Placental IGF-I, estrogen receptor, and progesterone receptor expression, and maternal anthropometry in growth-restricted pregnancies in the Swedish population

Abstract

Background/aims: Fetal growth restriction is a complex problem of pregnancy arising from multiple etiologies. Key regulatory elements of growth are the insulin-like growth factor (IGF) axis, and estrogen and progesterone receptors. The aims were to determine the relations of expression of IGF-I, estrogen receptors α and β (ERα and ERβ, respectively), and progesterone receptor (PR), with maternal anthropometry, focusing on birth weight outcomes.

Methods: Placental samples were obtained from 33 patients following delivery. mRNA expression was determined by a solution hybridization technique. Samples were divided into normal control (NC) and growth-restricted (GR) groups.

Results: IGF-I expression was lower in the GR as compared to the NC group. PR levels correlated positively with IGF-I expression, infant anthropometry, and gestational age (GR). ERα correlated positively with PR expression (NC), and maternal BMI at delivery (GR). ERβ correlated positively with maternal delivery weight and gestational age (NC).

Conclusion: The differences in placental expression of IGF-I emphasize its key role in birth weight outcomes. We further suggest the importance of PR expression in the pathogenesis of intrauterine growth restriction, as there were direct correlations of PR expression with both IGF-I expression and infant anthropometric parameters, as well as gestational age.