Dr. Barbieri responds: Until more data come in, avoid magnesium sulfate
I appreciate the perspectives provided by Dr. Toofanian and Dr. Klobutcher, as well as by Dr. Daniels and colleagues. As experienced clinicians, they all clearly recognize how difficult and frustrating it is to treat the multifactorial causes of prematurity, including the contribution of complex environmental factors such as psychosocial stress in the mother.
I agree with Dr. Toofanian that multimodal treatment of preterm labor might delay birth, but that great care must be taken to avoid adverse effects, such as maternal pulmonary edema.
Dr. Daniels and associates are correct that we need additional studies comparing magnesium sulfate to a placebo for the treatment of preterm labor. Until additional data indicate the effectiveness of magnesium, it is my “subjective” opinion that patients in preterm labor are best served by treatment with nifedipine, a β-agonist, or indomethacin. A continuing concern is that magnesium sulfate treatment of preterm labor, especially at dosages greater than 2 g/h, may be associated with adverse newborn outcomes.