Table 3:

Neonatal Outcomes According to the Institute of Medicine Gestational Weight Gain Categories

Outcome	Gestational Weight Gain
	Below N=6,338			Within (referent) N=8,296	Above N=15,227
	N (%)	Unadjusted OR (95%CI) p-value	Adjusted OR (95%CI) p-value	N (%)	N (%)	Unadjusted OR (95%CI) p-value	Adjusted OR (95%CI) p-value
Preterm birth*	751 (11.9%)	1.59 (1.42–1.77) p<0.001	1.47 (1.31–1.64) p<0.001	648 (7.8%)	1324 (8.7%)	1.12 (1.02–1.24) p=0.02	1.05 (0.95–1.16) p=0.32
Spontaneous preterm birth*	471 (7.4%)	1.59 (1.39–1.82) p<0.001	1.50 (1.31–1.73) p<0.001	399 (4.8%)	712 (4.7%)	0.97 (0.86–1.10) p=0.64	0.93 (0.82–1.06) p=0.27
Indicated preterm birth*	280 (4.4%)	1.49 (1.26–1.78) p<0.001	1.34 (1.12–1.60) p=0.002	249 (3.0%)	612 (4.0%)	1.35 (1.17–1.57) p<0.001	1.24 (1.07–1.45) p=0.006
Shoulder dystocia in vaginal delivery only *†	85 (1.9%)	0.87 (0.66– 1.15) p=0.34	0.86 (0.65–1.13) p=0.28	126 (2.1%)	357 (3.6%)	1.71 (1.39–2.10) p<0.001	1.74 (1.41–2.14) p<0.001
Macrosomia * ‡‡	35 (0.55%)	0.68 (0.45–1.03) p=0.07	--	67 (0.81%)	317 (2.08%)	2.61 (2.00–3.40) p<0.001	2.66 (2.03–3.48) p<0.001
Treatment for neonatal hypoglycemia * ‡‡	45 (0.71%)	1.16 (0.77–1.73) p=0.48	--	51 (0.61%)	149 (0.98%)	1.60 (1.16–2.20) p=0.004	1.60 (1.16–2.22) p=0.005

^*The analysis was adjusted for maternal age, race-ethnicity, tobacco use, parity, insurance type, chronic hypertension, pre-gestational diabetes, and hospital type.

^†The denominator for the shoulder dystocia outcome varies from the total sample size because it was limited to women with vaginal deliveries (N=4,587 below; N=5,948 within; N=10,002 above).

^‡‡Due to the low frequency of macrosomia and neonatal hypoglycemia and gestational weight gain below the guidelines, the adjusted ORs were not reported.

The bolded values indicate statistical significance.

OR odds ratio

CI Confidence interval