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

• Main Authors: Vermeulen Marian J, Ray Joel G, Burrows Elizabeth A, Burrows Robert F
• Format: Article
• Language: English
• Published: BMC 2001-11-01
• Series: BMC Pregnancy and Childbirth
• Online Access: http://www.biomedcentral.com/1471-2393/1/6

<p>Abstract</p> <p>Background</p> <p>Uncertainty remains about the potential harmful effects of antihypertensive therapy on the developing fetus, especially for beta-blockers (βb).</p> <p>Methods</p> <p>We prospectively enrolled all singleton women with a blood pressure ≥ 140/90 mm Hg during pregnancy. The main analysis included 1948 women with all forms of hypertension and compared the use of βb drugs, non-βb drugs or a combination of both, to no treatment. The primary study outcome was a composite of the diseases of prematurity, need for assisted ventilation for greater than 1 day, or perinatal death. A sub-group analysis evaluated the four treatment options among 583 singleton women with chronic hypertension before 20 weeks gestation.</p> <p>Results</p> <p>In the main analysis, no association was observed between βb use and the primary composite outcome [adjusted odds ratio (OR) 1.4, 95% CI 0.9–2.2], while an association was seen with non-βb therapy (OR 5.0, 95% CI 2.6–9.6) and combination therapy (OR 2.9, 95% CI 1.8–4.7). In the sub-group of 583 women with hypertension before 20 weeks, use of a non-βb drug (OR 4.9, 95% CI 1.7–14.2) or combination therapy (OR 2.9. 95% CI 1.1–7.7) was significantly associated with the primary composite outcome, while βb monotherapy was not (OR 1.4, 95% CI 0.6–3.4).</p> <p>Conclusions</p> <p>Maternal use of antihypertensive medications other than βbs was associated with both major perinatal morbidity and mortality, while βb monotherapy was not. The combined use of βb and non-βb medications demonstrated the strongest association. Before definitive conclusions can be drawn, a large multicentre randomized controlled trial is needed to address the issues of both maternal efficacy and fetal safety with the use of one or more antihypertensive agents in pregnancy.</p>