On Preterm Labor Drugs: Magnesium Sulfate vs. Nifedipine

Filed in archive Studies , Treatment on July 3, 2007

The commonly used preterm labor drug -magnesium sulfate - has been compared by researchers at Lucile Packard Children's Hospital and Stanford University School of Medicine to the common alternative treatment -- nifedipine.

[Preterm labor is defined as labor before 37 weeks' gestation. Although it's not always possible to prevent premature birth, physicians strive to delay delivery for at least 48 hours. The extra time allows a doctor to arrange to transfer the woman to a medical facility experienced in treating premature infants and helps maximize the effectiveness of steroids used to help the fetus to prepare for the harsh outside world.]

While the two drugs have similar effectiveness in arresting preterm labor, magnesium sulfate has been found to have more side effects that include vomiting, lethargy and blurry vision. Also, the findings suggest that newborns whose mothers had received magnesium sulfate were more likely to be admitted to the neonatal intensive care unit (ICU) than those whose mothers had received nifedipine.

Treatment with nifedipine usually makes women generally feeling better, according to the said study.

Magnesium sulfate, nifedipine and other preterm labor treatments, called tocolytics, are thought to work by relaxing overactive uterine muscles and halting ongoing cervical changes that may lead to delivery. But it's not been clear if one is better than the others. Force of habit has dictated the use of magnesium sulfate by many physicians in the absence of a compelling reason to choose an alternative.

The abovementioned findings came from the largest multicenter trial that randomized the use of the preterm labor drugs to compare outcome which is published in the July issue of Obstetrics & Gynecology.

Are these findings enough to make physicians choose nifedipine over magnesium sulfate in treating preterm labor? Or should a "higher up command" come from somewhere before they do?

Find more details from the full report.