SERUM IMMUNOACTIVE INHIBIN LEVELS IN EARLY-PREGNANCY AFTER INVITRO FERTILIZATION AND EMBRYO TRANSFER

Objective: To determine the maternal serum concentrations of inhibin, E2, P, and hCG in early pregnancies arising from IVF and ET or GIFT an d to assess the value of these hormone measurements in determining out come of pregnancy. Design: Serum immunoactive inhibin, E2, P, and hCG levels were measured in the first trimester of pregnancies after IVF-E T and GIFT procedures. Setting: In vitro fertilization and ET or GIFT was undertaken at Monash IVF, Melbourne, Victoria, Australia. Patients : At least two blood samples were collected from 117 women between 4 a nd 11 weeks of gestation. Main Outcome Measures: The hormone concentra tions in the IVF-ET and GIFT pregnancies were compared with those in p regnancies and related to outcome of pregnancy. Results: Serum inhibin levels in singleton pregnancies were significantly higher than in com parable normal pregnancies. In contrast to normal conceptions in which inhibin concentrations rose to peak at 11 weeks, the levels found in IVF-ET and GIFT singleton pregnancies were high at 5 weeks' gestation and declined subsequently. In twin pregnancies, the inhibin levels wer e significantly greater than those in singleton pregnancies. In bioche mical pregnancies diagnosed by increasing hCG concentrations in the ab sence of an embryonic sac, inhibin levels were significantly lower tha n those found in singleton pregnancy, as were E2, P, and hCG levels. I n anembryonic pregnancies, diagnosed by the confirmation of an intraut erine gestation sac with no evidence of a fetal complex, inhibin conce ntrations were highest at week 4 and declined, being significantly low er at all stages of gestation. In ectopic pregnancy, serum inhibin lev els were lower at all stages of gestation, whereas E2 concentrations w ere not lower until 6 weeks and P levels until week 5. Serum hCG level s were significantly lower at all stages of gestation. In women with s pontaneous abortions, inhibin levels were lower than singleton pregnan cies at 7 weeks. Conclusions: Serum inhibin concentrations are elevate d in pregnancies arising from ovarian hyperstimulation in the first tr imester when compared with those in normal pregnancy, probably as a re sult of the presence of multiple corpora lutea resulting from ovarian hyperstimulation. Serum inhibin, E2, P, and hCG are useful markers of abnormal pregnancy outcome.