Chronic Idiopathic Polyhydramnios: Evidence for a Defect in the Chorion Laeve Receptor for Lactogenic Hormones*

Abstract

Binding of human GH (hGH) to the lactogenicreceptor of human chorion laeve has been compared in membranepreparations from normal pregnancies and those complicatedby chronic idiopathic polyhydramnios. Specific binding of[¹²⁵I]hGH was significantly lower (mean ± SE, 1.64 ±0.28% n= 5) in chronic idiopathic polyhydramnios than in normal pregnancies(2.93g33.16±0.4% ; n = 16). Scatchard analysis data wereconsistent with a reduced lactogenic hormone receptorconcentrationbeing the explanation for this reduced hGH binding. Bycontrast, the specific binding of [¹²⁵I]insulin to its receptor wasunchanged when chorion laeve from hydramniotic pregnancies(7.29 ±1.98% ; n = 4) was compared with thatfrom normalpregnancies (8.63± 1.35% ; n = 7). We conclude that a lactogenichormone receptor defect exists in the chorion laeve of pregnanciescomplicated by chronic idiopathic polyhydramnios. Suchimpaired binding for PRL may explain the development ofexcessive amniotic fluid volumes, which is characteristic of thiscomplication ofpregnancy.(J Clin Endocrinol Metab56: 520,1983)