Table 2.

Summary effects of time specific exposure to prenatal smoking on neonatal body mass and composition

Models and Outcomes	Effect Size [β] (95% CI)†	p-value
Model 1: Smoked throughout pregnancy vs. non-smokers
Body mass (g)	−296 (−411, −180)	<0.001
Fat mass (g)	−81.2 (−127, −35.3)	<0.001
Fat-free mass (g)	−215 (−303, −126)	<0.001
F:FFM (g)	−0.02 (−0.04, −0.005)	0.008
Model 2: Smoked before late-pregnancy vs. non-smokers
Body mass (g)	59.9 (−102, 222)	0.47
Fat mass (g)	25.9 (−38.8, 90.6)	0.43
Fat-free mass (g)	34.0 (−89.6, 158)	0.59
F:FFM (g)	0.008 (−0.01, 0.03)	0.43
Model 3: Smoked throughout vs. before late-pregnancy
Body mass (g)	−371 (−559, −183)	<0.001
Fat mass (g)	−103 (−170, −36.1)	0.003
Fat-free mass (g)	−268 (−423, −113)	0.001
F:FFM (g)	−0.03 (−0.05, −0.002)	0.03

^†Adjusted by gestational and chronological age, offspring sex, gravidity, maternal age, race/ethnicity, educational status, household income, gestational weight gain, pre-pregnancy BMI and physical activity.