Maternal plasma transforming growth factor-β1 (TGF-β1) and newborn size: the Araraquara Cohort Study.

Objective: To investigate associations of maternal and cord blood cytokine patterns with newborn size and body composition.

Methods: This cross-sectional study involved 70 pregnant women and their healthy newborns selected from the "Araraquara Cohort Study". Newborn anthropometric measurements were recorded at birth. Body composition was evaluated by air displacement plethysmography. Maternal blood samples were collected from pregnant women between 30 and 36 weeks of gestation, and umbilical cord blood samples were collected immediately after placenta discharge. The concentrations of the cytokines were determined in plasma by ELISA. Multiple linear regression models were used to assess associations between maternal and cord blood cytokine concentrations and newborn anthropometry and body composition measurements.

Results: Maternal plasma TGF-β1 concentration was inversely associated with newborn weight (β = -43.0; p = 0.012), length (β = -0.16, p = 0.028), head circumference (β = -0.13, p = 0.004), ponderal index (β = -0.32, p = 0.011) and fat-free mass (β = -0.05, p = 0.005). However, the association persisted just for head circumference (β = -0.26; p = 0.030) and ponderal index (β = - 0.28; p = 0.028), after adjusting for pre-gestational BMI, gestational weight gain, gestational age, hours after delivery, newborn sex, smoking and alcohol consumption.

Conclusions: Maternal plasma TGF-β1 concentration may be involved in the regulation of newborn size, mainly head circumference and ponderal index. Further cohort studies are necessary to investigate the role of TGF-β1 in different trimesters of pregnancy and its effect during the early stages of fetal development.