Table 3.

Maternal Caffeine Consumption and Risk of Selected Birth Defects, Overall and Cross-Classified by Potential Effect Modifiers, National Birth Defects Prevention Study, 1997 to 2005

	Controls	Anotia/microtia		Small intestinal atresia		Craniosynostosis		Omphalocele		Gastroschisis
Caffeine intake category	N*	N	aOR† (CI)	N	aOR†,‡ (CI)	N	aOR†,§ (CI)	N	aOR† (CI)	N	aOR†,|| (CI)
Nonsmokers
<10 mg/day	1079	60	1.0	31	1.0	122	1.0	33	1.0	86	1.0
10–<100 mg/day	2079	122	1.00 (0.72–1.39)	84	1.46 (0.96–2.24)	243	1.19 (0.94–1.51)	70	1.10 (0.71–1.68)	179	1.00 (0.75–1.33)
100–<200 mg/day	1226	83	1.12 (0.79–1.59)	42	1.26 (0.78–2.04)	163	1.28 (0.99–1.66)	43	1.15 (0.72–1.85)	107	1.30 (0.94–1.79)
200–<300 mg/day	600	42	1.27 (0.83–1.94)	31	2.01 (1.19–3.39)	58	0.85 (0.61–1.20)	31	1.56 (0.93–2.62)	37	1.04 (0.68–1.59)
300+ mg/day	376	27	1.38 (0.85–2.25)	15	1.64 (0.86–3.12)	66	1.57 (1.12–2.18)	18	1.39 (0.76–2.54)	32	1.59 (1.00–2.52)
Smokers
<10 mg/day	67	6	1.99 (0.81–4.92)	1	0.57 (0.08–4.27)	11	1.81 (0.91–3.57)	1	0.36 (0.05–2.72)	18	2.23 (1.20–4.14)
10–<100 mg/day	311	11	0.87 (0.45–1.71)	16	2.20 (1.16–4.19)	21	0.79 (0.48–1.29)	12	1.03 (0.51–2.08)	81	2.14 (1.49–3.07)
100–<200 mg/day	293	16	1.28 (0.71–2.30)	21	3.27 (1.80–5.94)	41	1.47 (1.00–2.18)	15	1.49 (0.78–2.88)	68	2.26 (1.54–3.31)
200–<300 mg/day	234	14	1.40 (0.75–2.59)	8	1.55 (0.69–3.47)	27	1.17 (0.74–1.84)	9	1.09 (0.50–2.37)	40	1.80 (1.16–2.80)
300+ mg/day	344	19	1.52 (0.87–2.64)	14	1.89 (0.97–3.69)	44	1.19 (0.81–1.73)	12	1.01 (0.50–2.04)	58	2.15 (1.45–3.20)
Folic Acid
<10 mg/day	647	30	1.0	21	1.0	87	1.0	20	1.0	31	1.0
10–<100 mg/day	1189	54	1.04 (0.65–1.67)	45	1.23 (0.72–2.09)	154	1.10 (0.82–1.46)	44	1.20 (0.70–2.07)	103	1.57 (1.01–2.44)
100–<200 mg/day	789	32	0.91 (0.54–1.53)	25	1.01 (0.56–1.85)	125	1.35 (0.99–1.83)	30	1.26 (0.70–2.27)	60	1.62 (1.00–2.63)
200–<300 mg/day	448	22	1.16 (0.65–2.07)	19	1.41 (0.73–2.69)	51	0.90 (0.62–1.31)	23	1.56 (0.83–2.93)	31	1.57 (0.90–2.75)
300+ mg/day	388	23	1.52 (0.85–2.70)	15	1.17 (0.58–2.35)	61	1.27 (0.88–1.82)	17	1.31 (0.67–2.59)	46	2.24 (1.33–3.79)
No Folic Acid
<10 mg/day	477	36	1.34 (0.80–2.24)	11	0.57 (0.27–1.20)	42	0.96 (0.65–1.43)	14	0.98 (0.48–1.99)	72	1.96 (1.22–3.16)
10–<100 mg/day	1187	78	1.10 (0.70–1.73)	55	1.18 (0.69–2.01)	106	1.08 (0.78–1.48)	38	1.05 (0.59–1.85)	155	1.51 (0.98–2.33)
100–<200 mg/day	713	67	1.53 (0.96–2.44)	37	1.36 (0.77–2.40)	75	1.13 (0.80–1.59)	28	1.30 (0.71–2.37)	109	1.96 (1.25–3.09)
200–<300 mg/day	371	32	1.58 (0.92–2.69)	20	1.41 (0.74–2.70)	34	0.94 (0.61–1.45)	17	1.41 (0.72–2.77)	43	1.40 (0.83–2.36)
300+ mg/day	315	23	1.60 (0.90–2.86)	13	1.17 (0.56–2.45)	49	1.52 (1.03–2.24)	13	1.25 (0.60–2.60)	44	1.83 (1.07–3.11)

^*N’s for analyses adjusted for maternal age, race, and state of residence at time of infant’s birth; N’s for analyses with additional covariates may be slightly lower due to missing values for those variables.

^†All odds ratios are adjusted for maternal age, race, and state of residence at time of infant’s birth; medication estimates are also adjusted for intake of coffee, tea, and soda.

^‡Adjusted for maternal alcohol consumption and smoking status.

^§Adjusted for maternal alcohol consumption and body mass index.

^||Adjusted for maternal smoking status and body mass index.

Nonsmokers reporting little or no caffeine intake and those reporting use of folic acid-containing supplements during the month before pregnancy or the first pregnancy month and little or no caffeine intake comprise the referent group for all other strata cross-classified by exposure to caffeine and smoking/folic acid-containing supplement use, respectively.

aOR, adjusted odds ratio, CI, 95% confidence interval.