Normalization of amniotic fluid levels after fetoscopic laser surgery for twin-twin transfusion syndrome.

Objective: The purpose of this study was to describe amniotic fluid (AF) normalization after laser surgery for twin-twin transfusion syndrome (TTTS).

Methods: Patients with TTTS (n = 174) who had laser surgery from 2006 through 2009 underwent serial measurements of the AF maximum vertical pockets (MVPs) during postoperative weeks 1 through 10. A normal MVP was defined as greater than 2 cm and less than 8 cm.

Discordant blood chimerism in dizygotic monochorionic laser-treated twin-twin transfusion syndrome.

Background: Twin-twin transfusion syndrome occurs in 10% of monozygotic monochorionic twin gestations and results from an unbalanced exchange of blood from the donor to the recipient fetus through placental anastomoses.

Case: We present a case of twin-twin transfusion syndrome with differing fetal sex treated with in utero laser surgery. Genetic analyses showed 46,XX/46,XY hematologic chimerism in both twins at birth and at 6 months, with the recipient twin being significantly more chimeric than the donor.

Spontaneous twin anemia-polycythemia sequence complicated by recipient placental vascular thrombosis and hydrops fetalis.

Twin anemia-polycythemia sequence (TAPS) is an atypical form of twin-twin transfusion syndrome (TTTS) that presents as a large intertwin hemoglobin difference with one twin developing anemia and the other developing polycythemia, without oligohydramnios-polyhydramnios sequence (Lopriore et al., Placenta 2007;28:47-51). The prenatal diagnostic criteria for TAPS require that the middle cerebral artery-peak systolic velocity (MCA-PSV) measure greater than 1.

Amniopatch as a treatment for rupture of membranes following laser surgery for twin-twin transfusion syndrome.

Objective: The risk of iatrogenic rupture of membranes (IROM) is 5-30% after operative fetoscopy. The aim of this study was to describe outcomes of patients with IROM following selective laser photocoagulation of communicating vessels (SLPCV) for twin-twin transfusion syndrome (TTTS) who were subsequently treated with amniopatch therapy.

Methods: A review of patients who underwent treatment for mid-trimester TTTS between March 2006 and February 2008 with IROM within 7 days of SLPCV was performed.