Assessing the role of multiple pregnancies in the association between tetralogy of Fallot and assisted reproductive techniques: a path-analysis approach

Table 1 Associations between predictor variables and case/control status

Characteristics		TOF (N=404)		Controls (N=4 250)		p
		n*	%^§	n*	%^§
Mother	Age (years)
	Mean (SD)	31.7 (5.6)		30.4 (5.2)		<0.001
	Median (p25-p75)	31.5 (28 – 36)		30 (27 – 34)
	<20	3	0.8	59	1.4	<0.001
	20 – 29	146	36.5	1,809	42.8
	30 – 34	126	31.5	1,434	33.9
	35 – 39	91	22.8	722	17.1
	≥ 40	34	8.5	203	4.8
	Geographic origin
	France	200	50.4	2,412	57.9	<0.001
	North Africa	72	18.1	433	10.4
	Subsaharan Africa	39	9.8	550	13.2
	Other	86	21.7	770	18.5
	Occupation
	None	113	30.9	1,083	26.3	0.096
	Professional	84	23.0	997	24.2
	Intermediate	64	17.5	856	20.8
	Administrative/public service	67	18.3	852	20.7
	Other	38	10.4	330	8.0
Father	Age (years)
	Mean (SD)	35.0 (6.6)		33.9 (6.6)		0.006
	Median (p25-p75)	34 (30 – 39)		33 (29 – 38)
	<20	1	0.3	5	0.1	0.014
	20 – 29	59	19.5	890	25.8
	30 – 34	94	31.1	1,198	34.7
	35 – 39	79	26.2	734	21.3
	≥ 40	69	22.9	734	21.3
	Geographic origin
	France	179	49.2	2,325	58.6	<0.001
	North Africa	66	18.1	416	10.5
	Subsaharan Africa	38	10.4	529	13.3
	Other	81	22.3	700	17.6
	Occupation
	None	24	7.6	281	7.4	0.014
	Professional	110	34.6	1,474	38.6
	Intermediate	44	13.8	566	14.8
	Administrative/public service	28	8.8	479	12.5
	Other	112	35.2	1,020	26.7
Pregnancy	Outcome
	Still-births	18	4.5	7	0.2	<0.001
	Live-births	269	66.6	4,231	99.6
	Pregnancy terminations	117	29.0	12	0.3
Art	None	369	93.4	3,959	96.5	0.004
	IO^$ only	11	2.8	77	1.9
	IVF^£ only	10	2.5	55	1.3
	IVF+ICSI^¥	5	1.3	13	0.3

^*n represents the number of cases or controls without missing data.
^§% calculated with the number of cases or controls without missing data as a denominator.
^$Inductors of ovulation.
^£In vitro fertilization.
^¥IVF with intracytoplasmic sperm injection.

ISSN: 1750-1172