Timing of gestational diabetes diagnosis, gestational weight gains and offspring growth trajectory: a prospective birth cohort study.

BACKGROUND: The evidence on the associations of the timing of maternal gestational diabetes mellitus (GDM) with the comprehensive growth trajectory from perinatal to early childhood in offspring is limited. The potential mechanism remains elusive. Our aim is to estimate the associations of the timing of GDM diagnosis and gestational weight gains (GWG) with the growth trajectory of children from perinatal to early childhood. METHODS: A total of 7609 participants are included from the Maternal & Infants Health in Hefei cohort study. Primary predictors were the timing of maternal GDM diagnosis and GWG during pregnancy. The main outcomes included fetal ultrasonic measurements, birth size as well as BMI peak indicators during infancy within 48 months. RESULTS: GDM diagnosed before 26 weeks was associated with increased risks of overgrowth for fetal abdominal circumference (OR 1.19, 95% CI 1.04-1.36) and birth weight (OR 1.51, 95% CI 1.19-1.91) when compared with unexposed. GDM diagnosis < 26 weeks was related to the higher BMI peak (ß 0.16, 95%CI 0.03-0.28) within 48 months. The significantly additive impacts of maternal early GDM diagnosis and excessive gestational weight gains (EGWG) on offspring overgrowth were observed. Women in GDM < 26 weeks with early EGWG group had higher levels of hsCRP compared with GDM > 26 weeks (P < 0.001). CONCLUSIONS: Exposure to maternal GDM diagnosed before 26 weeks with early EGWG could lead to shifts and/or disruptions from the typical growth trajectory from perinatal to early childhood in offspring.

Maternal 25(OH)D attenuates the relationship between ambient air pollution during pregnancy and fetal hyperinsulinism.

Inflammatory responses have been demonstrated to link air pollution with insulin resistance and type 2 diabetes in adults. However, few studies have focused on the relationship between prenatal air pollution and fetal ß-cell function and the mediating effect of systematic inflammation remains elusive. Whether the anti-inflammatory effect of vitamin D could attenuate the ß-cell dysfunction in early life warrants further investigations. We aimed to determine whether maternal blood 25(OH)D attenuates the associations of ambient air pollution during pregnancy with fetal hyperinsulinism mediated by maternal inflammatory response. A total of 8250 mother-newborn pairs were included between 2015 and 2021 in the Maternal & Infants Health in Hefei study. Weekly mean air pollution exposure to fine particles (PM2.5 and PM10), SO2, and CO was estimated across pregnancy. Maternal serum samples in the third trimester were used to measure the high-sensitivity c-reactive protein (hs-CRP) and 25(OH)D. Cord blood samples at delivery were collected for the measurement of C-peptide. Fetal hyperinsulinism was based on cord C-peptide >90th centile. An increased fetal hyperinsulinism risk was associated with per 10 µg/m3 increase in PM2.5 [odds ratios (OR): 1.45 (95% confidence interval (CI):1.32, 1.59)], per 10 µg/m3 increase in PM10 [OR = 1.49 (95% CI:1.37, 1.63)], per 5 µg/m3 increase in SO2 [OR = 1.91 (95% CI: 1.70, 2.15)], and per 0.1 mg/m3 increase in CO [OR = 1.48 (95% CI:1.37, 1.61)] across pregnancy. Mediation analysis showed a 16.3% contribution of maternal hsCRP to the relationship between air pollution throughout pregnancy and fetal hyperinsulinism. Air pollution-associated higher levels of hsCRP and risk of fetal hyperinsulinism could be attenuated by higher maternal 25(OH)D levels. Prenatal ambient air pollution exposures were associated with an increased fetal hyperinsulinism risk mediated by maternal serum hsCRP. Higher antenatal 25(OH)D levels could attenuate air pollution-induced inflammatory responses and hyperinsulinism risk.