Maternal outcome after open fetal surgery. A review of the first 17 human cases. A few fetal diseases may benefit from surgical treatment before birth, but hysterotomy and subsequent delivery by cesarean section pose a risk to the otherwise unaffected mother. To assess maternal risk of mortality, morbidity, and reproductive potential after fetal surgery, we reviewed our experience with 17 highly selected women who underwent fetal surgery. Fifteen of these procedures were performed for one of two congenital anomalies: severe bilateral hydronephrosis and congenital diaphragmatic hernia. There were no deaths or serious maternal injuries. In the 14 women who continued pregnancy after hysterotomy, uterine irritability and preterm labor were frequent complications, requiring early confinement in most cases. There has been no detectable effect on future fertility, as indicated by eight subsequent normal pregnancies. We conclude that hysterotomy for fetal surgery can be accomplished without unduly endangering the mother's life or her future reproductive potential. However, morbidity related to premature labor remains a serious problem, and our ability to control uterine contractions after hysterotomy remains the limiting factor in human fetal surgery. 