孕前不同体重指数对阴道分娩的影响

目的探索孕前不同体重指数对阴道分娩的影响。方法2008年1月至5月在我院住院并进行阴道试产的初产妇975例．按照孕前体重指数分为低体重组（BMI〈18．5）93例、正常体重组（18．5≤BMI〈23）604例、超重组（23≤BMI〈25）176例、肥胖组（BMI≥25）102例，观察孕前BMI与妊娠结局的关系。结果（1）孕前肥胖组的妇女的第一产程时限、第二产程时限明显长于其它组的妇女，差异有显著性（P〈0．05），第三产程时限在不同孕前BMI组间比较没有显著差异；（2）随着孕前BMI的增长，孕妇的剖宫产率逐渐增加．各组间剖宫产率比较有显著性差异（P〈O．05），其中肥胖组妇女的剖宫产率为33％。低体重组、正常体重组、超重组和肥胖组妇女的阴道助产率比较没有统计学差异。各组妇女的镇痛分娩比率有逐渐增加的趋势，其中肥胖组妇女的分娩镇痛率显著高于其它BMI组的妇女，差别有统计学意义（P〈0．05）；（3）低体重组、正常体重组、超重组和肥胖组间妇女分娩巨大儿的比率有统计学差异（P〈0．05），随着孕前BMI的增加，妇女分娩巨大儿的比率也增加，其中以肥胖组妇女分娩巨大儿的比例最高为17．6％。各组妇女发生肩难产的比例没有统计学差异。各组妇女分娩的新生儿转入新生儿监护的比例没有统计学差异，其中以正常体重组妇女分娩的新生儿NICU转入率最低，为27％，而以肥胖组妇女分娩的新生儿NICU转入率最高，为35％。结论孕前肥胖导致第一产程、第二产程延长．同时会增加剖宫产率、镇痛分娩率、分娩巨大儿的比例以及新生儿转监护率。

Influence of Prepregnancy Body Mass Index on Vaginal Delivery

Objective To explore the influence ofprepregnancy body mass index （BMI）on vaginal delivery. Methods We studied 975 nulliparous women who delivered between Jan 2008 and May 2008.Women were divided into four groups according to their prepregancy BMI： underweight group （n=93）; normal weight group （n=604）; overweight group （n=176）and obese group （n=102）, we observed the relationship between the prepregnancy BMI with pregnant outcomes. Results （1） the mean durations of the first stage of labor and the second stage of labor of the women in the obese group are longer than these of the women in other groups ,there is statistically significant different（P 〈0.05）. There is no statistically significant difference for the mean duration of the third stage of labor within the four groups. （2） the cesarean section rate increases with the increasing of the prepregnancy BMI, there is statistically significant different within the four groups（P 〈0.05）, with the highest cesarean section rate in the obese group（33%）. There is no statistically significant difference for the rate of assisted vaginal delivery within the four groups. There is a increasing tendency for the labor analgesia rote within the four groups, with the highest labor analgesia rate in the obese group, there is statistically significant different （P 〈0.05）. （3） There is statistically significant difference for the incidence rate of macrosomia within the four groups, with the highest in the obese group（17.6%）, there is no statistically significant difference for the rate of admission to the neonatal intensive care unit（NICU） within the four groups, with the lowest rate in the normal weight group （27%） and the highest rate in the obese group（35%）. Conclusion Prepregancy obesity results in the prolonged first stage of labor and the second stage of labor, also increases the rate of cesarean section, labor analgesia, macrosomia and admission to the NICU.