Besinger R E, Moniak C W, Paskiewicz L S, Fisher S G, Tomich P G
Department of Obstetrics and Gynecology, Loyola University-Chicago, Maywood, IL 60153, USA.
Am J Obstet Gynecol. 1995 Jun;172(6):1770-5; discussion 1775-8. doi: 10.1016/0002-9378(95)91410-2.
The null hypothesis is that tocolysis has no effect on pregnancy prolongation in the aggressive expectant management of symptomatic preterm placenta previa.
One hundred twelve preterm pregnancies with confirmed placenta previa and an initial episode of acute vaginal bleeding were selected for this retrospective analysis. Exclusion criteria included gestational age > or = 35 weeks, delivery within 24 hours of admission, prior treatment for bleeding or preterm labor, and contraindications to tocolytic use. Tocolysis was prescribed, at the discretion of the treating clinical staff, in selected pregnancies with significant uterine contractions after admission of the patient. The majority of treated patients (85%) received intravenous magnesium sulfate and/or oral or subcutaneous beta-sympathomimetics within 24 hours of admission. Most patients remained hospitalized until delivery under this aggressive expectant management protocol. Both treated and untreated control study groups were similar at inclusion with regard to parity, gestational age, contraction frequency, and degree of initial bleeding. Outcome variables for each treatment group were obtained from final chart review. Continuous and categoric variables were compared with Student t test or chi 2 analysis-Fisher's exact test, respectively.
The clinical use of tocolysis in symptomatic placenta previa was associated with a clinically significant delay of preterm delivery. Significant improvement in clinical parameters such as interval from admission to delivery (39.2 vs 26.9 days, p < 0.02) and birth weight (2520 vs 2124 gm, p < 0.03) was observed in the tocolysis group. There was no observed statistical difference between the two treatment groups with regard to incidence of recurrent bleeding, interval from admission to first recurrent bleeding, and need for transfusion. There was a trend for patients with multiple bleeding episodes to have been receiving tocolytic therapy (p < 0.10). A trend for requiring a postpartum transfusion was also noted in the tocolysis group (p < 0.09). Treated pregnancies receiving long-term maintenance tocolysis with oral or subcutaneous terbutaline exhibited a greater degree of pregnancy prolongation than those treated with short-term intravenous magnesium alone (43.7 vs 15.3 days, p < 0.02).
This retrospective analysis suggests that tocolytic intervention in cases of symptomatic preterm previa may be associated with clinically significant prolongation of pregnancy and increased birth weight. Tocolytic therapy in these cases does not appear to have an impact on frequency or severity of recurrent vaginal bleeding. Further prospective analysis may delineate the role of tocolysis in the aggressive expectant management of symptomatic placenta previa.
无效假设是在有症状的前置胎盘积极期待治疗中，宫缩抑制剂对延长孕周无效。
选取112例确诊前置胎盘且首次出现急性阴道出血的早产孕妇进行回顾性分析。排除标准包括孕周≥35周、入院后24小时内分娩、既往有出血或早产治疗史以及宫缩抑制剂使用禁忌证。由治疗临床人员酌情决定，对入院后出现明显子宫收缩的部分孕妇使用宫缩抑制剂。大多数接受治疗的患者（85%）在入院后24小时内接受了静脉硫酸镁和/或口服或皮下β-拟交感神经药治疗。在这种积极的期待治疗方案下，大多数患者一直住院至分娩。治疗组和未治疗的对照组在纳入时，在产次、孕周、宫缩频率和初始出血程度方面相似。每个治疗组的结局变量通过最终病历审查获得。连续变量和分类变量分别采用Student t检验或卡方分析（Fisher精确检验）进行比较。
有症状前置胎盘临床使用宫缩抑制剂与早产分娩的临床显著延迟相关。宫缩抑制剂组在诸如入院至分娩间隔（39.2天对26.9天，p<0.02）和出生体重（2520克对2124克，p<0.03）等临床参数方面有显著改善。两组在复发性出血发生率、入院至首次复发性出血间隔以及输血需求方面未观察到统计学差异。有多次出血发作的患者接受宫缩抑制剂治疗有一定趋势（p<0.10）。宫缩抑制剂组在产后输血需求方面也有一定趋势（p<0.09）。接受口服或皮下特布他林长期维持宫缩抑制剂治疗的孕妇孕周延长程度大于仅接受短期静脉硫酸镁治疗的孕妇（43.7天对15.3天，p<0.02）。
这项回顾性分析表明，对有症状的早产前置胎盘病例进行宫缩抑制剂干预可能与临床显著延长孕周和增加出生体重有关。这些病例中的宫缩抑制剂治疗似乎对复发性阴道出血的频率或严重程度没有影响。进一步的前瞻性分析可能会明确宫缩抑制剂在有症状前置胎盘积极期待治疗中的作用。
