Associations of maternal soy product consumption and urinary isoflavone concentrations with neonatal anthropometry: A prospective cohort study

Isoflavones (ISOs) are naturally occurring endocrine-disrupting compounds. Few human studies have evaluated the effects of ISO exposure on neonatal anthropometry. This study aimed to examine the associations of maternal soy product consumption and urinary ISO concentrations, including genistein, daidzein, glycitein, and equol, with neonatal anthropometry, based on a Chinese cohort study. In Shanghai-Minhang Birth Cohort Study, pregnant women at 12–16 weeks of gestation were recruited, and they completed a structured questionnaire to assess soy product consumption during pregnancy. They also provided a single spot urine sample for the ISO assay. Neonatal anthropometric indices (birth weight; arm, waist, and head circumference; and triceps, back, and abdominal skinfold thickness) were measured at birth. Multivariable linear regression analysis was performed among the 1188 mother-infant pairs to examine the associations between maternal soy product consumption and neonatal anthropometry. The same statistical model was applied to examine the associations between maternal ISO exposure and neonatal anthropometry among 480 mother-infant pairs. Neonate girls born to mothers who “sometimes” and “frequent” consumed soy products had 169.1 g (95% confidence interval [CI], −68.9–407.1) and 256.5 g (95% CI, 17.1–495.8) higher birth weight, respectively, than those born to mothers who “never” consumed soy products during pregnancy. We observed consistent associations between higher maternal urine ISO concentrations and increased anthropometric indices (birth weight, arm and waist circumference, and triceps and abdominal skinfold thickness) in neonate girls, while no association was observed among boys. The findings suggested that maternal dietary ISO intake during pregnancy is associated with fetal development in a sex-specific pattern. In addition, follow-up studies are required to evaluate whether the observed changes in anthropometric indices at birth are associated with health conditions later in life.