ObjectiveThe published literature mostly reports outcomes of twin pregnancies complicated by twin–twin transfusion syndrome (TTTS) without differentiating whether the pregnancy is also complicated by another pathology, such as selective fetal growth restriction (sFGR). The aim of this systematic review was to report the outcomes of monochorionic twin pregnancies undergoing laser surgery for TTTS complicated compared to those not complicated by the coexistence of sFGR.MethodsMedline, Embase and Cochrane databases were searched. The inclusion criteria were monochorionic diamniotic (MCDA) twin pregnancies with TTTS that are also complicated, compared to those non‐complicated by sFGR, undergoing laser therapy. The primary outcome was the overall fetal loss following laser surgery, defined as miscarriage and intra‐uterine death. The secondary outcomes included fetal loss within 24 h from laser surgery, survival at birth, preterm birth (PTB) prior to 32 weeks, PTB prior to 28 weeks of gestation, composite perinatal morbidity, neurological and respiratory morbidity, and survival free from neurological impairment. All these outcomes were explored in the overall population of twin pregnancies complicated compared to those not complicated by sFGR in the setting of TTTS, and in the donor and recipient twin separately. Random‐effect meta‐analyses were used to combine data and the results reported as pooled odd ratios (ORs) with their 95% confidence intervals (CIs).ResultsSix studies (1710 MCDA twin pregnancies) were included. The overall risk of fetal loss after laser surgery was significantly higher in MCDA twin pregnancies with TTTS complicated by sFGR (20.6% vs 14.56%) with an OR of 1.52, 95% CI 1.3‐1.9 (p<0.001). The risk of fetal loss was significantly higher for the donor but not for the recipient twin. The rate of alive twins was 79.4% (95% CI 73.3‐84.9%) in pregnancies complicated by TTTS with and 85.5% (95% CI 80.9‐89.6%) with no sFGR (pooled OR 0.66, 95% CI 0.5‐0.8; p<0.001). There was no significant difference in the risk of PTB prior to 32 (p=0.308) and prior to 28 weeks (p=0.310). Assessment of short‐ and long‐term perinatal morbidity was affected by the very small number of cases. There was no significant difference in the risk of composite (p=0.5189) or respiratory morbidity (p=0.531) between twins complicated by TTTS with compared to those without sFGR, while the risk of neurologic morbidity in the donor (OR 2.39, 95% CI 1.1‐5.2; p=0.029) but not in the recipient (p=0.361) twin was significantly higher in those with TTTS and sFGR. Survival free from neurological impairment was observed in 70.8% (95% CI 44.9‐91.0%) of twin pregnancies with TTTS complicate and in 75.8% (95% CI 51.9‐93.3%) of those not complicated by sFGR with no difference between the two groups.ConclusionssFGR coexisting with TTTS represents an additional risk factor for fetal loss following laser surgery. The findings of this meta‐analysis should be useful in individualized risk assessment of twin pregnancies complicated by TTTS and tailored counseling of the parents prior to laser surgery.This article is protected by copyright. All rights reserved.