Table 5.

Odds ratios (ORs)^a for thyroid cancer risk in offspring (papillary, n=1,968 and follicular, n=280) in relation to maternal and neonatal characteristics, stratified on age at diagnosis.

	Papillary				Follicular
	<30 years		30+ years		<30 years		30+ years
	OR1	95%	OR1	95%	OR1	95%	OR1	95%
Maternal characteristics
Age at birth (per birth)	0.99	0.98-1·00	1·00	0.99-1·01	0.97	0.94-1·01	0.98	0.95-1·02
Smoking during pregnancy (yes vs. no)	1·14	0.89-1·47	0.29	0.03-2·66	0.98	0.52-1·86	7·94	0.49-128
Marital status
Married/ cohabitant	1·00	Reference	1·00	Reference	1·00	Reference	1·00	Reference
Single/widow/divorced/other	1·08	0.91-1·28	1·00	0.82-1·21	0.83	0.52-1·33	0.98	0.59-1·63
Paternal characteristics
Age at birth (per year)	1·00	0.98-1·02	1·00	0.98-1·01	0.99	0.94-1·04	0.97	0.93-1·01
Birth characteristics
Preterm birth (yes vs. no)	1·04	0.78-1·37	0.69	0.46-1·04	1·06	0.50-2·22	1·36	0.63-2·93
Multiple birth (yes vs. no)	1·18	0.77-1·81	1·32	0.83-2·12	0.33	0.04-2·43	1·00	0.23-4·31
Cesarean delivery (yes vs. no)	0.90	0.72-1·13	0.94	0.69-1·27	1·09	0.63-1·88	1·63	0.78-3·38
Small-for-gestational age (yes vs. no)	1·22	0.86-1·75	0.94	0.62-1·43	0.28	0.04-2·06	0.80	0.24-2·64
Large-for-gestational age (yes vs. no)	1·26	0.84-1·88	1·23	0.78-1·92	0.59	0.18-1·95	0.48	0.06-3·59
Birth weight (g)
<1,500	1·15	0.46-2·91	NE	NE	NE	NE	NE	NE
1,500-2,499	1·09	0.78-1·51	0.90	0.61-1·33	1·22	0.47-3·15	0.59	0.18-1·96
2,500-3,499	1·00	Reference	1·00	Reference	1·00	Reference	1·00	Reference
3,500-4,499	1·15	1·01-1·31	1·01	0.87-1·16	1·61	1·13-2·28	1·41	0.97-2·06
4,500+	1·30	0.87-1·93	1·31	0.87-1·97	1·00	0.35-2·90	NE	NE
Birth weight (per kg)	1·11	0.99-1·25	1·11	0.97-1·26	1·44	1·06-1·97	1·31	0.92-1·88
Birth order
1	1·00	Reference	1·00	Reference	1·00	Reference	1·00	Reference
2	0.99	0.86-1·14	1·03	0.88-1·20	1·21	0.83-1·75	0.84	0.55-1·27
3	0.78	0.65-0.95	0.89	0.72-1·09	0.89	0.53-1·49	0.78	0.46-1·33
4	0.78	0.57-1·07	0.70	0.49-1·00	0.68	0.29-1·64	0.72	0.30-1·75
5+	1·33	0.93-1·91	0.71	0.46-1·11	0.46	0.11-1·95	0.57	0.17-1·92
Maternal conditions diagnosed before pregnancy
Diabetes (yes vs. no)	2·25	1·09-4·63	0.91	0.27-2·99	1·11	0.14-8·77	20.0	1·81-221
Hypertension (yes vs. no)	0.58	0.08-4·39	5·00	0.45-55·1	NE	NE	NE	NE
Maternal conditions diagnosed before/during pregnancy (Denmark only)
Hypothyroidism (yes vs. no)	42·5	17·5-103	12·2	4·88-30.7	5·00	0.45-55·1	NE	NE
Hyperthyroidism (yes vs. no)	9·63	3·99-23·2	14·4	6·17-33·8	NE	NE	8·22	1·13-60.1
Goiter (yes vs. no)	48·7	22·8-104	77·8	30.7-197	28·4	7·66-105	NEb	NEb
Thyroiditis (yes vs. no)	2·50	0.28-22·5	5·00	0.92-27·3	NE	NE	NE	NE
Benign neoplasms (yes vs. no)	20.0	3·66-109	20.0	1·81-221	NE	NE	10.0	0.63-160
Maternal conditions diagnosed during pregnancy
Gestational hypertension (yes vs. no)	0.74	0.43-1·28	0.62	0.30-1·26	NE	NE	2·53	0.84-7·67
Hyperemesis (yes vs. no)	1·02	0.51-2·03	1·02	0.44-2·36	2·20	0.61-7·87	1·00	0.13-7·81
Pregnancy anemia (yes vs. no)	1·39	0.77-2·51	0.58	0.23-1·43	0.83	0.10-6·55	1·43	0.18-11·6
Gestational diabetes (yes vs. no)	1·19	0.47-3·05	1·25	0.16-9·99	2·27	0.48-10.8	NE	NE
Placental abruption (yes vs. no)	0.69	0.21-2·25	0.65	0.15-2·70	1·46	0.17-12·8	NE	NE
Placenta previa (yes vs. no)	1·07	0.32-3·54	0.74	0.17-3·13	NE	NE	1·67	0.20-13·8
Preeclampsia/eclampsia (yes vs. no)	1·00	0.68-1·47	1·01	0.63-1·63	0.33	0.04-2·42	1·44	0.50-4·19
Postpartum hemorrhage (yes vs. no)	1·15	0.86-1·54	1·27	0.93-1·74	1·63	0.78-3·37	1·78	0.88-3·59
Neonatal conditions diagnosed in the first year after birth
Congenital hypothyroidism (yes vs. no)	2·86	0.59-13·8	NE	NE	20.0	1·81-221	NE	NE
Neonatal jaundice (yes vs. no)	1·36	0.85-2·18	1·05	0.25-4·52	0.37	0.05-2·79	NE	NE

^aFrom conditional logistic regression models, conditioned on birth year (of the case), sex, country, and county of birth

^bIn unconditional logistic regression models (adjusting for the matching factors), the OR is 216 (95% CI 87-541), based on 19 exposed cases (59%) and 3 exposed controls (1%)