Table 2.

Predictors of Small for Gestational Age Birth in Bivariate and Multivariate Models

	Not SGA	SGAa	OR (95% CI)	Full population; model 1	Full population; model 2	Prepregnancy smokers only; model 1	Prepregnancy smokers only; model 2
Row percent (95% CI)b
Perinatal IPV
No	90.9 (90.7, 91.0)	9.1 (9.0, 9.3)	REF	REF	REF	REF	REF
Yes	87.7 (86.9, 88.6)	12.3 (11.4, 13.1)	1.39 (1.28, 1.51)	1.18 (1.08, 1.28)	1.05 (0.97, 1.15)	1.15 (1.03, 1.29)	1.10 (0.98, 1.23)
Age
<20	87.0 (86.3, 87.8)	13.0 (12.2, 13.7)	1.70 (1.58, 1.83)	1.40 (1.28, 1.52)	1.40 (1.29, 1.53)	1.01 (0.88, 1.16)	1.11 (0.97, 1.28)
20–24	88.9 (88.4, 89.3)	11.1 (10.7, 11.6)	1.43 (1.36, 1.51)	1.27 (1.19, 1.35)	1.21 (1.14, 1.29)	1.02 (0.91, 1.13)	1.05 (0.95, 1.17)
25–29	91.3 (91.0, 91.6)	8.7 (8.4, 9.0)	1.09 (1.03, 1.15)	1.06 (1.01, 1.12)	1.03 (0.98, 1.09)	0.92 (0.83, 1.02)	0.94 (0.85, 1.04)
≥30	92.0 (91.7, 92.2)	8.0 (7.8, 8.3)	REF	REF	REF	REF	REF
Education
<12 years	88.1 (87.6, 88.7)	11.9 (11.3, 12.4)	1.37 (1.29, 1.46)	1.05 (0.98, 1.12)	0.99 (0.93, 1.06)	1.15 (1.04, 1.27)	1.05 (0.95, 1.16)
≥12 years	91.1 (90.9, 91.3)	8.9 (8.7, 9.1)	REF	REF	REF	REF	REF
Income—% federal poverty guidelines
<100	88.2 (87.9, 88.6)	11.8 (11.4, 12.1)	1.59 (1.52, 1.67)	1.33 (1.25, 1.41)	1.19 (1.12, 1.26)	1.40 (1.26, 1.55)	1.18 (1.06, 1.31)
101–200	91.0 (90.6, 91.4)	9.0 (8.6, 9.4)	1.18 (1.12, 1.25)	1.07 (1.01, 1.14)	1.01 (0.95, 1.07)	1.13 (1.01, 1.26)	1.01 (0.90, 1.13)
≥200	92.3 (92.0, 92.5)	7.7 (7.5, 8.0)	REF	REF	REF	REF	REF
Perinatal smoking pattern
Nonsmoker	91.8 (91.6, 92.0)	8.2 (8.0, 8.4)	REF	—	REF	—	—
Quit during pregnancy	91.3 (90.7, 91.8)	8.7 (8.2, 9.3)	1.07 (1.00, 1.15)	—	1.09 (1.02, 1.18)	—	REF
Sustained smoking	83.1 (82.5, 83.8)	16.9 (16.2, 17.5)	2.28 (2.16, 2.40)	—	2.06 (1.95, 2.18)	—	1.87 (1.73, 2.03)
Adequacy of prenatal care
Inadequate	89.4 (88.8, 90.0)	10.6 (10.0, 11.2)	1.24 (1.15, 1.33)	0.99 (0.92, 1.06)	0.98 (0.91, 1.05)	1.00 (0.89, 1.12)	0.98 (0.87, 1.10)
Intermediate	90.0 (89.4, 90.5)	10.0 (9.5, 10.6)	1.16 (1.09, 1.24)	1.10 (1.03, 1.18)	1.10 (1.03, 1.18)	1.14 (1.01, 1.29)	1.14 (1.01, 1.29)
Adequate	91.3 (91.0, 91.5)	8.7 (8.5, 9.0)	REF	REF	REF	REF	REF
Adequate plus	90.6 (90.3, 90.9)	9.4 (9.1, 9.7)	1.09 (1.03, 1.14)	1.06 (1.01, 1.11)	1.04 (0.99, 1.09)	1.03 (0.94, 1.12)	1.01 (0.93, 1.10)
Gestational weight gain
Inadequate	85.8 (85.4, 86.3)	14.2 (13.7, 14.6)	1.49 (1.41, 1.57)	1.42 (1.35, 1.50)	1.41 (1.34, 1.49)	1.47 (1.34, 1.62)	1.43 (1.30, 1.57)
Normal	90.0 (89.7, 90.3)	10.0 (9.7, 10.3)	REF	REF	REF	REF	REF
Excessive	93.3 (93.1, 93.5)	6.7 (6.5, 6.9)	0.65 (0.61, 0.68)	0.63 (0.60, 0.66)	0.62 (0.59, 0.66)	0.58 (0.53, 0.64)	0.61 (0.56, 0.66)

^aSGA as operationalized in PRAMS is adjusted for maternal race/ethnicity.

^bAll percentages, odds ratios, and confidence intervals reported are from survey-weighted procedures.

PRAMS, Pregnancy Risk Assessment Monitoring System.