Pseudomonoamniotic twins with cord entanglement following genetic funipuncture

Amniocentesis was performed twice on a twin gestation, and twice there was cell growth failure in one of the twins. Therefore, funipuncture was attempted at 24 weeks. The anatomical relationship and position of the fetuses, placental cord insertion, and membranous septum dictated needle entry into the cord of the lower left fetus through the sac of the upper right fetus and the septum. The procedure was uneventful and the pregnancy was carried to 39 weeks. However, the septum between the twins had been disrupted, creating a pseudomonoamniotic pregnancy. This was noticed only after delivery of the first fetus, when it was found that the two umbilical cords were entangled. We believe that, whenever possible, puncture of the membrane between twins should be avoided. Should puncture be necessary, the possibility of pseudomonoamniotic twins must be considered.