Table 3.

Unadjusted Association of Risk of Select Birth Defects with Maternal Alcohol Consumption during the First Month of Pregnancy

	Number of drinking days per week			Binge drinkingb
	0	<1	≥1
All conotruncal heart defects (n=247)
Cases	186	42	19	12
Controls	425	66	49	28
OR [95% CI]a	Reference	1.5 [1.0, 2.2]	0.9 [0.5, 1.5]	1.0 [0.5, 2.0]
dTGA (n=106)
Cases	76	22	8	6
Controls	425	66	49	28
OR [95% CI]a	Reference	1.9 [1.1, 3.2]	0.9 [0.4, 2.0]	1.2 [0.5, 3.0]
TOF (n=141)
Cases	110	20	11	6
Controls	425	66	49	28
OR [95% CI]a	Reference	1.2 [0.7, 2.0]	0.9 [0.4, 1.7]	0.8 [0.3, 2.0]
All NTDs (n=261)
Cases	201	34	26	8
Controls	381	58	43	25
OR [95% CI]a	Reference	1.1 [0.7, 1.8]	1.1 [0.7, 1.9]	0.6 [0.3, 1.4]
Anencephaly (n=116)
Cases	91	13	12	3
Controls	381	58	43	25
OR [95% CI]a	Reference	0.9 [0.5, 1.8]	1.2 [0.6, 2.3]	0.5 [0.1, 1.7]
Spina Bifida (n=145)
Cases	110	21	14	5
Controls	381	58	43	25
OR [95% CI]a	Reference	1.3 [0.7, 2.2]	1.1 [0.6, 2.1]	0.7 [0.3, 1.9]
Isolated CP (n=107)
Cases	81	17	9	1
Controls	381	58	43	25
OR [95% CI]a	Reference	1.4 [0.8, 2.5]	1.0 [0.5, 2.1]	N/Ac
Multiple CP (n=34)
Cases	26	5	3	1
Controls	381	58	43	25
OR [95% CI]a	Reference	1.3 [0.5, 3.4]	1.0 [0.3, 3.5]	N/Ac
Isolated CLP (n=340)
Cases	265	44	31	19
Controls	381	58	43	25
OR [95% CI]a	Reference	1.1 [0.7, 1.7]	1.0 [0.6, 1.7]	1.1 [0.6, 2.0]
Multiple CLP (n=43)
Cases	27	8	8	4
Controls	381	58	43	25
OR [95% CI]a	Reference	1.9 [0.8, 4.5]	2.6 [1.1, 6.1]	2.3 [0.7, 7.0]

OR, odds ratio; CI: confidence interval; dTGA, d-transposition of the great arteries; TOF, Tetralogy of Fallot; NTD, neural tube defects; CP, cleft palate; CLP, cleft lip with or without cleft palate.

^aThe reference group includes women who reported no smoking and no alcohol consumption during the entire periconceptional period.

^bBinge drinking is defined as consuming five or more drinks per drinking occasion.

^cThe OR was not estimated if the number of exposed cases was less than or equal to one.