Newswise — Routine recommendation of bed rest for pregnant women with hypertension is not strongly supported by the limited available research, according to a new systematic review of clinical studies.
In four studies comprising 449 women, bed rest was not shown to reduce the risk of infant death or low birth weight, although two of the studies showed some benefit for women with severe hypertension.
"Despite the fact that rest is frequently prescribed by clinicians to pregnant women with hypertension, few well-designed trials have evaluated the effects of bed rest for hypertension in pregnancy," says author Shireen Meher, M.D., of the University of Liverpool. "At present, there is insufficient evidence to guide clinical practice on the effects of recommending bed rest to women with hypertension during pregnancy."
The review appears in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.
Two of the studies involved 145 hospitalized women diagnosed with pre-eclampsia — hypertension in which the urine contains an abnormal amount of protein. Some women also had chronic hypertension. The studies compared strict bed rest with partial bed rest. The researchers found no significant differences in severe maternal hypertension or in untoward birth outcomes between groups.
The other two studies involved 304 women with either pregnancy-induced or chronic hypertension but without protein in the urine. The studies showed a reduced risk of severe hypertension and a borderline reduction of risk of preterm delivery for women accepting some rest compared to those undertaking normal activities. Other outcomes were comparable for both groups.
Beyond the obvious inconvenience, "Bed rest in hospital or at home has financial implications for women and their families, and for healthcare services," the authors say. Their study did not report on cost, however.
Bed rest may have physical costs as well, the authors suggest: "Prolonged bed rest may be associated with complications such as thrombosis, muscle atrophy or bone demineralization."
The reviewers note that a majority of women in the bed-rest group said that they would not choose bed rest in future pregnancies.
Hypertension, or high blood pressure, is a common medical complication of pregnancy, affecting an estimated 6 percent to 8 percent of all pregnancies, according to the American College of Obstetrics and Gynecology.
Sharon Phelan M.D., a professor of obstetrics and gynecology at the University of New Mexico, and a spokesperson for ACOG, says, "Much of the push for bed rest came in the period from 1950 to 1960 when hypertensive disease in pregnancy was a cause of significant mortality and morbidity for mother and infant. At that time there was neither good medication for intervention nor methods for monitoring the fetus for well-being or compromise."
Now, Phelan says, "there are better medications for hypertension in pregnancy, more effective methods to monitor for fetal compromise and the implications of delivery an infant 4 to 6 weeks early are less devastating than in the past."
James N. Martin, Jr., M.D., chief of obstetrics for the Wiser Hospital for Women and Infants at the University of Mississippi Medical Center in Jackson, says, "What is really needed to answer the question about the role of bed rest, if any, in this complex gestational equation is to have sufficient patients randomized at varying gestational ages in association with each of the principal categories of acute pregnancy hypertensive disease"¦. This would be a formidable task and, some would argue, an impossible task."
Meher S., et al. Bed rest with or without hospitalization for hypertension during pregnancy (Review). The Cochrane Library 2005, Issue 4.
The Cochrane Collaboration is an international nonprofit, independent organization that produces and disseminates systematic reviews of health care interventions and promotes the search for evidence in the form of clinical trials and other studies of interventions. Visit http://www.cochrane.org for more information.