Twin-To-Twin Transfusion Syndrome

Because TTTS is a progressive disorder, early treatment may prevent complications such as preterm labor and premature rupture of membranes due to excessive amniotic fluid. Treatment depends on the severity of the TTTS and the stage of the pregnancy.

Fetoscopic Laser Intervention

All patients with stage II, III or IV TTTS, as well as some patients with stage I TTTS, should learn about and consider fetal intervention. In most cases, the optimal treatment is fetoscopic laser intervention. The UCSF Fetal Treatment Center was one of the first in the world to perform fetoscopic laser intervention to treat TTTS. At UCSF, survival rates for at least one twin are greater than 85 percent, and about 60 percent for both twins with this procedure.

The procedure is performed by inserting a thin, fiber-optic scope through the mother's abdominal wall, through the wall of the uterus and into the amniotic cavity of the recipient twin. By examining the blood vessels on the placental surface directly with the scope, the abnormal vascular connections between the twins can be found and eliminated with a laser beam. Only those vessels that go from one twin to the other are coagulated by the laser beam. The normal blood vessels that help nourish each twin are left intact.

Before the procedure, the team performs a detailed ultrasound examination to search for the sites where the umbilical cords attach to the shared placenta and for abnormal inter-twin connections, making it quicker and easier to identify them with the fetoscope. After the laser procedure is complete, an amnioreduction — removal of extra amniotic fluid — is performed, to decrease the risk of early labor and help make the pregnancy more comfortable.

Amnioreduction Versus Fetoscopic Laser Intervention

Many families ask whether amnioreduction — removal of excess amniotic fluid — is a potential treatment option for TTTS.

Some of our most expert European colleagues attempted to address the question of whether laser intervention or amnioreduction was the best therapy for TTTS. In a randomized prospective trial, they found 76 percent survival of at least one fetus and 36 percent survival of both twins with laser intervention, compared with 51 percent survival of at least one fetus and 26 percent survival of both twins with amnioreduction. For many researchers and experts in this field, this study showed that laser was the preferred therapy for TTTS.

At our center, however, we have found a group of patients with early TTTS that respond well to amnioreduction, a less invasive therapy. In a small percentage of TTTS pregnancies, an artery-to-artery connection between the twins on the surface of the placenta can be found using ultrasound. These twins have been shown to have better outcomes overall — in our experience, more than 80 percent survival rates for both twins — after being treated with amnioreduction. Thus, although laser intervention is the appropriate therapy for the vast majority of patients with TTTS, we occasionally offer amnioreduction to patients with TTTS who meet criteria for this therapy.

Reviewed by health care specialists at UCSF Benioff Children's Hospital.

Related Information

UCSF Clinics & Centers

Fetal Treatment Center
1855 Fourth St., Second Floor, Room A-2432
San Francisco, CA 94158
Phone: (800) 793-3887
Fax: (415) 502-0660
Appointment information

Intensive Care Nursery
1975 Fourth St., Third Floor
San Francisco, CA 94158
Phone: (415) 353-1565
Fax: (415) 353-1202

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