Table 1.

Maternal characteristics at the time of pregnancy by exposure groups

Hyperthyroidism before/during the pregnancy		Hyperthyroidism 0 – 2 years after the pregnancy		No hyper- or hypothyroidism up to 2 years after the pregnancy
n	%	n	%	n	%
Pregnancies	5,229	–	2,361	–	829,315	–
Age
<25 years	297	5.7	289	12.2	113,069	13.6
25 – 29 years	1,373	26.3	745	31.6	281,633	34.0
30 – 34 years	2,014	38.5	839	35.5	288,663	34.8
35 – 39 years	1,265	24.2	408	17.3	121,622	14.7
≥40 years	280	5.3	80	3.4	24,328	2.9
Paritya
1	2,211	42.3	1,373	58.2	449,232	54.2
2	1,798	34.4	631	26.7	250,609	30.2
3	796	15.2	243	10.3	91,043	11.0
≥4	424	8.1	114	4.8	38,431	4.6
Cohabitation
Married	3,173	60.7	1,282	54.3	470,246	56.7
Not married	2,056	39.3	1,079	45.7	359,069	43.3
Income, quartiles
1st (lowest)	254	4.9	139	5.9	49,474	6.0
2nd	1,760	33.6	810	34.3	267,525	32.3
3rd	2,347	44.9	1,057	44.8	375,147	45.2
4th	868	16.6	355	15.0	137,169	16.5
Origin
Born in Denmark	4,544	86.9	1,998	84.6	732,396	88.3
Not born in Denmark	685	13.1	363	15.4	96,919	11.7
Residence
West Denmark	2,800	53.5	1,297	54.9	448,465	54.1
East Denmark	2,429	46.5	1,064	45.1	380,850	45.9

^aPrevious pregnancies in the study period including index pregnancy.