Table 5.

Associations between maternal pre-eclampsia and neurodevelopmental disorders in offspring using sibling analyses

Neurodevelopmental disorders	Combined		Denmark		Sweden
	No. of cases	Adjusteda HR (95% CI)	No. of cases	Adjusteda HR (95% CI)	No. of cases	Adjusteda HR (95% CI)
For ADHD
No pre-eclampsia	2170	1.00 (ref)	851	1.00 (ref)	1319	1.00 (ref)
Maternal pre-eclampsia	1746	1.19 (1.11–1.28)	633	1.16 (1.02–1.33)	1113	1.20 (1.08–1.33)
By timing of onset
Early-onset	233	1.54 (1.34–1.77)	129	1.40 (1.14–1.72)	104	1.80 (1.44–2.26)
Late-onset	1513	1.15 (1.07–1.24)	504	1.12 (0.97–1.28)	1009	1.16 (1.05–1.29)
By severity
Moderate	1270	1.16 (1.08–1.25)	483	1.12 (0.98–1.29)	787	1.18 (1.06–1.31)
Severe	476	1.29 (1.16–1.43)	150	1.32 (1.09–1.60)	326	1.26 (1.09–1.46)
For ASD
No pre-eclampsia	1172		540		632	1.00 (ref)
Maternal pre-eclampsia	1076	1.36 (1.24–1.49)	494	1.40 (1.19–1.65)	582	1.29 (1.11–1.49)
By timing of onset
Early-onset	134	1.61 (1.34–1.94)	77	1.41 (1.19–1.66)	57	2.27 (1.68–3.06)
Late-onset	942	1.33 (1.21–1.46)	417	1.38 (1.05–1.80)	525	1.23 (1.06–1.43)
By severity
Moderate	809	1.32 (1.20–1.46)	395	1.37 (1.16–1.62)	414	1.25 (1.07–1.46)
Severe	267	1.49 (1.30–1.72)	99	1.52 (1.20–1.93)	168	1.41 (1.15–1.73)
For ID
No pre-eclampsia	720	1.00 (ref)	322	1.00 (ref)	398	1.00 (ref)
Maternal pre-eclampsia	653	1.43 (1.27–1.61)	254	1.29 (1.04–1.60)	399	1.60 (1.33–1.93)
By timing of onset
Early-onset	150	2.50 (2.07–3.02)	65	2.13 (1.60–2.85)	85	3.26 (2.47–4.31)
Late-onset	503	1.27 (1.12–1.44)	189	1.13 (0.89–1.43)	314	1.42 (1.17–1.72)
By severity
Moderate	439	1.31 (1.15–1.49)	185	1.20 (0.95–1.51)	254	1.45 (1.19–1.78)
Severe	214	1.80 (1.52–2.12)	69	1.59 (1.18–2.15)	145	1.98 (1.57–2.51)

HR hazard ratio, CI confidence interval, ADHD attention-deficit/hyperactivity disorder, ASD autism spectrum disorder, ID intellectual disability

^aAdjusted for sex, calendar year parity, maternal age, maternal education, maternal cohabitation at birth, maternal history of psychiatric disorders before childbirth