Table 1

Rates of pregnancy complications in second pregnancy by maternal characteristics

	Adverse outcomes second pregnancy
		Pre-eclampsia
		Term (<37 weeks)		Preterm (<37 weeks)		Small for gestational age *
Maternal characteristics	Total number	Number	Rate (%)	Number	Rate (%)	Number	Rate (%)
Partner
Same	409922	4779	1.17	958	0.23	22984	5.9
Different	30400	417	1.37	133	0.44	2348	8.2
Data missing	6137	105	1.71	33	0.54	389	9.3
Year of first birth
1990–1994	187733	2224	1.18	384	0.20	11869	6.7
1995–1999	137445	1760	1.28	438	0.32	7904	6.2
2000–2006	121281	1317	1.09	302	0.25	5948	5.2
Interpregnancy interval (years)
<1	84268	753	0.89	110	0.13	4914	6.2
1–3.9	305769	3614	1.18	698	0.23	16799	5.8
4–6.9	41681	675	1.62	207	0.50	2837	7.3
7–9.9	10773	166	1.54	77	0.71	821	8.1
≥10	3727	87	2.33	30	0.80	325	9.3
Data missing	241	6	2.49	2	0.83	25	14.0
Age second pregnancy (years)
<25	60195	585	0.97	109	0.18	4342	7.7
25–29.9	165336	1872	1.13	332	0.20	9152	5.9
30–34.9	160041	1942	1.21	457	0.29	8601	5.7
≥35	60887	902	1.48	226	0.37	3626	6.4
Body mass index second pregnancy (kg/m²)
<18.5	9655	48	0.50	18	0.19	1284	13.9
18.5–24.9	242986	1915	0.79	476	0.20	15032	6.5
≥25	125646	2569	2.04	444	0.35	5354	4.6
Data missing	68172	767	1.13	186	0.27	4051	6.3
Height (cm)
<162	88848	1134	1.28	301	0.34	8184	9.9
162–171	253815	3003	1.18	615	0.24	13653	5.7
≥172	94122	1063	1.13	186	0.20	3213	3.6
Data missing	9674	101	1.10	22	0.23	671	7.3
Smoking habits second pregnancy
Non-smoker	375372	4646	1.24	924	0.25	18766	5.3
Smoker	45091	354	0.79	77	0.17	5491	12.8
Data missing	25996	301	1.16	123	0.47	1464	6.0
Involuntary childlessness second pregnancy (years)
<1	427908	4958	1.16	1025	0.24	24615	6.1
1–2	12080	209	1.73	48	0.40	728	6.5
≥3	5441	121	2.22	38	0.70	378	7.6
Data missing	1030	13	1.26	13	1.26	0
Mother's country of birth
Nordic	394349	4903	1.24	981	0.25	20875	5.6
Non-Nordic	48097	370	0.77	129	0.27	4442	9.7
Data missing	4013	28	0.70	14	0.35	404	10.5
Education (years)
<13	130901	1809	1.38	342	0.26	8951	7.3
13–14	177302	2171	1.22	449	0.25	8903	5.4
≥15	102759	1064	1.04	237	0.23	4577	4.7
Data missing	35497	257	0.72	96	0.27	3290	9.8
Total	446459	5301	1.19	1124	0.25	25721	6.1