Small for gestational age and age at menarche in a contemporary population-based U.S. sample

Children born small for gestational age (SGA) may be at risk for earlier puberty and adverse long-term health sequelae. This study investigates associations between SGA and age at menarche using secondary data on 1,027 female children in a population-based U.S. birth cohort that over-sampled non-marital births, which in the U.S. is a policy-relevant population. SGA was defined as <10^th percentile of weight for gestational age compared to the national U.S. distribution. We estimated unadjusted and adjusted Ordinary Least Squares (OLS) models of associations between SGA and age at menarche in years, as well as unadjusted and adjusted logistic regression models of associations between SGA and early menarche (before age 11). SGA was not significantly associated with earlier age at menarche, even when adjusting for maternal sociodemographic characteristics, prenatal smoking, and maternal pre-pregnancy overweight and obesity. Similarly, SGA was not significantly associated with the odds of menarche occurring before age 11. However, maternal non-Hispanic Black race-ethnicity, Hispanic ethnicity, and pre-pregnancy obesity all had independent associations with average earlier age at menarche and menarche before age 11. Thus, maternal risk factors appear to play more influential roles in determining pubertal development.