Table 4.

Adjusted incidence risk ratios (aIRR) of developing pre-eclampsia during the 2^nd pregnancy according to aspirin use, in women with early and/or severe pre-eclampsia during the 1^st pregnancy

	Mild and late PE during the 2nd pregnancy (N = 1143)		Severe and late PE during the 2nd pregnancy (N = 632)		Mild and early PE during the 2nd pregnancy (N = 209)		Severe and early PE during the 2nd pregnancy (N = 463)		Total PE during the 2nd pregnancy (N = 2,447)
	N	aIRR	N	aIRR	N	aIRR	N	aIRR	N	adjusted IRR
Aspirin purchases
No aspirin	378	Ref	213	Ref	64	Ref	155	Ref	810	Ref
At least one	765	1.06 (0.92–1.22)	419	0.98 (0.82–1.18)	145	0.92 (0.67–1.27)	308	0.77 (0.62–0.95)	1637	0.98 (0.90–1.08)
≤ 16 WG	691	1.04 (0.90–1.20)	365	0.94 (0.78–1.14)	131	0.92 (0.66–1.27)	267	0.71 (0.57–0.89)	1454	0.93 (0.85–1.01)
≤ 16 WG and PDC ≥ 80%	500	1.08 (0.92–1.27)	266	0.96 (0.78–1.19)	91	0.84 (0.59–1.21)	175	0.60 (0.47–0.77)	1032	0.93 (0.86–1.01)
Mean daily dose
No aspirin	378	Ref	213	Ref	64	Ref	155	Ref	810	Ref
0–75 mg/j	213	1.02 (0.86–1.21)	113	0.95 (0.75–1.20)	41	1.04 (0.70–1.55)	108	1.10 (0.85–1.41)	475	1.03 (0.92–1.16)
75–100 mg/j	176	1.05 (0.87–1.26)	98	1.01 (0.79–1.29)	31	0.93 (0.60–1.45)	59	0.77 (0.56–1.04)	364	0.99 (0.87–1.12)
≥ 100 mg/j	376	1.03 (0.88–1.21)	208	0.99 (0.81–1.22)	73	0.86 (0.60–1.23)	141	0.67 (0.53–0.85)	798	0.95 (0.85–1.05)

The IRRs were estimated using Poisson regression models adjusted for the characteristics of the first and second pregnancies. This analysis was performed in women with early and/or severe pre-eclampsia during the 1^st pregnancy, as this was the only indication for aspirin treatment in French guidelines

IRR incidence risk ratio, PDC proportion of days covered (by aspirin), PE pre-eclampsia, WG weeks of gestation