Table 1.

Distribution of recognized risk factors for HLHS and TOF among cases and controls in the NBDPS, 1997–2011

Risk factors	Controls (n = 11,829)*		HLHS (n = 594)			TOF (n = 971)
	N	%	N	%	Crude OR (95% CI)	N	%	Crude OR (95% CI)
Maternal race
Non-Hispanic White	6836	57.8	384	64.7	1.3 (1.1–1.6)	549	56.5	0.9 (0.8–1.1)
Other	4986	42.2	210	35.4	Ref	422	43.5	Ref
Missing	7	0.1
Male sex
Yes	6024	50.9	399	67.2	2.0 (1.7–2.4)	558	57.5	1.3 (1.1–1.5)
No	5793	49.0	193	32.5	Ref	412	42.4	Ref
Missing	12	0.1	2	0.3		1	0.1
Nulliparous†
Yes	3471	29.3	150	25.3	0.8 (0.7–1.0)	303	31.2	1.1 (0.9–1.3)
No	8307	70.2	441	74.2	Ref	665	68.5	Ref
Missing	51	0.4	3	0.5		3	0.3
Maternal age (y)
≥35	1664	14.1	83	14.0	1.0 (0.8–1.3)	182	18.7	1.4 (1.2–1.7)
<35	10,165	85.9	511	86.0	Ref	789	81.3	Ref
First-degree family history of CHD
Yes	139	1.2	31	5.2	4.6 (3.1–6.9)	50	5.2	4.6 (3.3–6.4)
No	11,690	98.8	563	94.8	Ref	921	94.9	Ref
Pregestational diabetes‡
Yes	74	0.6	12	2.0	3.3 (1.8–6.1)	27	2.8	4.6 (2.9–7.1)
No	11,676	98.7	579	97.5	Ref	936	96.4	Ref
Missing	79	0.7	3	0.5		8	0.8
Prepregnancy overweight–obesity††
Yes	4631	39.1	255	42.9	1.2 (1.0–1.4)	437	45.0	1.3 (1.1–1.4)
No	6644	56.2	311	52.4	Ref	497	51.2	Ref
Missing	554	4.7	28	4.7		37	3.8
Periconceptional opioid use§
Yes	246	2.1	26	4.4	2.2 (1.4–3.2)	31	3.2	1.6 (1.1–2.3)
No	11,364	96.1	559	94.1	Ref	923	95.1	Ref
Missing	219	1.9	9	1.5		17	1.8
First-trimester oral contraceptive use||
Yes	377	3.2	25	4.2	1.3 (0.9–2.0)	30	3.1	1.0 (0.7–1.4)
No	11,393	96.3	565	95.1	Ref	937	96.5	Ref
Missing	59	0.5	4	0.7		4	0.4
Periconceptional trimethoprim–sulfamethoxazole or nitrofurantoin§
Yes	190	1.6	16	2.7	1.7 (1.0–2.8)	18	1.9	1.2 (0.7–1.9)
No	11,622	98.3	577	97.1	Ref	950	97.8	Ref
Missing	17	0.1	1	0.2		3	0.3
Periconceptional selective serotonin reuptake inhibitor use§
Yes	378	3.2	28	4.7	1.5 (1.0–2.2)	50	5.2	1.6 (1.2–2.2)
No	11,269	95.0	559	94.1	Ref	905	93.2	Ref
Missing	215	1.8	7	1.2		16	1.7
Assisted reproductive technology or clomiphene citrate for help becoming pregnant¶
Yes	336	2.8	22	3.7	1.3 (0.8–2.0)	42	4.3	1.5 (1.1–2.1)
No	11,427	96.6	569	95.8	Ref	926	95.4	Ref
Missing	66	0.6	3	0.5		3	0.3
Periconceptional fever#
Yes	1296	11.0	76	12.8	1.2 (1.0–1.6)	112	11.5	1.1 (0.9–1.3)
No	9466	80.0	453	76.3	Ref	760	78.3	Ref
Missing	1067	9.0	65	10.9		99	10.2
Periconceptional smoking**
Yes	2075	17.5	98	16.5	0.9 (0.7–1.2)	155	16.0	0.9 (0.7–1.1)
No	9454	79.9	485	81.7	Ref	793	81.7	Ref
Missing	300	2.5	11	1.9		23	2.4
Periconceptional alcohol**
Yes	4280	36.2	201	33.8	0.9 (0.7–1.1)	365	37.6	1.1 (0.9–1.2)
No	7210	61.0	383	64.5	Ref	574	59.1	Ref
Missing	339	2.9	10	1.7		32	3.3

Bolded text indicates significant at P < .05.

^*The total number of controls was 11,829; 10,061 controls were included in the HLHS analysis, and 10,077 controls were included in the TOF analysis because of missing values for included variables.

^†No previous pregnancies.

^‡Type I diabetes diagnosed any time or type II diabetes diagnosed before the pregnancy.

^§Any reported use between the month before through the third month of pregnancy.

^||Any reported use between the first through the third month of pregnancy.

^¶Use of intracytoplasmic sperm injection, in vitro fertilization, gamete intrafallopian transfer, zygote intrafallopian transfer, or clomiphene citrate.

^#Maternal report of fever in the month before through the third month of pregnancy.

^**Maternal report in the month before through the third month of pregnancy.

^††Body mass index ≥ 25 kg/m².