Early elevated alkaline phosphatase increases the risk of large-for-gestational-age birth weight in pregnant women with normal glucose tolerance

Abstract Aims The aim of this study was to assess the association between levels of alkaline phosphatase (ALP) in early pregnancy and the incidence of large-for-gestational-age (LGA) neonates in pregnant women without gestational diabetes mellitus. Methods A prospective cohort was carried out in 544 women and their biochemical parameters including serum ALP and demographic characteristics were collected in 13–16th gestational week. At 24–28th weeks of gestation, 50 g oral glucose challenge test and oral 75 g glucose tolerance test was performed. LGA was defined as birth weight ≥ 90th percentile for completed week of gestational age based on the sex-specific growth curves. Logistic regression and receiver operating characteristic analysis were utilized to identify independent risk factors and odds ratio among ALP quartiles for incidence of LGA. Results Women diagnosed as LGA held higher level of ALP than women in non-LGA group ( P  = 0.008). Moreover, ALP (odds ratio (OR) 1.05 [95% confidence interval (CI): 1.00, 1.10]) was the independent risk factors associated with LGA. Compared with ALP quartile 1, women in quartile 4 had more than 2.5-fold increased odds of LGA (OR 3.78, 95% CI: 1.10, 13.02), and the risk reached 4 times after adjusting several covariates (OR 4.15, 95% CI: 1.14,15.13). Conclusions A significantly increased risk of LGA was associated with higher serum concentrations of ALP in pregnant women with NGT, even it is in normal reference range.