Increased maternal serum placental growth hormone variant in pregnancies complicated by otosclerosis

To investigate the potential role of maternal serum concentrations of placental growth hormone variant (GH-V), insulin-like growth factor (IGF) 1 and 2, and IGF-binding proteins (IGFBP) 1 and 3 in pregnancies complicated by otosclerosis.

Otosclerosis cases (n = 22) and age, ethnicity-matched controls (n = 22) were selected in a nested case-control study. Maternal serum hormone concentrations at 26 and 34 weeks of gestation were determined by enzyme-linked immunosorbent assay (ELISA).

Concentrations of all measured hormones except IGFBP-1 were increased as gestation progressed. Maternal serum GH-V concentrations at 26 and 34 weeks of gestation were significantly increased in the otosclerosis group, when compared to the control group (2.53 ± 0.17 ng/ml vs. 1.78 ± 0.19 ng/ml, P = 0.036; 4.34 ± 0.31 ng/ml vs. 3.12 ± 0.18 ng/ml, P < 0.001, respectively). Maternal serum IGF-1 concentrations at 34 weeks in otosclerotic patients were significantly higher than in the controls (589.1 ± 21.4 ng/ml vs. 499.7 ± 17.8 ng/ml, P < 0.001). The increase of IGF-1 was not observed at 26 weeks of gestation. Serum IGF-2, IGFBP-1 and IGFBP-3 at either 26 or 34 weeks were unaltered between the two groups.

Maternal serum concentrations of GH-V and IGF-1 were altered in pregnancy complicated by otosclerosis, suggesting that the GH-IGF axis may contribute to the development of this condition during pregnancy.