Maternal safety and future reproduction potential are paramount considerations in fetal surgery. In a series of 102 fetal surgical procedures on time-dated pregnant monkeys, we examined the maternal complications, the potential for future pregnancy, and the effects of uterine staples used for hysterotomy and uterine closure. There were significant maternal complications associated with the development of the present techniques for fetal surgery including 3 maternal deaths, 5 uterine ruptures, and 5 cases of wound infection of dehiscence. All were preventable with knowledge gained from this experience. Compared with a control unoperated breeding colony, fetal surgery did not interfere with subsequent reproductive capacity in animals that had uterine closure with absorbable sutures. However, metal staple hysterotomy resulted in a markedly decreased fertility rate probably related to exposure of the endometrial cavity to a permanent foreign body. Although serious maternal complications occurred in this series, many are avoidable as we improve both our obstetric management and our anesthetic and surgical techniques. Prenatal intervention carries considerable maternal risk and should not be attempted clinically under any but the most rigorous conditions.