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Labetalol Doesn't Affect Nonstress Tests


 

From the annual meeting of the American College of Obstetricians and Gynecologists

Major Finding: The rate of reactive nonstress tests in pregnant women with chronic hypertension was not significantly different in 76 patients treated with labetalol (84%), compared with 36 treated with methyldopa (81%).

Data Source: Retrospective study of all pregnant women treated for chronic hypertension at one institution from January 2003 to September 2007.

Disclosures: None was reported.

SAN FRANCISCO — Results of nonstress tests in 112 pregnant women being treated for chronic hypertension from January 2003 to September 2007 did not differ significantly in patients on labetalol, compared with those on methyldopa, results of a retrospective study found.

“Attending physicians should feel comfortable using labetalol or methyldopa for pregnant patients with hypertension. Those medications have no effect on the baby,” Dr. Ramata Niang said in an interview at her prize-winning poster presentation at the meeting.

She and her associates had hypothesized that treatment with labetalol would increase the rate of nonreactive nonstress tests, but found no evidence of that.

Nonstress tests were reactive in 84% of 76 patients on labetalol and in 81% of 36 patients on methyldopa, a difference that was not statistically significant, reported Dr. Niang, an ob.gyn. at the University of Illinois at Chicago.

Among U.S. pregnant women, 10% have hypertension, which has been associated with an increased risk for perinatal morbidity and mortality. Traditionally, methyldopa has been used to treat hypertension during pregnancy, but in recent years more physicians have begun using beta-blockers or other medications. Labetalol is both a selective alpha-blocker and a nonselective beta-blocker that decreases systemic vascular resistance without changing maternal cardiac output.

Investigators used the average of nonstress test results for each patient to categorize results as reactive or nonreactive. The study started with charts on 188 women treated for hypertension during pregnancy and excluded women with multiple-gestation pregnancies, other antihypertensive treatment, or incomplete prenatal testing charts, to focus on the remaining 112 patients.

There were no significant differences between the two treatment groups in maternal age (29 years for women on labetalol and 31 years for those on methyldopa), gestational age at delivery (37 and 38 weeks), birth weight (2,823 g and 3,048 g), or the rate of preeclampsia (less than 1% in both groups).

Black patients made up 74% of the labetalol group and 53% of the methyldopa group, while white patients made up 12% and 23% of the two groups, respectively; Hispanics made up 6% of the labetalol group and 15% of the methyldopa group, with other races/ethnicities accounting for the remainder.

'Attending physicians should feel comfortable using labetalol or methyldopa.'

Source DR. NIANG

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