Minimally Invasive Laser Surgery Improves Odds for Serious Complication of Identical Twin Pregnancy

As the number of women having twins has increased, so has the odds of developing a serious pregnancy complication called twin-to-twin transfusion syndrome (TTTS). This disorder affects as many as 15 percent of identical twin pregnancies, and results in uneven blood flow between the fetuses. Until recently the outcome was usually death or disabilities for the surviving babies.

Now a new minimally invasive laser treatment has improved the odds. Available at NewYork-Presbyterian Morgan Stanley Children's Hospital - one of only 10 centers to offer it, and the only one in New York - the procedure involves coagulating unnecessary and harmful blood connections between the two fetuses.

"This laser treatment has saved the lives of many twins with TTTS, giving them the chance to grow up healthy and strong," says Dr. Lynn Simpson, medical director of the Center for Prenatal Pediatrics at NewYork-Presbyterian Morgan Stanley Children's Hospital and associate professor of clinical obstetrics and gynecology at Columbia University College of Physicians and Surgeons. "The laser approach is straightforward and safe. And while it isn't always successful, it is a major improvement over the traditional approach of draining the mother's amniotic fluid."

Studies show that in about 90 percent of laser cases, one twin will survive, and in 70 percent of cases, both will. The traditional approach has a survival rate of only 66 percent for a single fetus. Normal brain development is also more likely in babies treated with the laser procedure.

Since Morgan Stanley Children's Hospital began offering laser treatment in July, all TTTS cases meeting criteria for coagulation therapy have been treated using the laser.

The hour-long procedure is performed under local or regional anesthesia and uses a tiny scope that carries the laser wire and a camera though the mother's abdomen and into her uterus. While it can be done on an outpatient basis, mothers are usually kept overnight for observation.

Twin-to-Twin Transfusion Syndrome

In identical twin pregnancies with TTTS, the fetal blood supply is abnormally connected within a shared placenta. Although each fetus uses its own portion of the placenta, the connecting vessels allow blood to pass from one twin to the other. Depending on the number, type and direction of the interconnecting blood vessels, blood can be transferred disproportionately from one twin (the "donor") to the other (the "recipient"). This causes the donor twin to have decreased blood volume, retarding its development and growth, while the larger recipient is at risk of heart failure due to an overworked heart. In rare cases, the condition can happen with triplets or higher multiples, when a pair of fetuses shares one placenta. If untreated early in pregnancy, in 80 to 90 percent of cases, both twins will die. The condition is usually diagnosed during the second trimester with a routine ultrasound.