Table 3.

Incidence rate ratios of being treated with aspirin during the second pregnancy, in women with pre-eclampsia during their first pregnancy

	At least one aspirin dispensing		IRR (95% CI) of receiving aspirin during the second pregnancy
	N	%	Crude	Fully-adjusted
According to the characteristics at the beginning of the 2nd pregnancy
Maternal age
< 20 years	76	19.7	0.49 (0.39–0.61)	0.60 (0.48–0.75)
[20–30]	5273	40.2	Ref	Ref
[30–40]	6660	47.2	1.18 (1.13–1.22)	1.13 (1.09–1.17)
≥ 40 years	390	46.6	1.16 (1.05–1.29)	1.08 (0.97–1.19)
Social deprivation	1693	33.7	0.74 (0.70–0.78)	0.74 (0.70–0.78)
Obesity	1392	41.8	0.96 (0.90–1.01)	0.96 (0.91–1.02)
Diabetes	231	46.6	1.07 (0.94–1.22)	1.01 (0.89–1.15)
Tobacco use	1067	44.6	1.03 (0.96–1.09)	1.03 (0.96–1.09)
Chronic HT	2938	55.1	1.35 (1.29–1.40)	1.16 (1.11–1.21)
Multiple pregnancy	295	32.2	0.73 (0.65–0.82)	0.67 (0.59–0.75)
Gestational diabetes	1101	39.0	0.88 (0.83–0.94)	0.92 (0.86–0.98)
Gestational hypertension	1551	46.8	1.08 (1.03–1.14)	0.93 (0.88–0.98)
Mild and late PE	4341	27.8	Ref	Ref
Severe and late PE	4161	54.2	1.95 (1.87–2.04)	1.94 (1.86–2.03)
Mild and early PE	857	63.9	2.30 (2.14–2.48)	2.34 (2.17–2.52)
Severe and early PE	3040	79.9	2.88 (2.75–3.01)	2.87 (2.74–3.01)

CI confidence interval, HT hypertension, IRR incidence risk ratio, PE pre-eclampsia

^*Adjusted for all characteristics of the first pregnancy and the characteristics at the beginning of the second pregnancy