Table 3.

Comparison of secondary outcome: proportion within or below BMI-related IOM guideline for weight gain during pregnancy

	Intervention	Usual care	Intervention–usual care
	n/N (%)	n/N (%)	Adjusted % difference (95% CI)	Adjusted OR (95% CI)	P value
Within IOM guideline*	96/305 (31.5)	108/311 (34.6)	−2.0 (−14.6 to 10.6)	0.92 (0.63 to 1.32)	0.63
Below IOM guideline*	125/305 (40.9)	114/311 (36.5)	4.9 (−7.4 to 17.2)	1.26 (0.86 to 1.82)	0.24

Analysis adjusted by Site, BMI category and midwife (random effect).

*Includes objective and self-reported weights; missing weights imputed using multiple imputation; pooled estimates.

BMI, body mass index; IOM, Institute of Medicine.