SERUM INHIBIN LEVELS ARE LOWER IN ECTOPIC THAN INTRAUTERINE SPONTANEOUSLY CONCEIVED PREGNANCIES

Objective: To determine if serum inhibin concentrations are lower in e ctopic (EP) versus intrauterine pregnancies (IUPs) that are conceived spontaneously. Design: Case-control study. Setting: Academic clinical practice. Patients: Serum samples were obtained from 19 women who had EP confirmed at surgery and by pathology. For comparison, serum sample s were collected from 24 women of similar chronological and gestationa l age with sonographic evidence of an IUP. Main Outcome Measure: Serum dimeric inhibin-A, total inhibin, P, and hCG. Results: Serum total an d dimeric inhibin concentrations in women with EP were <60% of the con centrations for women with single IUPs. Total inhibin, but not dimeric inhibin-A, was elevated in maternal serum before week 8 of gestation relative to normal menstrual cycle levels. Conclusions: Serum inhibin concentrations are lower in EP as compared with IUPs that are spontane ously conceived and the relative amounts of dimeric inhibin-A, B, and alpha inhibin subunit in maternal serum may change throughout gestatio n.