Using a cohort of 110,447 singleton, term pregnancies, we aimed to validate the previously proposed customized standard of large-for-gestational-age (LGA) birthweight, derive an additional customized LGA model excluding maternal weight, and evaluate the association between differing definitions of customized LGA and perinatal morbidities.
In the final multiple model, excluding maternal age, the factor most strongly associated with LGA was BMI (p = 2.6 × 10−19), accounting for 4.3%% of the variance in the univariate setting (R = 0.043).
To compare the results for the full model with those for the less constrained models that exclude maternal height or birth length, we fitted reduced models to the combined Philippines and Guatemala samples by successively omitting terms for maternal height and birth length.
For the models that excluded maternal height, inclusion of the India cohort altered the estimates by only trivial amounts, and in models that included length at 12 mo and conditional heights at 24 mo and mid-childhood, addition of the Brazil and South Africa samples resulted in trivial changes to the estimates.
Six different animal models were fitted, differentiated by including or excluding maternal effects, with and without covariance between maternal and direct genetic effects.
Models with customised birth weight centile/SGA as outcomes were adjusted for the variables listed above excluding maternal ethnicity, parity and BMI which were taken into account in the centile calculation.
However, results were similar for maternal and perinatal morbidity after excluding maternal or perinatal death (data no shown).
WW (Weaning Weight): Adjusted to 205 days excluding maternal effects (evaluated as milk), in pounds (lbs).
YW (Yearling Weight): Adjusted to 365 days excluding maternal effects in pounds (lbs).
In models excluding the 71 sons who were born after the exposure period but before their mothers' PBB was measured (Table 4), males with PBB exposure > 5 ppb were three times as likely to report any GU condition compared with those with the lowest exposure (≤ 1 ppb; for maternal enrollment PBB ORR = 3.1; 95% CI, 1.0 9.1; for estimated maternal PBB at conception: OR = 2.68; 95% CI, 0.9 7.9).
