Intrauterine, Infant, and Childhood Factors and Ovarian Reserve in Young African American Women

Early Life Anti-Müllerian Hormone Trajectories in Infant Girls

BACKGROUND

Minipuberty is a period of increased reproductive axis activity in infancy, but the importance of this period is not well understood, especially in girls. Previous studies reported a peak in hormone concentrations at 3 to 4 months old. Our objective is to describe anti-Müllerian hormone (AMH) trajectories in the context of other minipuberty factors among healthy infant girls using longitudinal measures of AMH.

METHODS

The Infant Feeding and Early Development study is a longitudinal cohort study of healthy infants, recruited from hospitals in the Philadelphia area during 2010 to 2013. We measured AMH in 153 girls who contributed 1366 serum samples across 11 study visits over 36 weeks. We also measured follicle stimulating hormone (FSH), estradiol, and ovarian characteristics. We used latent class mixed effects models to cluster trajectories of AMH concentration with age. Using linear mixed models, we estimated FSH and ovarian characteristic trajectories separately by AMH cluster.

RESULTS

We classified infants into four clusters that represent patterns of AMH that were high and decreasing (decreasing), had a peak around 12 weeks or 20 weeks (early peak and middle peak), or were consistently low (low). Infants in these clusters differed in their FSH trajectories, timing of estradiol production, and ovarian characteristics.

CONCLUSIONS

The AMH clusters identified suggest variation in the timing and the magnitude of the minipuberty response in infant girls. The decreasing and low clusters have not been described previously and should be further evaluated to determine whether they represent an opportunity for the early identification of later reproductive conditions.

Early-life Farm Exposure and Ovarian Reserve in a US Cohort of Women

BACKGROUND

In a previous exploratory study, we reported lower concentrations of the ovarian reserve biomarker anti-Müllerian hormone (AMH) in adulthood with prenatal farm exposure. We now examine this association as well as childhood farm exposure using enrollment data from the Sister Study, a large US cohort of women.

METHODS

We collected prenatal and childhood farm exposure data by questionnaire and telephone interview. However, serum AMH data were available only for a nested subset: premenopausal women ages 35-54 subsequently diagnosed with breast cancer (n = 418 cases) and their matched controls (n = 866). To avoid potential bias from restricting analyses to only premenopausal controls, we leveraged the available cohort data. We used data from both premenopausal cases and controls as well as postmenopausal women ages 35-54 (n = 3,526) (all presumed to have undetectable AMH concentrations) and applied weights to produce a sample representative of the cohort ages 35-54 (n = 17,799). The high proportion of undetectable AMH concentrations (41%) was addressed using reverse-scale Cox regression. An adjusted hazard ratio (HR) <1.0 indicates that exposed individuals had lower AMH concentrations than unexposed individuals.

RESULTS

Prenatal exposure to maternal residence or work on a farm was associated with lower AMH concentrations (HR 0.66; 95% confidence intervals [CI] = 0.48 to 0.90). Associations between childhood farm residence exposures and AMH were null or weak, except childhood contact with pesticide-treated livestock or buildings (HR 0.69; 95% CI = 0.40 to 1.2).

CONCLUSIONS

Replication of the prenatal farm exposure and lower adult AMH association raises concern that aspects of prenatal farm exposure may result in reduced adult ovarian reserve.