Objective To establish maternal complication rates for fetoscopic or open fetal surgery. Methods We conducted a systematic literature review for studies of fetoscopic or open fetal surgery performed since 1990, recording maternal complications during fetal surgery, the remainder of pregnancy, delivery, and after the index pregnancy. Results One hundred sixty‐six studies were included, reporting outcomes for open fetal (n = 1193 patients) and fetoscopic surgery (n = 9403 patients). No maternal deaths were reported. The risk of any maternal complication in the index pregnancy was 20.9% (95%CI, 15.22‐27.13) for open fetal and 6.2% (95%CI, 4.93‐7.49) for fetoscopic surgery. For severe maternal complications (grades III to V Clavien‐Dindo classification of surgical complications), the risk was 4.5% (95% CI 3.24‐5.98) for open fetal and 1.7% (95% CI, 1.19‐2.20) for fetoscopic surgery. In subsequent pregnancies, open fetal surgery increased the risk of preterm birth but not uterine dehiscence or rupture. Nearly one quarter of reviewed studies (n = 175, 23.3%) was excluded for failing to report the presence or absence of maternal complications. Conclusions Maternal complications occur in 6.2% fetoscopic and 20.9% open fetal surgeries, with serious maternal complications in 1.7% fetoscopic and 4.5% open procedures. Reporting of maternal complications is variable. To properly quantify maternal risks, outcomes should be reported consistently across all fetal surgery studies.

Objective: To establish maternal complication rates for fetoscopic or open fetal surgery.Methods: We conducted a systematic literature review for studies of fetoscopic or open fetal surgery performed since 1990, recording maternal complications during fetal surgery, the remainder of pregnancy, delivery, and after the index pregnancy. Results: One hundred sixty-six studies were included, reporting outcomes for open fetal (n = 1193 patients) and fetoscopic surgery (n = 9403 patients). No maternal deaths were reported. The risk of any maternal complication in the index pregnancy was 20.9% (95%CI, 15.22-27.13) for open fetal and 6.2% (95%CI, 4.93-7.49) for fetoscopic surgery. For severe maternal complications (grades III to V Clavien-Dindo classification of surgical complications), the risk was 4.5% (95% CI 3.24-5.98) for open fetal and 1.7% (95% CI, 1.19-2.20) for fetoscopic surgery. In subsequent pregnancies, open fetal surgery increased the risk of preterm birth but not uterine dehiscence or rupture. Nearly one quarter of reviewed studies (n = 175, 23.3%) was excluded for failing to report the presence or absence of maternal complications. Conclusions: Maternal complications occur in 6.2% fetoscopic and 20.9% open fetal surgeries, with serious maternal complications in 1.7% fetoscopic and 4.5% open procedures.Reporting of maternal complications is variable. To properly quantify maternal risks, outcomes should be reported consistently across all fetal surgery studies. | INTRODUCTIONThe last 35 years have witnessed an expansion of fetal therapy options, 1,2 with surgery on the fetus, placenta, or cord now relatively common in tertiary-level fetal medicine units. Enabled by advancements in imaging, surgical instrumentation and techniques, early diagnosis, and treatment of fetal anomalies are now possible for a wide range of conditions. 3 The mother has been called an "innocent bystander" in fetal surgery, 4 and generally, fetal therapy is almost exclusively offered to women who are healthy themselves. Fetal surgery poses risks to the mother not only during the procedure itself but also throughout the