E-Mail karger@karger.com Original Paper Fetal Diagn Ther DOI: 10.1159/000441451 Twin Anemia-Polycythemia Sequence: Perinatal Management and Outcome Eran Ashwal Yoav Yinon Michal Fishel-Bartal Abraham Tsur Benjamin Chayen Boaz Weisz Shlomo Lipitz  Department of Obstetrics and Gynecology, Sheba Medical Center, Tel-Hashomer, and Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel alive at 1 month of age. Conclusion: The neonatal outcome of monocohorionic twins affected by TAPS is favorable and comparable to gestational age-matched uncomplicated monochorionic twins. © 2015 S. Karger AG, Basel Introduction The vascular bed architecture of the monochorionic placenta determines the potential risk of multiple gesta- tion. The primary clinical scenarios [i.e twin-to-twin transfusion syndrome (TTTS) or selective intrauterine growth restriction] are derived by the intertwin anasto- moses causing unbalanced net fetofetal blood transfusion or by imbalanced placental share. TTTS is a well-estab- lished complication with a reported incidence of 10–15% [1] of cases characterized by twin oligo-polyhydramnios sequence. Another relatively recent clinical complication is twin anemia-polycythemia sequence (TAPS). TAPS is characterized by the relatively small diameter (<1 mm) of arteriovenous (AV) anastomoses [2, 3]. TAPS can occur either spontaneously in approximately 3–5% of Key Words Twin anemia-polycythemia sequence · Intrauterine transfusion · Monochorionic twins Abstract Objective: To determine the perinatal outcome of mono- chorionic twin pregnancies complicated by twin anemia- polycythemia sequence (TAPS). Methods: All monochorion- ic twins diagnosed with TAPS between 2011 and 2014 were included. Each twin pair with TAPS (study group) was com- pared with 2 uncomplicated monochorionic twin pairs who were matched for gestational age at delivery (control group). Neonatal morbidity and mortality were evaluated. Results: During the study period, 179 monochorionic twins were fol- lowed at our center, of whom 46 underwent laser ablation due to twin-to-twin transfusion syndrome. TAPS was diag- nosed in 10 cases; 8 of them were spontaneous, and 2 oc- curred following laser surgery. Out of 7 patients diagnosed prenatally with TAPS, 5 cases were managed expectantly, and 2 cases were treated with intrauterine blood transfusion. The rates of severe and mild central nervous system lesions on postnatal ultrasound were similar in the TAPS group and control group (5.0 vs. 2.5%, p = 0.61, and 5.0 vs. 12.5%, p = 0.25, respectively). Additionally, severe neonatal morbidity was comparable between the groups. All neonates were Received: June 8, 2015 Accepted after revision: October 1, 2015 Published online: November 19, 2015 Dr. Yoav Yinon Department of Obstetrics and Gynecology, Sheba Medical Center Derech Sheba 2 Tel-Hashomer 52621 (Israel) E-Mail yoav.yinon27  @  gmail.com © 2015 S. Karger AG, Basel 1015–3837/15/0000–0000$39.50/0 www.karger.com/fdt Eran Ashwal and Yoav Yinon contributed equally to this work. Downloaded by: Univ. of California San Diego 198.143.33.33 - 4/12/2016 12:37:07 PM