Table 4.

Association between maternal PbB level and preterm birth, and small for gestational age, upstate New York, 2003–2005.

	Preterm birth			Small for gestational age
Maternal PbB level	Cases (n)	aORa	95% CI	Cases (n)	aORb	95% CI
≤ 1.0	1,069	1.00	Reference	1,168	1.00	Reference
1.1–2.0	1,036	1.03	0.93–1.13	1,268	1.07	0.98–1.17
2.1–3.0	1,171	1.01	0.92–1.10	1,353	1.06	0.98–1.16
3.1–9.9	243	1.04	0.89–1.22	303	1.07	0.93–1.23

^aaORs are estimated from logistic regression with fractional polynomials after adjustment for timing of lead test, maternal age at delivery, race, Hispanic ethnicity, smoking, drug abuse, in wedlock, participation in special financial assistance program, parity, and infant sex. The quartiles of PbB concentration were untransformed, and fractional polynomials were used for maternal age.

^baORs are estimated from logistic regression with fractional polynomials after adjustment for timing of lead test, maternal age at delivery, race, education, smoking, drug abuse, in wedlock, participation in special financial assistance program, parity, and infant sex. The quartiles of PbB concentration were untransformed and fractional polynomials were assessed for maternal age.