artery Doppler pulsatility index carries the best prognosis. 11,13,17 For maternal monitoring, coagulation blood tests are recommended. Moreover, special attention should be paid to blood pressure and proteinuria levels.…”

Perinatal outcomes of intrauterine transfusion for the surviving twin in monochorionic twin gestation involving a single fetal demise

“…Currently, it is uncommon to recommend immediate delivery of the surviving co-twin even if the gestational age is considered viable, as this is likely to worsen the co-twin's prognosis further. [10][11][12][13][14] Therefore, conservative management and close monitoring of the surviving co-twin may be preferable.…”