The Placenta Remains Functional Following Fetectomy in Baboons

The present study employed the dehydroepiandrosterone (DHA) loading test to determine if the placenta in baboons remains functional following fetectomy. A bolus iv injection of 100 mg DHA was given to 4 baboons prior to and at various intervals following fetectomy at midgestation. Blood samples were withdrawn over a 4-h period following DHA and assayed for estradiol (E2). Placentas were maintained in situ following removal of the fetus. Serum E2 reached peak concentrations 30-60 min after injection of DHA prior to and after fetectomy. Although initial serum E2 concentrations were very low after fetectomy, the mean +/- SE net increase (delta) in peak serum E2 concentrations following the DHA bolus were similar before (3.92 +/- 0.71 ng/ml) and after (3.72 +/- 0.64 ng/ml) fetectomy. Based on the capacity for aromatization, therefore, the placenta remains equally competent and functional in baboons despite chronic absence of the fetus.