Table 5.

Perinatal factors (birth weight, gestational age, congenital malformation, spontaneous abortion and use of fertility treatments) and neuroblastoma: analyses stratified by age

	Children < 1 year				Children > 1 year
	Cases (n=74)	Controls (n=187)	OR1	95% CI2	Cases (n=117)	Controls (n=1494)	OR	95% CI
Birth weight in quintiles (gram)
<2930	19	31	4.8	(1.6–15)	31	303	1.0	(0.5–1.8)
2930–3199	15	38	2.3	(0.8–6.8)	14	278	0.5	(0.3–1.0)
3200–3449	7	45	1.0	reference	28	308	1.0	reference
3450–3719	12	30	3.0	(1.0–9.4)	18	308	0.6	(0.3–1.1)
≥3720	20	43	2.9	(1.0–8.0)	26	296	0.9	(0.5–1.7)
Birth weight (gram)
<2500	4	13	1.3	(0.3–5.5)	11	81	1.9	(0.8–4.9)
2500–2999	18	28	2.9	(1.2–6.9)	21	276	1.0	(0.5–1.7)
3000–3499	19	77	1.0	reference	43	594	1.0	reference
3500–3999	23	51	2.0	(0.9–4.4)	30	413	0.9	(0.6–1.6)
≥4000	9	18	2.7	(0.9–7.7)	12	129	1.3	(0.7–2.6)
Gestational age (week)
<37	6	13	0.9	(0.2–3.4)	11	98	1.0	(0.5–2.3)
37–39	31	71	1.3	(0.7–2.6)	30	422	0.8	(0.5–1.3)
40–41	36	100	1.0	reference	72	922	1.0	reference
>41	1	3	0.9	(0.1–11)	2	37	0.8	(0.2–3.4)
Congenital malformations
No	67	158	1.0	reference	112	1439	1.0	reference
Yes	7	2	16.8	(3.1–90)	5	55	1.0	(0.3–2.9)
minor	0	1	-	-	2	18	1.9	(0.4–8.6)
major	7	1	31.3	(3.6–272)	3	37	0.7	(0.2–3.0)
Spontaneous abortions
No	66	144	1.0	reference	94	1095	1.0	reference
Yes	8	43	0.4	(0.1–0.8)	23	399	0.7	(0.4–1.1)
Use of fertility treatments (index child)
No	72	177	1.0	reference	110	1422	1.0	reference
Yes	2	10	0.5	(0.1–2.3)	7	72	1.2	(0.5–2.7)

¹Odds ratios adjusted for age and gender;

²95% CI: 95% Confidence Interval