Joint associations of maternal gestational weight gain, pregravid obesity and onset of breast development in daughters
Category: Lifestyles Behavior, Energy Balance & Chemoprevention, Electronic Health Records (EHRs)
Conference Year: 2018
Purpose: To assess the joint associations between maternal gestational weight gain (GWG) and pregravid obesity on the timing of the onset of breast development (thelarche) in girls. Early puberty is a known risk factor for reproductive cancers, and the age of pubertal onset has decreased significantly over the past few decades. Investigation of modifiable, early life risk factors may help in the design of upstream cancer prevention strategies. Methods: Retrospective cohort study of 2,206 mother-daughter pairs where daughters were born in 2006-7 at Kaiser Permanente Northern California (KPNC). We used pediatrician-assessed pubertal maturation (Tanner) staging, documented in KPNC’s electronic health record to determine thelarche (transition from Tanner stage 1 to 2+.) Maternal pregravid height and weights measured during pregnancy were used to calculate GWG, which was categorized according to the 2009 Institute of Medicine recommendations. We created six composite exposure variables: GWG by pregravid body mass index (BMI, kg/m2: <25 vs. 25). Weibull regression accommodating interval censoring were used in all analyses. All models were adjusted for maternal age, gestational age at delivery and race/ethnicity. We also examined mediation by girl's pre-pubertal BMI. Results: The associations between GWG (exceeding or gaining below the recommendations) and risk of earlier thelarche were stronger and significant if mother had pregravid BMI>25. For instance, girls whose mother had BMI>25 and exceeded or gained below the GWG recommendations were at over 50% higher risk of experiencing earlier thelarche compared to girls whose mother met GWG recommendation and had BMI<25 [adjusted hazard ratio (HR)= 1.82; 95% confidence interval (CI) 1.47-2.26; HR=1.54; 95% 1.15-2.04, respectively]. When girl's BMI was included in the model, these associations were slightly attenuated but the association for excess GWG + BMI>25 remained significant [HR=1.53; 95%CI 1.22-1.91]. Conclusions: Maternal obesity and GWG may independently influence the timing of puberty in daughters, thereby increasing the risk of future cancers. Early life interventions such as monitoring of maternal weight before and throughout pregnancy, may have implications for future cancer risks in the offspring.
Keywords: Puberty Lifecourse Gestational weight gain Developmental Origin of Health and Disease Obesity