Fetal Therapy Phone: (323) 361-6074 or (800) 687-2229
Fetal Therapy Web: www.maternal-fetalhealth.com

Twin-to-Twin Transfusion Syndrome Background

Twin-twin transfusion syndrome (TTTS) is a rare condition that afflicts about 15 percent of twins that share the same placenta (monochorionic twins). The cause of TTTS is attributed to unbalanced flow of blood through vascular channels that connect the circulatory systems of each twin via the common placenta. The shunting of blood through the vascular communications leads to a net flow of blood from one twin (the donor) to the other twin (the recipient).

The donor twin develops oligohydramnios (low amniotic fluid) and poor fetal growth, while the recipient twin develops polyhydramnios (excess amniotic fluid), heart failure, and hydrops. If left untreated, the pregnancy may be lost due to lack of blood getting to the smaller twin, fluid overload and heart failure in the larger twin, and/or preterm (early) labor leading to miscarriage of the entire pregnancy.

Twin-to-Twin Transfusion Syndrome Treatment

A new treatment approach consists of using operative fetoscopy to identify the offending vessels. Laser energy is used to seal off the blood vessels that shunt blood between the fetuses. Because the vascular connections between the two fetuses are sealed, no further blood exchange between the fetuses takes place, thus eliminating the syndrome. Pregnancy outcomes after laser therapy for TTTS are as follows: approximately 94 percent of patients will have at least one fetus survive, 73 percent will have both survive, with a 5 percent risk of neurologic injury.