Radiotelemetric fetal monitoring during and after open fetal operation

Diagnosis and treatment of fetal disease processes has advanced dramatically, but the ability to monitor the fetus in utero remains rudimentary. Open fetal operation provides a unique opportunity to correct life-threatening fetal abnormalities, but it also places the fetus at risk. Continuous intraoperative and post-operative fetal electrocardiographic monitoring may decrease the risk by optimizing fetal and maternal perioperative management. We tested an implantable radiotelemetry device that allowed continuous intraoperative and postoperative fetal electrocardiographic and temperature monitoring. The radiotelemetry device was placed subcutaneously in four fetal sheep at 100 to 112 days' gestation (term equals 145 days). During and after the fetal operation, the monitor reliably and continuously transmitted the analog fetal electrocardiogram and temperature. We then tested a similar device during human fetal operations on both an acute and a chronic basis. The radiotelemetry device permits continuous and reliable fetal monitoring during and after fetal operation and we now consider it essential to the operation. Its use should facilitate optimal fetal and maternal management and improve survival of the fetus.