OBJECTIVES: The introduction of fetoscopic laser surgery of placental anastomoses has led to a significant improvement of perinatal outcome of twin pregnancies affected by twin-to-twin-transfusion syndrome (TTTS). To quantify the perinatal outcome and neurological morbidity in triplet pregnancies complicated by TTTS, which were treated with fetoscopic laser surgery. SEARCH STRATEGY: Medline, Embase, Cinahl and Cochrane were searched. SELECTION CRITERIA: The outcomes observed were: fetal and perinatal survival, preterm birth and abnormal neurological outcome. DATA COLLECTION AND ANALYSIS: Two authors reviewed all abstracts independently. Meta-analyses of proportions were used to combine data. MAIN RESULTS: Eight studies (126 triplet pregnancies, 104 dichorionic-triamniotic [DCTA] and 22 monochorionic-triamniotic [MCTA]) treated with fetoscopic laser surgery were included in this review. In DCTA and MCTA pregnancies, fetal losses were 18.9% and 28.9%, respectively; perinatal losses were 23.6% and 75.0%; preterm births <28 weeks of gestation were 16.9% and 37.1%; preterm births <32 weeks of gestation were 50.0% and 69.5%; at least one fetus survived in 95.4% and 88.9% of the pregnancies; at least two fetuses survived in 81.8% and 68.3% of the pregnancies; and in 55.9% and 48.4% pregnancies all triplets survived. Finally, the incidence of abnormal neurological outcomes ranged from 0 to 37% in DCTA and from 0 to 50% in MCTA triplets. CONCLUSIONS: Both DTCA and MCTA triplet pregnancies affected by TTTS are at high risk of adverse perinatal outcome.