Table 1. Participants’ basic characteristics.

(n = 13,148)
	Group A: House was not destroyed/did not live in the disaster-affected area (n = 6,838)		Group B: House half-/partly destroyed (n = 4,878)		Group C: House totally/mostly destroyed (n = 1,434)		P
	n	%	n	%	n	%
Age, ≥35 years	1,757	25.8	1,439	29.6	358	25.0	<0.0001
Primiparous	3,424	50.2	2,239	46.0	663	46.4	<0.0001
Pre-pregnancy BMI							0.04
<18.5 kg/m2	1,113	16.3	760	15.6	215	15.0
≥25 kg/m2	706	10.3	552	11.3	186	13.0
Fertility treatments (Yes)	815	12.0	534	11.1	142	10.0	0.047
Multiple pregnancy (Yes)	88	1.9	76	2.3	13	1.4	0.1
Smoking during the first trimester							<0.0001
Current smoker	114	1.7	89	1.8	35	2.5
Stopped after becoming pregnant	735	10.9	590	12.2	224	15.8
Stopped before pregnancy	1,525	22.5	1,226	25.4	350	24.6
Never	4,396	64.9	2,930	60.6	812	57.1
Drinking during the first trimester							0.0006
Current drinker	1,406	20.8	1,034	21.4	235	16.5
Stopped before or during pregnancy	2,321	34.3	1,624	33.6	479	33.7
Never	3,047	45.0	2,181	45.1	707	49.8
Strong activity once or more per week before pregnancy (Yes)	1,067	15.8	787	16.3	240	16.9	0.5
Sleeping pills							0.1
Never use	6,737	99.3	4,807	99.3	1,409	98.9
Less than once per week	13	0.2	6	0.1	1	0.07
Once or more per week	34	0.5	29	0.6	15	1.1
K6 score, ≥13	360	5.3	276	5.7	97	6.8	0.08
Household income (Japanese yen)							<0.0001
<4 million	2,119	32.9	1,627	35.6	591	43.8
≥4 million, <8 million	3,478	53.9	2,328	50.9	626	46.4
≥8 million	854	13.2	618	13.5	133	9.9
Living with Partner	6,274	91.8	4,464	91.5	1,292	90.1	0.1
Living with Maternal parents	537	7.9	544	11.2	182	12.7	<0.0001
Living with Paternal parents	866	12.7	751	15.4	249	17.4	<0.0001
Year of participation							0.01
2013	327	4.8	254	5.2	52	3.6
2014	2,068	30.3	1,606	32.9	475	33.1
2015	2,592	37.9	1,780	36.5	514	35.8
2016	1,841	26.9	1,232	25.3	392	27.3
2017	8	0.1	6	0.1	1	0.07

BMI, body mass index; K6, Kessler 6 Psychological Distress Scale.