Body surface area at birth and later risk for gestational diabetes mellitus among primiparous women

AIMS: To assess the relationship between body surface area (BSA) at birth and future risk for gestational diabetes mellitus (GDM). METHODS: This is an observational cohort study from Vantaa, Finland. The cohort included 1548 Finnish primiparous women, aged 15–28 years, without pre-existing diabetes, who gave birth 2009–2015. All women were born full-term and had complete information about their birth weight and length, from the Finnish Medical Birth Register. Additional data for the study were provided by individual patient health records and Statistics Finland. Study participants were divided into five levels (I–V) according to BSA at birth, based on normal distribution. RESULTS: There was an inverse association between BSA at birth and risk for GDM (p = 0.015 for linearity, after adjustments for age, educational attainment, pre-pregnancy BMI and smoking). The odds ratio (OR) for GDM in level V, with the largest BSA at birth, compared with level I, with the smallest BSA at birth, was 0.43 [95% confidence interval (CI) 0.22–0.83]; adjusted for age, educational attainment, pre-pregnancy body mass index and smoking. The OR for GDM was 0.8 (95% CI 0.68–0.95, p = 0.009) for each one standard deviation increase in BSA at birth, adjusted for the same confounders. BSA at birth correlated with adult anthropometry: correlation coefficients were r = 0.16 (95% CI 0.11–0.21) for weight, r = 0.31 (95% CI 0.26–0.35) for height, and r = 0.06 (95% CI 0.01–0.11) for BMI. CONCLUSIONS: Body surface area at birth is inversely associated with future risk for GDM in primiparous women.