This is the ‘most widely available therapy’ and involves draining the excess amniotic fluid (polyhydramnios) by inserting a needle into the amniotic sac of the recipient. It relieves the mother’s abdominal discomfort, and prolongs TTTS pregnancies by reducing the risk of spontaneous rupture of the membranes or premature labor from the enlarged uterus. In addition, by reducing the pressure inside the womb, it has been reported to change the nature of the transfusion in some TTTS cases. Survival rates with amniocenteses approach 80% in some centers, but health status of surviving infants are not always reported. Recent reports (see section of Medical Research and Articles) indicate a 60-75% survival rate with amniocentesis, but 10-30% of the survivors have had neurological (brain) abnormalities when ultrasounds were performed in the nursery. Since the babies remain connected, there is the continuing transfusion process between the twins (both chronic and acute). This may explain the higher rate of medical problems in the surviving babies than methods that disconnect the babies.
This is the intentional creation of a hole in the membrane septum between the babies’ bags of water with a needle during ultrasound scanning. It allows for some of the excess amniotic fluid in the recipient’s bag of water to enter the sac of the donor who usually has no to very little amniotic fluid. In one report of 12 TTTS cases, the septostomy to delivery interval was 8.5 weeks and 83% (20/214) of the twins survived. The health of the surviving twins was not given. The babies remain connected with this, and there is now the additional risks associated with twins who sit in the same sac (monoamnionic) such as possible umbilical cord entanglement.