Mercer Brian M, Merlino Amy A
From the Department of Obstetrics & Gynecology, MetroHealth Medical Center, Cleveland, Ohio.
Obstet Gynecol. 2009 Sep;114(3):650-668. doi: 10.1097/AOG.0b013e3181b48336.
Approximately half of the more than 500,000 preterm births each year result from preterm labor. Tocolytic therapy continues to be the focus of treatment of these women. Although a variety of tocolytics are used in clinical practice, magnesium sulfate remains one of the most commonly used agents. Magnesium sulfate has also been the focus of recent research for its potential neuroprotective effects for neonates born preterm. Evaluation of 19 randomized clinical trials reveals that magnesium sulfate tocolysis does not reduce the frequencies of delivery within 48 hours, 7 days, or early/late preterm birth, and is not associated with improvements in newborn morbidities or mortality. No other tocolytic class resulted in improved newborn outcomes when compared with magnesium sulfate tocolysis. We conclude that it is appropriate to withhold tocolysis with magnesium sulfate or other agents from women presenting in preterm labor as newborn benefit has not been demonstrated with such treatment. If initiated to achieve time for antenatal corticosteroid administration, or for other acute reasons, treatment can be discontinued once these goals have been achieved or if labor subsides before then. Because brief pregnancy prolongation is unlikely to improve newborn outcomes after corticosteroid administration has been completed, it is appropriate to withhold magnesium sulfate tocolysis from women with recurrent preterm labor thereafter. If magnesium sulfate is given for neuroprotection, a protocol from one of the three major trials that have demonstrated benefits should be used.
每年超过50万例早产中，约有一半是由早产临产引起的。宫缩抑制剂疗法仍然是这些孕妇治疗的重点。尽管临床实践中使用了多种宫缩抑制剂，但硫酸镁仍然是最常用的药物之一。硫酸镁因其对早产新生儿潜在的神经保护作用，也一直是近期研究的重点。对19项随机临床试验的评估显示，硫酸镁宫缩抑制并不能降低48小时内、7天内或早产/晚期早产的分娩频率，也与新生儿发病率或死亡率的改善无关。与硫酸镁宫缩抑制相比，没有其他类别的宫缩抑制剂能改善新生儿结局。我们得出结论，对于早产临产的女性，不给予硫酸镁或其他药物进行宫缩抑制是合适的，因为这种治疗尚未证明对新生儿有益。如果开始治疗是为了争取时间给予产前糖皮质激素，或出于其他急性原因，一旦这些目标实现或在此之前宫缩缓解，治疗即可停止。由于在完成糖皮质激素给药后，短暂延长孕周不太可能改善新生儿结局，因此对于此后复发性早产临产的女性，不给予硫酸镁宫缩抑制是合适的。如果给予硫酸镁用于神经保护，应采用三项已证明有益的主要试验之一的方案。
