Placental 11B-Hydroxysteroid Dehydrogenase Type 2 mRNA Levels in Intrauterine Growth Restriction versus Small-for-Gestational-Age Fetuses

Introduction: The objective of this study was to evaluate placental 11B-hydroxysteroid dehydrogenase type 2 (11B-HSD- 2) mRNA levels in intrauterine growth-restricted fetuses (IUGR) as compared with small-for-gestational-age (SGA) fetuses according to clinical criteria. Material and Methods: Placental levels of 11B-HSD-2 mRNA levels were measured in SGA (birth weight <10th centile) and gestational-age-matched, appropriate-for-gestational-age (AGA) births. SGA was classified as IUGR (birth weight <3rd centile or <10th percentile with abnormal uterine artery Doppler or cerebroplacental ratio) or non-IUGR SGA. After RNA extraction, mRNA levels were determined by reverse transcription and quantitative PCR. Results: A total of 38 placentas were analyzed (20 AGA and 18 SGA). Among the SGA pregnancies, 13 qualified as IUGR. The activity of 11B-HSD-2 in IUGR pregnancies [0.105 (SD 0.328)] was significantly reduced compared to non-IUGR SGA [0.304 (SD 0.261); p = 0.018] and AGA [0.294 (SD 0.328); p = 0.001]. These differences remained significant after adjusting for potential confounders (such as smoking or maternal cortisol levels). Activity levels did not significantly differ between non-IUGR SGA and AGA. Discussion: IUGR fetuses had reduced 11B-HSD-2 activity in comparison with SGA and normally grown fetuses. This finding provides opportunities to develop new placental biomarkers for the phenotypic characterization of fetal smallness. (C) 2015 S. Karger AG, Basel