Measurement of serum concentrations of inhibin‐A (α‐β_A dimer) during human pregnancy

Abstract

Inhibin-A, principally the 31-kDa form, is present in peripheral blood throughout human gestation at concentrations up to 50 times greater than maximum values found during the spontaneous menstrual cycle (approximately 100 ng/l). The finding of highest serum values during the third trimester and of significant concentrations in term placenta firmly support a placental rather than luteal origin for this material.