Excessive gestational weight gain (GWG) during pregnancy is associated with adverse outcomes for mothers and offspring. Early, mid, and late pregnancy GWGs have different associations with fetal growth and later life adiposity, but associations with cord blood hormones, which might predict later health, are not well studied.
In 978 pregnant women from the pre-birth Project Viva cohort, we calculated trimester-specific GWG using clinically recorded prenatal weights. Outcomes were levels of umbilical cord blood hormones related to fetal and postnatal growth. We used linear regression models adjusted for maternal race/ethnicity, pre-pregnancy BMI, parity, education, pregnancy smoking status and child sex; 2nd and 3rd trimester models were additionally adjusted for GWG in prior trimesters.
Mean±SD pre-pregnancy BMI was 24.9±5.5kg/m(2), 30% were non-white, and 63% were college graduates. Mean±SD cord blood hormone levels were insulin-like growth factor [IGF]-1 (56.4±24.3ng/mL), IGF-2 (408.5±92.7ng/mL), IGFBP-3 (1084±318ng/mL), insulin (6.5±7.2 uU/mL), C-peptide (1.0±0.6ng/mL), leptin (9.0±6.6ng/mL) and adiponectin (28.7±6.8μg/mL). Mean±SD 1st, 2nd and 3rd trimester GWG rates were 0.22±0.22, 0.49±0.19 and 0.46±0.22kg/wk. Greater 1st trimester GWG (per 0.2kg/wk) was associated with higher insulin (0.5 uU/mL; 95% CI 0.1, 0.9) and C-peptide (0.06ng/mL; 95% CI 0.02, 0.09) and lower adiponectin (-0.4μg/mL; 95% CI -0.9, 0.0). Greater 2nd trimester GWG (per 0.2kg/wk) was associated with higher IGF-1 (2.3ng/mL; 95% CI 0.6, 4.0), IGF-2 (7.9ng/mL; 95% CI 1.2, 14.6), IGFBP-3 (41.6ng/mL; 95% CI 19.4, 63.7) and leptin (0.9ng/mL; 0.4, 1.4). 3rd trimester GWG was not associated with cord blood hormones.
1st trimester weight gain appears to matter more for cord blood hormones related to offspring glucose/insulin regulation, whereas 2nd trimester gain matters more for hormones related to growth and adiposity.