| October 2012 · Vol. 24, No. 10 EXAMINING THE EVIDENCE
Does maternal exposure to
magnesium sulfate affect
fetal heart-rate patterns?Yes. Maternal exposure is associated with a lower fetal heart-rate baseline (within the accepted normal range), decreased variability, and fewer prolonged decelerations—but there is no evidence of adverse effects on neonatal outcomes, according to this 4-year retrospective cohort study.Duffy CR, Odibo AO, Roehl KA, Macones GA, Cahill AG. Effect of magnesium sulfate on fetal heart rate patterns in the second stage of labor. Obstet Gynecol. 2012;119(6):1129–1136. EXPERT COMMENTARY
John M. Thorp, Jr., MDHugh McAllister Distinguished Professor of Obstetrics and Gynecology at the University of North Carolina at Chapel Hill.
In contemporary obstetrics, electronic fetal monitoring (EFM) is used almost universally, and magnesium sulfate often is administered for seizure prophylaxis, tocolysis, or preterm neuroprotection. Given that magnesium crosses the placenta and is known to have both neurologic and cardiac effects and toxicities, it has been speculated that magnesium sulfate may change various characteristics of the fetal heart rate (FHR). Previous studies in small animals have failed to answer this common clinical question. CLICK HERE to read more |
