Use of antihypertensive medications in pregnancy and the risk of adverse perinatal outcomes: McMaster Outcome Study of Hypertension In Pregnancy 2 (MOS HIP 2)

Table 5 Rate and adjusted odds ratios (OR) for the primary composite outcome, small for gestational age birthweight (SGA) and preterm birth among the offspring of women with chronic hypertension, according to type of antihypertensive therapy received during pregnancy

					Preterm birth
	Primary composite outcome^*		SGA		Before 32 weeks		Before 37 weeks
Type of antihypertensive therapy	Rate (%)	Adjusted OR (95% CI)^#	Rate (%)	Adjusted OR (95% CI)	Rate (%)	Adjusted OR (95% CI)	Rate (%)	Adjusted OR (95% CI)
None	12.9	1.0	7.3	1.0	2.0	1.0	12.2	1.0
β-blocker	26.1	1.4 (0.6–3.4)	18.8	2.3 (1.1–4.5)	10.4	4.0 (1.3–12.4)	39.6	4.0 (2.3–6.9)
Non-β-blocker	48.8	4.9 (1.7–14.2)	14.5	1.3 (0.5–3.4)	12.0	2.0 (0.5–7.4)	48.2	4.2 (2.2–8.1)
Both β-blocker and non-β-blocker	53.7	2.9 (1.1–7.7)	26.6	2.9 (1.3–6.3)	26.6	5.3 (1.7–16.3)	80.7	18.9 (9.6–37.3)

^*Defined as a composite of either hyaline membrane disease, necrotizing enterocolitis, periventricular hemorrhage, assisted ventilation > 1 day, or perinatal death after 20 weeks gestation and up to 30 days after birth. ^#All odds ratios were adjusted for maternal age, parity, pre-pregnancy weight, history of delivery before 34 weeks, history of hypertension in a previous pregnancy, cigarette smoking, pre-pregnancy diabetes mellitus, pre-pregnancy renal dysfunction, development of proteinuria, use of prednisone, receipt of betamethasone for fetal lung maturity (which is excluded for the analysis of SGA and preterm delivery), and the presence of ≥ 2+ proteinuria or 300 mg of urinary protein per 24-hour specimen.

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