Development of reproductive system components involved in the pathophysiology of menstrual pain begins in utero and continues during infancy. Exogenous oestrogenic exposure in infancy (such as to soy-based formula) could plausibly result in persistent changes, leading to menstrual pain in adulthood.

Upson et al. gathered data from 1696 African–American women aged 23–35 years. Whether they were fed soy formula as babies, how long for and whether this started within 2 months of birth was noted by self-administered questionnaire for 1553 participants, 89% of whom were assisted by their mothers. Information on menstrual pain indicators was collected by web and telephone interview. Women ever fed soy formula as infants were more likely than unexposed women to report use of hormonal contraception for menstrual pain (RR 1.4, CI: 1.1–1.9) and moderate/severe menstrual discomfort/pain with ‘most periods’, but not ‘every period’, in early adulthood (ages 18–22 when not using hormonal contraception) (RR 1.5, CI: 1.1–2.0).

This adds to the growing literature on the reproductive health consequences of early life exposure to soy formula.

Read the full article in Human Reproduction doi:10.1093/humrep/dey303