Elevated maternal osteocalcin during early pregnancy ups risk of low birthweight
Elevated levels of maternal osteocalcin during the first and second trimesters of pregnancy may increase the risk of having low birthweight (LBW) infants, a recent study has found.
Researchers performed a nested case-control study of 230 mothers (mean age 28.0±5.0 years) with LBW babies and 382 control pregnant mothers (mean age 28.1±4.7 years). Participants were matched for infant gender, maternal age and gestational age at blood sampling. Binary logistic regression models were used to estimate the relationship between maternal serum osteocalcin and 25-hydroxyvitamin D (25(OH)D) and LBW.
Relative to women with first trimester maternal osteocalcin ≤11.32 ng/mL, those with elevated levels were significantly more likely to give birth to LBW babies (20 vs 40; adjusted odds ratio [OR], 2.29; 95 percent CI, 1.11–4.72; p=0.025).
No such effect was documented for maternal 25(OH)D. There were 25 LBW infants in those with serum concentrations ≤64.82 nmol/L, which was not significantly different than in those with high measured levels (n=35; adjusted OR, 1.39; 0.72–2.67; p=0.325).
During the second trimester, the effect of osteocalcin remained significant (adjusted OR, 1.59; 1.03–2.45; p=0.036) while serum 25(OH)D continued to be unrelated to LBW risk (adjusted OR, 1.06; 0.69–1.62; p=0.790).
By the third trimester, the relationship between LBW risk and osteocalcin was attenuated (adjusted OR, 1.05; 0.40–2.80; p=0.919).
That osteocalcin acts as a hormone that improves glucose uptake by the foetus may explain the present findings, though further studies are required to conclusively identify the underlying mechanisms, said researchers.