巨大胎儿对产妇盆底功能的影响

Effects of macrosomia on pelvic floor function of puerperae

目的探讨巨大胎儿对产妇产后早期盆底功能障碍性疾病(PFD)发生的影响。方法选择2014年3至12月,在湖北医药学院附属襄阳市第一人民医院产科进行阴道分娩,并于产后6~8周复查盆底功能等检查的301例孕足月初产妇为研究对象。根据所分娩新生儿的体重,将产妇分为研究组(n=145,分娩巨大胎儿,新生儿出生体重≥4 000g)和对照组(n=156,分娩正常体重胎儿,3 000g≤新生儿出生体重<4 000g)。对2组产妇一般临床资料,盆底肌肌力、盆底肌疲劳度及阴道动态压力正常者所占比例,产后压力性尿失禁(SUI)及盆腔脏器脱垂(POP)发生情况,以及产妇会阴超声检查结果,采用成组t检验或χ~2检验进行统计学比较。本研究通过湖北医药学院附属襄阳市第一人民医院伦理委员会的伦理审查并获批准,取得产妇知情同意、签署知情同意书。结果 (1)2组产妇年龄、孕前人体质量指数、产程延长发生率、会阴侧切发生率及家庭月收入等一般临床资料比较,差异均无统计学意义(P>0.05)。(2)盆底Ⅰ类和Ⅱ类肌纤维肌力正常者所占比例,研究组分别为9.7%和11.0%,对照组分别为19.2%和21.2%;盆底Ⅰ类和Ⅱ类肌纤维疲劳度正常者所占比例,研究组分别为15.9%和11.7%,对照组分别为30.8%和26.3%;阴道动态压力正常者所占比例,研究组和对照组分别为31.0%和81.4%。研究组产妇上述指标所占比例均低于对照组,并且差异均有统计学意义(χ~2=5.521,P=0.019;χ~2=5.646,P=0.017;χ~2=9.265,P=0.002;χ~2=10.238,P=0.001;χ~2=77.873,P<0.001)。(3)研究组产妇产后SUI及阴道前、后壁脱垂发生率(9.0%、27.6%、25.5%),均高于对照组产妇(2.6%、11.5%、10.3%),并且差异均有统计学意义(χ~2=5.779,P=0.016;χ~2=12.441,P<0.001;χ~2=12.064,P=0.001)。(4)38例研究组产妇和40例对照组产妇的会阴超声检查结果显示,研究组产妇POP发生率,Valsalva动作时的膀胱颈下移距离和尿道转移角度,以及平静时、缩肛动作时及Valsalva动作时的肛提肌裂孔面积[68.4%,(28.4±5.8)mm,(46.2±16.3)°,(15.1±3.5)mm^2,(13.6±1.6)mm^2,(22.9±5.2)mm^2],均高于或大于对照组的40.0%,(6.4±4.4)mm,(19.3±13.2)°,(12.9±3.4)mm^2,(11.1±2.3)mm^2,(14.3±2.8)mm^2,并且差异均有统计学意义(χ~2=6.334,P=0.012;t=18.930,P<0.001;t=8.029,P<0.001;t=2.816,P=0.006;t=5.545,P<0.001;t=9.157,P<0.001)。结论巨大胎儿可使产妇产后盆底肌肌力和阴道动态压力下降,盆底肌疲劳度增加,从而导致产后SUI和POP。经三维超声检查,可早期发现产后轻度盆底功能障碍及肛提肌损伤。

Objective To investigate effects of macrosomia on the incidence of early pelvic floor dysfunction（PFD）in puerperae.Methods A total of 301 primiparae who had full-term pregnancy and vaginal delivery,and evaluated the pelvic floor function after 6-8 weeks postpartum from March to December 2014 in Affliated Hospital of Hubei University of Medicine,Xiangyang No.1 People′s Hospital,were chosen as research subjects.According to birth weight of newborns,they were divided into study group（n=145,macrosomia delivery,birth weight≥4 000 g）and control group（n=156,normal weight fetus delivery,3 000 g≤ birth weight4 000 g）.The general clinical data,the proportion of normal pelvic floor muscle strength,fatigue degree and vaginal dynamic pressure,incidence rates of postpartum stress urinary incontinence（SUI）and pelvic organ prolapse（POP）,and the results of maternal perineal ultrasonography were all statistically compared between two groups of puerperae by independent-samples t test or chi-square test.The study protocol was approved by the Ethics Committee of Affliated Hospital of Hubei University of Medicine,Xiangyang No.1 People′s Hospital,and informed consents were obtained and signed by participants.Results（1） There were no significant differences between two groups of puerperae in general clinical data such as maternal age,body mass index before pregnancy,incidence rates of prolonged labor and perineal episiotomy,family monthly income,etc.（P〈0.05）.（2）The proportions of normal pelvic floor typeⅠ and Ⅱ muscle fibers strength of puerperae were 9.7% and 11.0%in study group,and 19.2% and 21.2%in control group,respectively;The proportions of normal pelvic floor type Ⅰ and Ⅱ muscle fibers fatigue degrees of puerperae were 15.9% and 11.7% in study group,and 30.8% and 26.3% in control group,respectively;The proportions of normal vaginal dynamic pressure of puerperae were 31.0%in study group and 81.4%in control group,respectively.The above mentioned proportions of indexes of puerperae in study group were all lower than those in control group,and all the differences were statistically significant（χ~2=5.521,P=0.019;χ~2=5.646,P=0.017;χ~2=9.265,P=0.002;χ~2=10.238,P=0.001;χ~2=77.873,P〈0.001）.（3）The incidence rates of SUI,anterior and posterior vaginal walls prolapse of puerperae in study group（9.0%,27.6%,25.5%）were all higher than those in control group（2.6%,11.5%,10.3%）,and the differences were statistically significant（χ~2=5.779,P=0.016;χ~2=12.441,P〈0.001;χ~2=12.064,P=0.001）.（4）The results of perineal ultrasonography in 38 cases of puerperae in study group and 40 cases of puerperae in control group showed that incidence rates of POP,the distance of downward dislocation of bladder neck and urethral metastatic angle during Valsalva movement,and the levator ani muscle hole area during calm state,anal contraction and Valsalva movements in study group[68.4%,（28.4±5.8）mm,（46.2±16.3）°,（15.1±3.5）mm^2,（13.6±1.6）mm^2,（22.9±5.2）mm^2]were all higher,wider or larger than those in control group [40.0%,（6.4 ± 4.4） mm,（19.3 ± 13.2）°,（12.9 ± 3.4） mm^2,（11.1±2.3）mm^2,（14.3±2.8）mm^2],and the differences were statistically significant（χ~2=6.334,P=0.012;t=18.930,P〈0.001;t=8.029,P〈0.001;t=2.816,P=0.006;t=5.545,P〈0.001;t=9.157,P〈0.001）.Conclusions Macrosomia can reduce pelvic floor muscle strength and vaginal dynamic pressure of puerperae,increase muscle fatigue degree,which resulting in SUI and POP in postpartum.Mild PFD and injuries of levator ani muscle should be detected by postpartum three dimensional ultrasonography.