Monoamniotic twin pregnancies. Review of the literature, and a case report with vaginal delivery

Objective: To specify the process of the sometimes difficult diagnosis of monoamniotic twin pregnancies, as well as the best practise for delivery of this type of pregnancy. Method: Using their personal observation (a patient with a monoamniotic twin pregnancy, which presented a vaginal delivery at 35 weeks of gestation, two girls, in cephalic presentation, without particular problem, despite an entanglement of the cord and the existence of a knot), the authors established a review of the literature on this subject. Results: Monoamniotic twin pregnancies represent a rare possibility. The prognosis is traditionally somber: 40–60% mortality, mainly due to pathologies of the cord. The review of the recent literature shows that most authors remain in favour of weekly ultrasound supervision from the 23rd week and of caesarean section in principle at 34 weeks (or from fetal pulmonary maturation). Conclusion: In the absence of funicular compression signs by colour-doppler, and under the cover of flawless obstetrical conditions, vaginal delivery can only be authorized for cases when both presentations are cephalic.