Table 1.

Incidence of Autism Spectrum Disorder starting at 1 year of age according to defective placentation syndromes. Live-born singleton non-malformed children in Sweden 2000–2016.

Defective placentation syndrome	General cohort			Sibling cohort
	Number of children	No. with autism	Rate per 10,000 child-years	Number of children	No. with autism	Rate per 10,000 child-years
Total	1,645,455	23,810	16.17	1,092,132	14,483	14.66
Placental abruption
No	1,640,167	23,684	16.14	1,088,931	14,411	14.64
Yes	5288	126	25.61	3201	72	24.35
Preeclampsia
No preeclampsia	1,601,162	22,862	15.96	1,066,542	13,949	14.49
Preeclampsia at ≥37 weeks without SGA1	30,163	555	20.45	17,922	320	18.51
Preeclampsia at ≥37 weeks with SGA	4914	129	29.23	2674	79	30.10
Preeclampsia at 34 to 36 weeks	5660	140	26.88	3190	74	24.06
Preeclampsia at <34 weeks	3441	122	37.54	1739	61	35.31
Missing	115	2	15.84	65	0
Gestational age2
Term	1,571,286	22,204	15.81	1,047,369	13,590	14.38
Moderately preterm spontaneous	47,419	801	18.35	29,877	462	16.21
Very/extremely preterm spontaneous	5026	206	45.89	2784	115	44.69
Moderately preterm medically indicated	16,619	387	26.03	9429	211	24.87
Very/extremely preterm medically indicated	3281	137	45.92	1666	67	43.03
Missing	1824	75	33.45	1007	38	31.82

¹Birth weight-for-gestational age <10^th percentile.

²Term: ≥37 weeks. Moderately preterm: 32 to 36 weeks. Very/extremely preterm: 22 to 31 weeks.