Prepregnancy Physical Activity in relation to Offspring Birth Weight: A Prospective Population-Based Study in Norway—The HUNT Study

Table 4

Maternal pre-pregnancy body mass index (BMI) and leisure time physical exercise related to mean offspring birth weight from linear regression and odds ratio (OR) from logistic regression for a macrosomic infant (i.e., birth weight > 4000 g).

Combined categories of BMI and exercise^a	No. of; persons	Crude mean; difference	Adjusted^b mean; difference (95% CI)	No. of cases; (BW > 4000 g)	Crude OR	Adjusted^b OR; (95% CI)
<25 kg/m^2 and medium/high level	1,046	0.0	0.0 (reference)	206	1.0	1.0 (reference)
<25 kg/m^2 and no/low level	676	−8.6	−8.4 (−55.6 to 38.8)	131	1.0	1.0 (0.8–1.2)
≥25 kg/m^2 and medium/high level	186	29.8	33.1 (−42.5 to 108.7)	42	1.2	1.2 (0.8–1.8)
≥25 kg/m^2 and no/low level	118	129.7	134.1 (41.0 to 227.3)	37	1.9	1.9 (1.2–2.9)

CI: confidence interval; BW: birth weight.
^aBased on a summary score of frequency, duration, and intensity of exercise.
^bAdjusted for maternal age (20–24, 25–29, 30–34, and 35–39 years), smoking (never, former, current, and unknown), and parity (primiparous, 1-2 children, and 3–6 children).