TABLE 1.

Characteristics of control mothers by report of benzodiazepine medication use any time during the month before through the end of pregnancy, National Birth Defects Prevention Study, 1997–2011

	No benzodiazepine exposure		Any benzodiazepinea			Alprazolam			Clonazepam			Diazepam			Lorazepam
	N	%	N	%	p-value	N	%	p-value	N	%	p-value	N	%	p-value	N	%	p-value
Totalb	11,521		93	0.8		43	0.4		22	0.2		21	0.2		10	0.1
Age group (years)
12–17	584	5.1	2	2.2	0.004	1	2.3	0.416	1	4.5	0.069	1	4.8	0.272	0	0.0	0.274
18–29	6,842	59.4	43	46.2		23	53.5		8	36.4		9	42.9		4	40.0
≥30	4,095	35.5	48	51.6		19	44.2		13	59.1		11	52.4		6	60.0
Race/ethnicity
Non-Hispanic white	6,676	58.0	77	82.8	<0.001	38	88.4	<0.001	19	86.4	0.061	17	81.0	0.182	6	60.0	0.112
Non-Hispanic black	1,260	10.9	4	4.3		0	0.0		1	4.5		1	4.8		2	20.0
Hispanic	2,825	24.5	7	7.5		2	4.7		2	9.1		3	14.3		0	0.0
Other race/ethnicity	754	6.6	5	5.4		3	7.0		0	0.0		0	0.0		2	20.0
Maternal education (years)
<12	1,899	16.7	5	5.4	<0.001	4	9.5	0.092	1	4.5	0.187	0	0.0	0.018	0	0.0	0.300
12	2,711	23.8	14	15.2		6	14.3		4	18.2		2	10.0		2	20.0
>12	6,781	59.5	73	79.3		32	76.2		17	77.3		18	90.0		8	80.0
Body mass index category
Underweight (<18.5 kg/m2)	586	5.3	7	7.6	0.434	2	4.7	0.700	3	13.6	0.058	1	5.0	0.797	1	10.0	0.426
Normal weight (18.5–24.9 kg/m2)	5,925	53.7	43	46.7		24	55.8		6	27.3		11	55.0		3	30.0
Overweight (25.0–29.9 kg/m2)	2,506	22.7	21	22.8		7	16.3		7	31.8		3	15.0		4	40.0
Obese (≥30 kg/m2)	2,022	18.3	21	22.8		10	23.3		6	27.3		5	25.0		2	20.0
Smoking during pregnancyc
Any	2,064	18.1	30	32.6	<0.001	20	47.6	<0.001	4	18.2	0.999	4	20.0	0.832	3	30.0	0.332
None	9,368	82.0	62	67.4		22	52.4		18	81.8		16	80.0		7	70.0
Year of estimated date of delivery
1997–1999d	1,696	14.7	15	16.1	0.685	5	11.6	0.571	2	9.1	0.113	6	28.6	0.409	2	20.0	0.378
2000–2001	1,680	14.6	8	8.6		4	9.3		2	9.1		1	4.8		0	0.0
2002–2003	1,572	13.6	12	12.9		8	18.6		3	13.6		1	4.8		0	0.0
2004–2005	1,722	15.0	18	19.4		9	20.9		3	13.6		4	19.0		3	30.0
2006–2007	1,659	14.4	15	16.1		8	18.6		2	9.1		4	19.0		3	30.0
2008–2009	1,634	14.2	12	12.9		6	14.0		2	9.1		3	14.3		1	10.0
2010–2011	1,558	13.5	13	14.0		3	7.0		8	36.4		2	9.5		1	10.0
Antidepressant medication use during pregnancyc
Any	528	4.6	38	40.9	<0.001	17	39.5	<0.001	14	63.6	<0.001	6	28.6	<0.001	5	50.0	<0.001
None	10,985	95.4	55	59.1		26	60.5		8	36.4		15	71.4		5	50.0
Antiepileptic medication use during pregnancyc,e
Any	67	0.6	3	3.2	0.005	1	2.3	0.343	0	0.0	0.935	1	4.8	0.048	1	10.0	<0.001
None	11,453	99.4	90	96.8		42	97.7		22	100.0		20	95.2		9	90.0

^aSix mothers reported use of two different benzodiazepines during the month before pregnancy; this category includes exposures to chlorazepate dipotassium, triazolam, and oxazepam, each reported only once.

^bRow percentages are presented for the total; otherwise, column percentages are presented. Numbers may not add up to the total due to missing values.

^cDefined as the month before through the end of pregnancy.

^d1997 was a partial year of eligibility corresponding to the beginning of the study period (October 1).

^eExcluding benzodiazepines.