Maternal Recreational Exercise during Pregnancy in relation to Children’s BMI at 7 Years of Age

Table 2

Associations between maternal recreational exercise during pregnancy and the children's, body mass index at 7 years of age (z-scores of log-body mass index and differences in body mass index units), Danish National Birth Cohort, 1996–2002.

	Log-body mass index z-scores					Differences in body mass index units^c
Exercise
(hours/week)					𝑃-value
Early pregnancy	No.	Crude^a	Adjusted^b	95% CI	for trend
0	24,492	0	0	0		0	0
>0 to ≤1	5,707	−0.038*	−0.004	−0.032, 0.024		−0.02	−0.06, 0.05
>1 to ≤2	4,432	−0.065**	−0.021	−0.052, 0.010		−0.03	−0.09, 0.02
>2 to ≤3	2,377	−0.034	0.012	−0.029, 0.053		0.02	−0.05, 0.09
>3 to ≤5	2,152	−0.081**	−0.009	−0.051, 0.034		−0.02	−0.08, 0.06
>5	1,120	0.030	0.036	−0.022, 0.094	0.54	0.06	−0.03, 0.16
Exercise
(hours/week)
Late pregnancy
0	26,149	0	0	0		0	0
>0 to ≤1	5,942	−0.059**	−0.013	−0.040, 0.0l5		−0.02	−0.06, 0.03
>1 to ≤2	3,288	−0.038*	0.020	−0.015, 0.056		0.03	−0.03, 0.09
>2 to ≤3	1,386	−0.101**	−0.030	−0.082, 0.023		−0.05	−0.14, 0.03
>3 to ≤5	1,128	−0.056	0.018	−0.041,0.076		0.03	−0.06, 0.13
>5	598	−0.114**	−0.047	−0.126, 0.032	0.36	−0.08	−0.22, 0.06

CI: confidence interval.
* 𝑃<0.05, **𝑃<0.01 (𝑃 values are 2-sided).
^aCrude models adjusted for children’s age at follow-up.
^bAdditionally adjusted for maternal age, parity, pre-pregnancy body mass index, smoking and socio-economic status.
^cA djusted changes in body mass index units in a 7-year old girl with mean body mass index of 15.67 if the mother changes exercise habits from inactive to one of the repective active groups.