Schneider Henning
Universitätsfrauenklinik, Inselspital Bern, Bern, Schweiz.
Gynakol Geburtshilfliche Rundsch. 2004 Jan;44(1):10-18. doi: 10.1159/000074312.
In view of the general improvement in survival of very early preterm newborns the contribution of the obstetrical management to this development has been studied.
A comprehensive literature search was performed concentrating on prospective randomised clinical trials, meta-analyses and review articles dealing with different aspects of the obstetrical management of very early preterm deliveries which were published during the last 10 years.
The benefit of antepartal administration of glucocorticoids to the mother for stimulation of pulmonary maturity of the fetus and the overall clinical condition of the preterm newborn at birth has been proven by several prospective randomised studies. In contrast, there is only indirect evidence for the benefit of an early transfer of these pregnancies to a perinatal centre. The benefit of a short-term prolongation of pregnancy by the administration of tocolytics is evident in the context of glucocorticoid administration for pulmonary maturity. There is no clear evidence for the benefit of long-term tocolytic treatment of preterm labour. Various prospective randomised trials comparing delivery by primary or elective caesarean section with vaginal birth combined with selective section as indicated by a deterioration of the condition of the fetus or the mother during the first or second stage of labour have clearly shown increased maternal morbidity in the elective caesarean section group. The expected advantage for the condition of the newborn could not be shown. In a meta-analysis of 6 such trials, the problem of recruiting participants was stressed. All 6 trials had to be terminated before the calculated number of study participants had been recruited.
For planned early preterm delivery a transfer of the mother into perinatal centre is recommended for pregnancies beyond 22 0/7 weeks. Starting at 24 0/7 weeks, glucocorticoids should be administered. Between 24 0/7 and 24 6/7 weeks, survival chances remain clearly at less than 50%, and up to 50% of those surviving develop moderate to severe handicaps. Obstetrical management, in particular a decision for caesarean section due to fetal indication, must be individualised taking into account the wishes of the parents. Beyond 25 0/7 weeks, newborn survival should be given priority, and although clear evidence for the optimal mode of delivery is missing in cases of spontaneous labour leading to rapid dilatation of the cervix, with a normal singleton cephalic fetus, a vaginal delivery may be attempted. If under close supervision of labour there are signs of fetal or maternal deterioration, a caesarean section should be performed without delay. With breech presentation as well as twins or multiple fetuses there is a general trend towards primary caesarean section. In the absence of spontaneous labour and with an unripe cervix, elective caesarean section is considered as the method of choice for the delivery of the early preterm fetus.
鉴于极早早产儿存活率普遍提高，研究了产科管理对这一进展的贡献。
进行了全面的文献检索，重点关注过去10年发表的关于极早早产分娩产科管理不同方面的前瞻性随机临床试验、荟萃分析和综述文章。
多项前瞻性随机研究已证实，产前给母亲使用糖皮质激素对刺激胎儿肺成熟及早产新生儿出生时的整体临床状况有益。相比之下，这些妊娠早期转诊至围产期中心有益的证据仅为间接证据。在使用糖皮质激素促进肺成熟的背景下，使用宫缩抑制剂短期延长孕周的益处是明显的。没有明确证据表明早产长期使用宫缩抑制剂治疗有益。各种前瞻性随机试验比较了初次剖宫产或选择性剖宫产与阴道分娩加选择性剖宫产（根据第一产程或第二产程中胎儿或母亲状况恶化情况而定），结果清楚地表明选择性剖宫产组产妇发病率增加。未显示对新生儿状况有预期优势。在对6项此类试验的荟萃分析中，强调了招募参与者的问题。所有6项试验在招募到计算出的研究参与者数量之前就不得不终止。
对于计划中的极早早产分娩，建议将孕周超过22⁰/₇周的孕妇转诊至围产期中心。从24⁰/₇周开始，应给予糖皮质激素。在24⁰/₇至24⁶/₇周之间，存活机会明显仍低于50%，且存活者中高达50%会出现中度至重度残疾。产科管理，特别是因胎儿指征而决定剖宫产时，必须考虑父母的意愿进行个体化决策。超过25⁰/₇周，应优先考虑新生儿存活，尽管在自然分娩导致宫颈迅速扩张、单胎头位正常的情况下，缺乏关于最佳分娩方式的明确证据，但可尝试阴道分娩。如果在密切监测产程过程中有胎儿或母亲恶化的迹象，应立即进行剖宫产。臀位以及双胎或多胎妊娠时，一般倾向于初次剖宫产。在没有自然分娩且宫颈未成熟的情况下，选择性剖宫产被认为是极早早产儿分娩的首选方法。
