TABLE 2.

Association of Maternal Prepregnant Body Mass Index With Selected Birth Defects

Body Mass Index; kg/m2	No. Controls	No. Cases	OR (95% CI)	Adjusted ORa (95% CI)
Anencephaly
≥30	81	27	1.6 (1.0–2.6)	1.4 (0.8–2.4)
25–29.9	131	25	0.9 (0.6–1.5)	0.9 (0.5–1.5)
18.5–24.9c	340	71	1.0	1.0
<18.5	30	2	0.3 (0.1–1.4)	0.3 (0.1–1.4)
Missing	41	14
Continuous measureb	582	125	1.04 (1.00–1.07)	1.03 (0.99–1.07)
Spina bifida
≥30	81	28	1.4 (0.8–2.2)	1.2 (0.7–2.0)
25–29.9	131	44	1.3 (0.9–2.0)	1.3 (0.8–2.0)
18.5–24.9c	340	87	1.0	1.0
<18.5	30	5	0.7 (0.2–1.7)	0.7 (0.2–1.8)
Missing	41	22
Continuous measureb	582	164	1.02 (0.99–1.05)	1.01 (0.98–1.05)
d-Transposition of great arteries
≥30	93	14	0.7 (0.4–1.4)	0.8 (0.4–1.6)
25–29.9	146	35	1.2 (0.8–1.8)	1.2 (0.8–2.0)
18.5–24.9c	375	76	1.0	1.0
<18.5	36	3	0.4 (0.1–1.4)	0.4 (0.1–1.5)
Missing	45	8
Continuous measureb	650	128	1.01 (0.97–1.04)	1.02 (0.98–1.06)
Tetralogy of fallot
≥30	93	16	0.8 (0.4–1.4)	0.7 (0.4–1.4)
25–29.9	146	39	1.2 (0.8–1.8)	1.3 (0.8–2.0)
18.5–24.9c	375	85	1.0	1.0
<18.5	36	10	1.2 (0.6–2.6)	1.3 (0.6–2.7)
Missing	45	15
Continuous measureb	650	150	0.97 (0.94–1.01)	0.97 (0.93–1.01)

^aOdds ratio adjusted for race/ethnicity, education, vitamin use, total energy intake, maternal height, and dietary folate intake.

^bOdds ratio expressed as change in risk per 1 unit change in body mass index.

^cReference category.