Table 4.

Maternal characteristics and clinical risk factors associated with preeclampsia

	Incidence rate per 1000 births (95%CI)		Crude Relative risk (95%CI)		P Value	Adjusted Relative risk (95%CI)a		P Value
Age at delivery
15–24	7.19	(6.96–7.42)	Reference			Reference
25–34	10.77	(10.6–10.9)	1.48	(1.43–1.54)	< 0.01*	1.49	(1.44-1.55)	< 0.01*
35–55	20.78	(20.3–21.2)	2.78	(2.67–2.89)	< 0.01*	2.62	(2.51-2.73)	< 0.01*
Number of prior ≧20 weeks births (parity)
0	12.63	(12.5–12.8)	1.35	(1.32–1.38)	< 0.01*	1.71	(1.67-1.76)	< 0.01*
≥ 1	9.2	(9.00-9.39)	Reference			Reference
Acute Coronary syndromeb
No	11.48	(11.4–11.6)	Reference			Reference
Yes	22.28	(18.4–26.1)	1.93	(1.60–2.31)	< 0.01*	0.9	(0.74-1.10)	0.32
Chronic ischemic heart disease
No	11.45	(11.3–11.6)	Reference			Reference
Yes	33.31	(28.9–37.7)	2.83	(2.46–3.27)	< 0.01*	0.9	(0.77-1.06)	0.21
Stroke
No	11.46	(11.3–11.6)	Reference			Reference
Yes	28.12	(24.0–32.3)	2.44	(2.09–2.85)	< 0.01*	1.33	(1.13-1.58)	< 0.01*
Diabetes mellitus
No	11.12	(11.0–11.2)	Reference			Reference
Yes	51.24	(48.5–53.9)	4.28	(4.02–4.55)	< 0.01*	2.01	(1.86-2.16)	< 0.01*
Chronic hypertension
No	10.29	(10.2–10.4)	Reference			Reference
Yes	197.56	(191–204)	15.5	(14.8–16.2)	< 0.01*	12.14	(11.5-12.8)	< 0.01*
Hyperthyroidism
No	11.34	(11.2–11.5)	Reference			Reference
Yes	17.77	(16.8–18.8)	1.56	(1.46–1.65)	< 0.01*	1.21	(1.14-1.29)	< 0.01*

^aAdjusted Relative risk: adjusted with age at delivery, income, urbanization, parity, acute coronary syndrome, chronic ischemic heart disease, stroke, diabetes mellitus, chronic hypertension and hyperthyroidism

^bAcute Coronary syndrome included myocardial infarction and unstable angina

*P < 0.05