Table 2.

Associations between prenatal and postnatal average carbon monoxide (CO) and growth trajectories.

Trajectory measurementa	$N$	Bivariate model				$N$	Multivariable modelb
		Prenatal		Postnatal			Prenatal		Postnatal
		$\text{OR}$ (95% CI)	$p$-Value	$\text{OR}$ (95% CI)	$p$-Value		$\text{OR}$ (95% CI)	p	$\text{OR}$ (95% CI)	$p$-Value
Weight	1,144	1.03 (0.93, 1.12)	0.55	0.99 (0.93, 1.06)	0.77	1,142	1.03 (0.93, 1.14)	0.59	1.01 (0.94, 1.08)	0.84
Length	1,144	1.16 (1.01, 1.30)	0.046	1.01 (0.94, 1.08)	0.78	1,142	1.17 (1.01, 1.35)	0.04	1.03 (0.96, 1.10)	0.41
Head circumference	1,144	1.04 (0.96, 1.11)	0.33	1.07 (1.03, 1.11)	$<.001$	1,142	1.05 (0.98, 1.12)	0.19	1.09 (1.04, 1.13)	$<.001$
MUAC	1,144	1.05 (0.96, 1.14)	0.27	1.01 (0.94, 1.07)	0.84	1,142	1.07 (0.97, 1.19)	0.16	1.03 (0.97, 1.10)	0.35
Weight-for-length $z$-score	1,127	0.96 (0.86, 1.06)	0.40	0.97 (0.88, 1.05)	0.38	1,125	0.95 (0.85, 1.06)	0.38	0.97 (0.89, 1.06)	0.49
Length-for-age $z$-score	1,127	1.13 (0.98, 1.27)	0.10	0.97 (0.92, 1.01)	0.13	1,125	1.15 (1.01, 1.32)	0.03	0.98 (0.94, 1.02)	0.25
Weight-for-age $z$-score	1,130	0.99 (0.86, 1.13)	0.93	0.99 (0.91, 1.08)	0.86	1,128	1.00 (0.87, 1.14)	0.94	1.00 (0.93, 1.08)	0.93

Note: Per 1-ppm increase in average CO exposure, all effects determined with cluster-robust standard errors. Analyses are ordinal regression where the ORs may be interpreted as the odds of being in a lower/smaller trajectory per 1-ppm increase in average CO exposure. CI, confidence interval; OR, odds ratio; MUAC, mid-upper arm circumference.

^a All trajectories include four groups except length (3 groups) and head circumference (3 groups).

^b Multivariable models include both prenatal and postnatal average CO exposure and adjust for child sex, maternal age, ethnicity, and wealth index.