Nelson Richard L, Furner Sylvia E, Westercamp Matthew, Farquhar Cindy
Department of General Surgery, Northern General Hospital, Herries Road, Sheffield, Yorkshire, UK, S5 7AU.
Cochrane Database Syst Rev. 2010 Feb 17;2010(2):CD006756. doi: 10.1002/14651858.CD006756.pub2.
Caesarean delivery (CD) is a common form of delivery of a baby, rising in frequency. One reason for its performance is to preserve maternal pelvic floor function, part of which is anal continence.
To assess the ability of CD in comparison to vaginal delivery (VD) to preserve anal continence in a systematic review
Search terms include: "Caesarean section, Cesarean delivery, vaginal delivery, incontinence and randomised". PubMed, EMBASE and the Cochrane Central Register of Controlled Trials (Central) were searched from their inception through July, 2009.
Both randomised and non-randomised studies that allowed comparisons of post partum anal continence (both fecal and flatus) in women who had had babies delivered by either CD or VD were included.
Mode of delivery, and when possible mode of all previous deliveries prior to the index pregnancy were extracted, as well as assessment of continence post partum of both faeces and flatus. In Non-RCTs, available adjusted odds ratios were the primary end point sought. Incontinence of flatus is reported as a separate outcome. Summary odds ratios are not presented as no study was analysed as a randomised controlled trial. Numbers needed to treat (NNT) are presented, that is, the number of CDs needed to be performed to prevent a single case of fecal or flatus incontinence, for each individual study. Quality criteria were developed, selecting studies that allowed maternal age adjustment, studies that allowed a sufficient time after the birth of the baby for continence assessment and studies in which mode of delivery of prior pregnancies was known. Subgroup analyses were done selecting studies meeting all quality criteria and in comparisons of elective versus emergency CD, elective CD versus VD and nulliparous women versus those delivered by VD or CD, in each case again, not calculating a summary risk statistic.
Twentyone reports have been found eligible for inclusion in the review, encompassing 31,698 women having had 6,028 CDs and 25,170 VDs as the index event prior to anal continence assessment . Only one report randomised women (with breech presentation) to CD or VD, but because of extensive crossing over, 52.1%, after randomisation, it was analysed along with the other 20 studies as treated, i.e. as a non-randomised trial. Only one of these reports demonstrated a significant benefit of CD in the preservation of anal continence, a report in which incontinence incidence was extremely high, 39% in CD and 48% in VD, questioning, relative to other reports, the timing and nature of continence assessment. The greater the quality of the report, the closer its Odds ratio approached 1.0. There was no difference in continence preservation in women have emergency versus elective CD.
AUTHORS' CONCLUSIONS: Without demonstrable benefit, preservation of anal continence should not be used as a criterion for choosing elective primary CD. The strength of this conclusion would be greatly strengthened if there were studies that randomised women with average risk pregnancies to CD versus VD.
剖宫产是一种常见的分娩方式，其发生率呈上升趋势。进行剖宫产的一个原因是为了保护产妇的盆底功能，其中部分功能是肛门节制。
通过系统评价评估剖宫产与阴道分娩相比在保护肛门节制方面的能力。
检索词包括：“剖宫产、剖腹产、阴道分娩、失禁和随机化”。对PubMed、EMBASE和Cochrane对照试验中央注册库（CENTRAL）从建库至2009年7月进行检索。
纳入了允许比较剖宫产或阴道分娩的产妇产后肛门节制（包括粪便和气体）情况的随机和非随机研究。
提取分娩方式，以及在本次索引妊娠之前所有既往分娩的方式（若可能），同时提取产后粪便和气体节制情况的评估。在非随机对照试验中，可用的调整优势比是主要的研究终点。气体失禁作为一个单独的结果进行报告。由于没有研究作为随机对照试验进行分析，因此未给出汇总优势比。给出了需要治疗的人数（NNT），即对于每项单独研究，为预防一例粪便或气体失禁需要进行的剖宫产数量。制定了质量标准，选择允许调整产妇年龄的研究、在婴儿出生后有足够时间进行节制评估的研究以及已知既往妊娠分娩方式的研究。进行亚组分析时，选择符合所有质量标准的研究，并比较择期剖宫产与急诊剖宫产、择期剖宫产与阴道分娩以及未产妇与经阴道分娩或剖宫产的产妇，同样在每种情况下均未计算汇总风险统计量。
已发现21篇报告符合纳入本评价的标准，涵盖31698名妇女，其中6028例剖宫产和25170例阴道分娩作为肛门节制评估之前的索引事件。只有一篇报告将妇女（臀位）随机分为剖宫产或阴道分娩组，但由于随机分组后有大量交叉，随机分组后52.1%的妇女被纳入，该报告与其他20项研究一起按实际治疗情况进行分析，即作为非随机试验。这些报告中只有一篇显示剖宫产在保护肛门节制方面有显著益处，该报告中失禁发生率极高，剖宫产组为39%，阴道分娩组为48%，与其他报告相比让人质疑节制评估的时间和性质是否合理。报告质量越高，其优势比越接近1.0。急诊剖宫产与择期剖宫产的产妇在节制保护方面没有差异。
在没有明确益处的情况下，不应将保护肛门节制作为选择择期初次剖宫产的标准。如果有将平均风险妊娠的妇女随机分为剖宫产组和阴道分娩组的研究，这一结论的力度将大大加强。
