Bivariate exposure–response functions for primary analysis (). Associations between each element (columns) and BW for GA z-score, setting a second element (rows) to its 25th, 50th, and 75th percentile and all other elements to their median, adjusting for maternal age, prepregnancy BMI, recruitment site, race by ethnicity and birth place, any maternal anemia in pregnancy, tobacco smoke exposure in pregnancy, and urinary arsenobetaine (AsB). Metals and urinary AsB were . Metals and all continuous covariates were also centered and scaled. Note: As, arsenic; BMI, body mass index; BW, birth weight; Cd, cadmium; Co, cobalt; GA, gestational age; Hg, mercury; Ni, nickel; Pb, lead; Tl, thallium.