The first rule of management is that what is best for the mother's condition is usually best for the fetus. Controlled hypotension is however extremely hazardous for the fetus, and will likely produce demise. Fortunately, there are usually alternatives to hypotension, and neurosurgeon now routinely preclamp vessels feeding aneurysms and AV malformations. As a result, requests for controlled hypotension are less frequent and can usually be avoided during pregnancy. Systemic cooling to temperatures below 28 C carries a high risk of fetal cardiac arrest and demise.
Experience is reported of good fetal outcome following normothermic cardiopulmonary bypass.
In-Utero Fetal Surgery Advances in prenatal diagnosis and the development of percutaneous and open fetal surgical procedures now enables treatment of fetal abnormalities that would otherwise produce progressive organ damage and neonatal demise if untreated prior to delivery. Congenital bilateral hydronephrosis can be prevented by the percutaneous placement of vesicoamniotic shunts or bladder marsupialization. We have successfully carried out fetoscopic umbilical cord ligation at 24 weeks' gestation, and others have developed techniques for laser separation of the placental beds. The high risk of premature labor associated with these procedures has led to the development of aggressive prophylactic protocols. Many medical and ethical questions are raised by fetal surgery.