Puza S, Roth N, Macones G A, Mennuti M T, Morgan M A
Department of Obstetrics and Gynecology, University of Pennsylvania Medical Center, Philadelphia, USA.
J Perinatol. 1998 Jan-Feb;18(1):9-12.
To determine whether the increase in frequency of cesarean section is associated with a decreased incidence of major birth trauma.
A retrospective cohort study was performed evaluating all neonatal cases of major birth trauma from January 1989 to December 1994. Major birth trauma was defined as peripheral plexus or nerve injuries, fractures, or lacerations. The data were grouped into two mutually exclusive periods (January 1989 to December 1990 vs January 1991 to December 1994) in which a significant difference in the cesarean section rate was known.
Of 17,957 deliveries during the period, 141 cases of birth trauma occurred. One hundred thirty-seven of the 141 medical records were available for review, and 116 were classified as having had major birth trauma and were included in the study. The overall incidence of major birth trauma was 6.5/1000 deliveries. During the two-year period (January 1989 to December 1990), 18.3% of deliveries were by cesarean section and the major birth trauma rate was 8.4/1000 deliveries. During the following 4 years, the cesarean section rate was 22.3% and the major birth trauma rate was 5.3/1000 deliveries. Significant differences in the birth trauma chi(2) = 6.12, p = 0.013) and cesarean section (chi(2) = 40.80, p < 0.001) rates were observed. Controlling for the mode of delivery lessened the association between time period and birth trauma incidence (chi(2)MH = 3.28, p = 0.07). A significant decrease in the occurrence of major birth trauma in neonates delivered by cesarean section in the later period was discovered (relative risk = 0.46, 95% confidence interval 0.22 to 0.97). This decrease appeared to be mediated by a decrease in total lacerations between the periods (chi(2) = 11.76, p < 0.001), because the rates of other types of major birth trauma did not differ in neonates delivered by cesarean section or the vaginal route.
With a 4% increase in rate of cesarean section at our institution, a significant decrease in the occurrence of major birth trauma was observed. This finding cannot be explained by a decreased risk of neonatal trauma in patients delivering vaginally, but rather by a decreased risk of neonatal trauma at cesarean section during the latter period.
确定剖宫产率的增加是否与严重分娩创伤发生率的降低相关。
进行了一项回顾性队列研究，评估1989年1月至1994年12月期间所有严重分娩创伤的新生儿病例。严重分娩创伤定义为周围神经丛或神经损伤、骨折或撕裂伤。数据被分为两个相互排斥的时期（1989年1月至1990年12月与1991年1月至1994年12月），已知这两个时期的剖宫产率存在显著差异。
在该时期的17957例分娩中，发生了141例分娩创伤。141份病历中的137份可供审查，其中116份被归类为患有严重分娩创伤并纳入研究。严重分娩创伤的总体发生率为6.5/1000例分娩。在两年期（1989年1月至1990年12月），18.3%的分娩为剖宫产，严重分娩创伤率为8.4/1000例分娩。在随后的4年中，剖宫产率为22.3%，严重分娩创伤率为5.3/1000例分娩。观察到分娩创伤（χ² = 6.12，p = 0.013）和剖宫产（χ² = 40.80，p < 0.001）率存在显著差异。控制分娩方式后，时期与分娩创伤发生率之间的关联减弱（χ²MH = 3.28，p = 0.07）。发现后期剖宫产分娩的新生儿中严重分娩创伤的发生率显著降低（相对风险 = 0.46，95%置信区间0.22至0.97）。这种降低似乎是由两个时期之间总撕裂伤的减少介导的（χ² = 11.76，p < 0.001），因为剖宫产或阴道分娩的新生儿中其他类型严重分娩创伤的发生率没有差异。
在我们机构剖宫产率增加4%的情况下，观察到严重分娩创伤的发生率显著降低。这一发现不能用阴道分娩患者新生儿创伤风险的降低来解释，而应归因于后期剖宫产时新生儿创伤风险的降低。
