Maternal Pre-pregnancy BMI and Reproductive Health of Daughters in Young Adulthood

Objective To investigate the possible associations between maternal pre-pregnancy body mass index (BMI) and daughters’ age of menarche and subsequent markers of reproductive health. Methods Nine hundred eighty-five pregnant women (80 %) were enrolled at their routine 30th week examinations in 1988–1989. In 2008, a follow-up questionnaire was completed for 365 daughters (83 %), while 267 daughters (61 %) participated in a subsequent clinical examination. Main outcome measures were age of menarche, reproductive hormone profile, and ovarian follicle count in daughters. Results Daughters of mothers in the highest pre-pregnancy BMI tertile (BMI ≥ 22.0 kg/m2) had an adjusted 4.1 (0.3; 8.0) months earlier menarche compared with the middle tertile group (BMI 20.0–21.9 kg/m2). Among non-users of hormonal contraceptives, daughters of mothers in the highest pre-pregnancy BMI tertile had non-significantly lower dehydroepiandrosterone-sulphate (DHEAS), estradiol, and free estrogen index (FEI), compared to the middle BMI tertile. This was supported by a sub-analysis using the WHO classification (underweight, BMI < 18.50; normal range, BMI 18.50–24.99; overweight/obese, BMI ≥ 25.00 kg/m2) as exposure groups, in which daughters of overweight mothers had lower levels of DHEAS and estradiol, and lower FEI compared to daughters of normal weight mothers. No associations were found for ovarian follicle count in any of the groups. Conclusions for Practice We found that higher maternal BMI is associated with earlier age of menarche in daughters. A possible impact of maternal pre-pregnancy BMI on DHEAS and estradiol serum levels, and FEI in non-users of hormonal contraceptives was indicated, but the results were not statistically significant.