Risk Factors Analysis Of Uterine Rupture In Scarred Uterus In The Third Trimester Of Pregnancy

Objective:Uterine rupture refers to uterine laceration during pregnancy or delivery,which is a serious obstetrical complication that threatens the life and safety of mother and child.In recent years,with the increase of scar uterine pregnancy caused by uterine surgery,scar uterine pregnancy has become one of the important causes of uterine rupture.This study retrospectively analyzed the clinical data of patients with complete or incomplete rupture of scarred uterus in the third trimester of pregnancy in Shenyang Women's and Children'Hospital from October 1,2016 to October 1,2019.To explore the risk factors of uterine rupture in the third trimester of scar uterus,in order to provide reference for clinical early diagnosis and treatment of this obstetrical emergency in order to avoid adverse maternal and infant outcomes.Methods:During the three years from October 1,2016 to October 1,2019,the total number of deliveries in Shenyang Women's and Children's Hospital was 44648 cases.A total of5173 patients with scar uterine pregnancy and delivery were enrolled in this study,4768patients with complete and incomplete uterine rupture were selected as the study group according to certain inclusion criteria and exclusion criteria.276 patients with complete and incomplete uterine rupture were selected as the study group,and 4492 patients without uterine rupture in the same period were randomly selected as the control group.The general situation of the patients was collected,and the general conditions of 556patients in the study group and the control group were analyzed retrospectively.The age,gestational week,routine pregnancy examination,residence,hospital level of the last uterus operation,neonatal weight,the number of previous uterine operations,the history of early abortion,the interval between this pregnancy and the previous uterine operation,the concentration of hemoglobin in the third trimester of pregnancy,the body mass index before pregnancy and the degree of weight gain were compared between the two groups.The statistical software SPSS26.0 was used to analyze the clinical data of the patients in the study group and the control group.c~2-test was used to compare the counting data.The significant variables in univariate analysis were analyzed by multivariable logistic regression,and the relative risk(OR)and 95%confidence interval(95%CI),P<0.05thought to be statistically significant)were calculated to screen out the risk factors of scar uterine rupture in the third trimester of pregnancy.At the same time,the clinical data of 276 patients with uterine rupture were reviewed,including previous operations,clinical manifestations,diagnosis and treatment of this pregnancy,and the clinical characteristics of patients with uterine rupture were analyzed in detail.Results:Univariate analysis showed that uterine rupture of scar uterus in late pregnancy was correlated with maternal age,routine pregnancy examination,times of uterine operation,interval between pregnancy and uterine operation and hemoglobin concentration in the third trimester,but not with gestational week,residence,hospital grade of last operation,neonatal weight,history of early abortion,BMI before pregnancy and the degree of weight gain during pregnancy.The results of multivariate logistic regression analysis showed that non-routine pregnancy examination,history of multiple uterine operations,advanced age and pregnancy less than 2 years from the previous uterine operation were the independent risk factors for uterine rupture of scar uterus in the third trimester of pregnancy,among which the risk of not having routine pregnancy examination was the highest(OR4.967,95%CI:1.38-17.874),followed by the interval between pregnancy and the previous uterine operation less than 2 years(OR2.657,95%:1.463-4.824).History of multiple uterine operations(OR2.495,95%CI:1.214-5.127),advanced age(OR1.832,95%CI:1.263-2.659).Of the 276 patients in this study group,3 had complete uterine rupture.Among them,two cases of uterine rupture occurred 2 years after laparoscopic myomectomy(Laparoscopic myomectomy,LM),one case was hospitalized with vaginal bleeding with persistent lower abdominal pain and shock at the33+5weeks of pregnancy,and the fetus survived by emergency cesarean section.During the operation,a rupture on the left side of the posterior wall of the uterus was found to be about 10 cm long,and the rupture was repaired.In another case,the fetal movement decreased at first,then the epigastric pain was not seen in time,and the abdominal pain worsened and the whole abdomen was admitted to the hospital for emergency operation.During the operation,a complete breach of about 12cm in length from the lower part of the anterior wall of the uterus to the posterior wall of the uterus was seen,and the fetal cell was located in the abdominal cavity and the fetus was dead.After the dead fetus was removed,the repair of uterine rupture was performed.The two patients were rescued by blood transfusion during operation,and the prognosis of the parturient was good.The other case was admitted to hospital for irregular abdominal pain at 38 weeks of pregnancy,it was 7 years between pregnancy and prior cesarean section.Emergency cesarean section was performed with body examination and lower uterine segment tenderness,during the operation,there was a 1cm tear on the left side of the lower segment of the uterus and amniotic sac was seen.A live baby was delivered,and there were no maternal and fetal complications.Most of the patients with incomplete uterine rupture had no specific symptoms and were diagnosed because of the thin myometrium and only one serosa in the lower segment of the uterus during cesarean section,and there were no maternal and fetal complications.Conclusion:1.Unroutine pregnancy examination,history of multiple uterine operations,advanced age and the interval between pregnancy and the previous uterine operation less than 2 years are the independent risk factors of scar uterine rupture in the third trimester of pregnancy.For patients with scar uterus with the above risks,monitoring should be strengthened in the third trimester to guard against uterine rupture.2.Pregnant women with multiple history of uterine surgery have an increased risk of uterine rupture in the third trimester of pregnancy,so women of childbearing age who are required to give birth should be very cautious in performing uterine surgery before pregnancy.3.Most of the clinical manifestations of scar uterine rupture are atypical,especially for pregnant women after myomectomy,we should pay attention to the relevant non-specific symptoms and be vigilant to avoid maternal and infant damage caused by uterine rupture not found in time.