Table 3.

Odds Ratios and 95% Confidence Intervals for Birth Characteristics and Risk of Pediatric Thyroid Cancer in Cases and Controls Born in California, 1978–2011, Stratified by Ethnicity

	White (n = 380 cases, 7141 controls)		Hispanic (n = 480 cases, 10,985 controls)
	OR	[CI]	OR	[CI]
Sex
Female	1.00		1.00
Male	0.22	[0.17–0.28]	0.23	[0.18–0.29]
Birth weight (per 500 g)	1.16	[1.04–1.29]	1.05	[0.96–1.15]
Gestational age (weeks)
22–36	1.21	[0.80–1.85]	1.26	[0.92–1.73]
37–41	1.00		1.00
42–44	0.85	[0.59–1.22]	0.83	[0.58–1.17]
Unknown	0.92	[0.59–1.45]	1.07	[0.73–1.57]
Maternal age (years)
<20	0.86	[0.45–1.64]	0.61	[0.42–0.90]
20–24	1.04	[0.74–1.45]	0.90	[0.69–1.16]
25–29	1.00		1.00
30–34	0.83	[0.62–1.12]	0.87	[0.64–1.16]
≥35	0.92	[0.62–1.36]	0.75	[0.55–1.12]
Maternal education (years)
<12	0.70	[0.37–1.31]	0.82	[0.62–1.08]
12	1.00		1.00
13–15	1.18	[0.82–1.71]	1.58	[1.15–2.16]
16+	1.33	[0.92–1.92]	1.60	[1.04–2.45]
Unknown	0.91	[0.52–1.58]	1.20	[0.75–1.92]
Mother's place of birth
United States	1.00		1.00
Foreign	1.25	[0.90–1.73]	1.05	[0.86–1.29]
Paternal age (years)
<25	0.66	[0.42–1.04]	1.07	[0.77–1.49]
25–29	0.92	[0.68–1.25]	1.06	[0.80–1.41]
30–34	1.00		1.00
35–39	1.09	[0.79–1.51]	1.29	[0.91–1.83]
≥40	1.10	[0.73–1.66]	1.09	[0.69–1.73]
Unknown	0.75	[0.37–1.51]	0.78	[0.47–1.29]
Birth order
First	1.00		1.00
Second	1.00	[0.78–1.29]	0.80	[0.63–1.02]
Third+	0.95	[0.70–1.29]	0.73	[0.56–0.96]
Mode of delivery
Vaginal	1.00		1.00
C-section	1.14	[0.86–1.51]	0.89	[0.67–1.17]
Miscarriage/stillbirth
Never	1.00		1.00
Ever	1.17	[0.90–1.51]	1.02	[0.79–1.33]
Maternal pregnancy complication
Never	1.00		1.00
Ever	1.12	[0.83–1.50]	0.79	[0.58–1.06]
Unknown	1.10	[0.30–4.06]	2.59	[0.51–13.05]
Previous C-section
Never	1.00		1.00
Ever	0.87	[0.56–1.35]	1.11	[0.74–1.65]
Unknown	0.73	[0.19–2.79]	0.44	[0.07–2.65]

Regression models are multivariable models with all variables listed in table included.