Acute feto-maternal transfusion--diagnostic considerations.

A sinusoidal fetal heart rate pattern followed by severe deceleration was encountered in a fetus at 39 weeks' gestation during antepartum fetal nonstress testing. The only indication for fetal monitoring was a maternal complaint of cessation of fetal movements. The abdominally-delivered newborn was found to be severely anaemic and the cord was tightly wrapped round its body. A pathophysiological mechanism for massive feto-maternal transfusion is suggested. Various laboratory tests were utilized to identify the condition, quantitate the amount of transfusion, and estimate the time of its occurrence. Globin synthesis studies in maternal blood indicated that a significant fetal blood loss had occurred within 24 hours of delivery. The significance of these findings as applied to the clinician is discussed.