The Study On Delivery Ways Of Premature Birth At ≤34 Gestational Weeks

Premature birth is an important, complicated and frequent pregnancy complication in perinatology. The pregnant women who labor at 28 to 37 gestational weeks (196d to 258d) are considered as premature delivery. And the infants born during this time is called as preterm infants, whose birth weights are often between 1000 to 2499g. They usually display the developmental immaturity in various organs, low viability, and are accompanied with more complication, which are faced with the second risk for the perinatal death (congenital malformation, the first). Prenatal health examination is the main means for pregnant woman. Combining with the application of high resolution B ultrasound and modern fetal monitor, it make more pregnant women having pregnancy complication have the chance to be found earlier as possible, but these women often can't be pregnant at term since their pathogenetic condition become serious. When premature delivery is unavoidable, the problem concerning about how to improve the life quality, decrease the death rate and disability rate of preterm infants with proper delivery ways is a great question for perinatology study. Bulk of evidences inside and outside the country indicated the preterm infant born at over 35 gestational weeks have a good prognosis, and there was no significant difference in their survival rate and complication when born by ways of vaginal delivery and uterine-incision delivery. Few systematic papers on delivery ways of preterm birth at≤34 gestational weeks, which was caused by various high risk factors, have been reported in domestic and overseas. At the background of low quality of perinatology inside the country, those preterm infants meet more risks of death and complications, due to less gestational weeks and birth weight. In addition to the more expanse for the therapy of preterm infant, the incorrect delivery ways selected at≤34 gestational weeks may do a great harm to the pregnant women and their family, which may further seriously affect the living quality of preterm infants at various aspects. The present study aims to investigate the proper selection of delivery methods and time of premature birth at≤34 gestational weeks, by studying the far and near complications of preterm infants born at≤34 gestational weeks with different delivery ways.The first part: Analysis of high risk factors and complications bydifferent delivery ways of premature delivery at≤34 gestationalweeksObjectiveThe high risk factors of preterm birth at≤34 gestational weeks is to be investigated and the complications caused by different delivery ways is to be compared, aiming to find the proper method to prevent premature birth≤34 gestational weeks, and the optimized delivery way if that unavoidable.Methods1,The clinical delivery cases at≤34 gestational weeks during the period from January,1994 to December, 2005 were retrospectively studied, including 112 cases by surgical uterine-incision and 115 cases by spontaneous vaginal delivery. The high risk factors of those premature birth at≤34 gestational weeks were evaluated, and the postpartum hemorrhage, the volume of postpartum hemorrhage and puerperal disease rate were analyzed by applying x²-tests.2, Diagnostic standardsi names of all cases referred to the textbook of obstetrics and gynecology, the sixth edition, by Jie Le.3, The standards to be ruled out: the premature cases which are induced by fetal death at the late trimester of pregnancy, abnormal embryo, induction delivery due to birth control and some unknown factors were ruled out.4, SPSS 13.0 statistical package was performed. All measurement data were indicated as (?)±s and independent t test were applied, while the count data, as percentage, x² -test.Results1, High risk factors of premature delivery at≤34 gestational weeks: Multiple factors co-contribute to premature delivery and most of premature delivery may be caused by two or more high risk factors. Premature rupture of membrane is at the fist place of premature delivery (40.5%), twin pregnancy (21.1%), gestational hypertension (17.2%), placenta praevia is also an important reason of premature delivery. All above suggest that the emphasis of preventing premature delivery will be placed on the education of hygiene and procreation knowledge in adolescent age, the effective propaganda of contraception knowledge, the regulation of systematic and effective antenatal examination, the reinforcement of maternal and child health organization at primary level, the execution of popular antenatal examination, the good antenatal care and the management of high risk pregnancy.2, Under the premises of more high risk factors of postpartum hemorrhage in uterine-incision delivery group, there is no statistical difference of postpartum hemorrhage rate, the blood volume of postpartum hemorrhage and puerperal disease rate between uterine-incision and spontaneous vaginal delivery groups. Therefore, uterine-incision delivery is a better delivering way for puerperal than spontaneous vaginal delivery, given the condition of the high risk factor of postpartum hemorrhage.The second part: The relationship between the complication of the preterm infant during near and far period and the different delivery waysObjectiveThe relationship between the complication of the preterm infant during near and far period and the different delivery ways at≤34 gestational weeks was compared and analyzed. The correlated high risk factors for the death of premature infant and postnatal comprehensive study ability were also evaluated, aiming to explore the best delivery ways and the proper pregnancy weeks having less influence to those preterm infant at≤34 gestational weeks.Methods1,134 cases of preterm infants born by way of the surgical uterine-incision at≤34 gestational weeks during the period from January, 1994 to December, 2005 were retrospectively studied. For the reason of statistical analysis, 141 cases of preterm infants born at≤34 gestational weeks by spontaneous vaginal delivery were randomly selected as the control group at the same time. premature infants as control group at the same time. All the cases came from the newborn infant department of Nanfang hospital or Zhujiang hospital.2,The groups of investigated objects: According to different delivery ways, all the preterm infants were divided into two groups, including 134 cases by surgical uterine-incision, 22 twins among them, and 141 cases by spontaneous vaginal delivery, 26 twins among them. They were also divided into four groups according to the birth weight, (＜1500g,1500-2000g,2000-2500g and＞2500g), while divided into three groups according to the gestational weeks, (28-30⁺⁶weeks,31-32⁺⁶weeks and 33-34⁺⁶week). Then the deaths of premature infants were discussed.3,Diagnostic standards: names of all cases referred to the textbook of obstetrics and gynecology, which was the sixth edition by Jie Le, and the practical neonatology, the third edition, by Han-Zhen Jin et al.4,The standards to be ruled out: same as the first part.5,The relations between the death rate of preterm infants at≤34 gestational weeks and different delivery way (uterine-incision and vaginal delivery) or different birth weight and gestational weeks were compared. The recent complications of preterm infants at≤34 gestational weeks except for the death, such as NRDS, death, scleredema, inhalation pneumonia of newborn, et al, were contrasted with the uterine-incision delivery and spontaneous vaginal delivery. Through letters and telephone, the information of present body heights and synthetic study ability of premature infants were obtained. The correlation between their high risk factors and complications in the near and far period was also evaluated.6,SPSS 13.0 statistical package was performed. All count data were indicated as percentage and tested by x²-test. Correlation factor analysis was used by multiple logistic stepwise regression analysis. Results1,There is statistical difference in neonate Aparg's scores, NRDS, current body height of premature infants, synthetic study ability between uterine-incision delivery group and vaginal delivery group, but there is no statistical difference in cerebral palsy of premature infants, aspiration pneumonitis, patho-jaundice, ischemia and anoxic encephalopathy, scleredema, enteritis necroticans, especially serious asphyxia between uterine-incision delivery group and vaginal delivery group. The study also shows that the premature infants' dead and complication in the near and far future have the relationship with serious asphyxia, amniotic fluid character, Apgar scores and NRDS. From it can shows, to the premature infants≤34 weeks that there is obvious difference in survival rate and complications in the near and far future between vaginal delivery and uterine-incision delivery. It shows that uterine-incision delivery is better than vaginal delivery, especially to those pregnant women who have serious pregnancy complication.2,The death rate of premature infants whose weight＜1500g and gestational weeks＜31weeks in vaginal delivery manner is higher than uterine-incision manner, but there is no difference to those premature infants whose weight≥1500g or gestational weeks≥31 weeks between uterine-incision delivery and vaginal delivery. But as the weight and gestational weeks increase, the death rate shows the descend tendency to those premature infants at the same delivery way, furthermore, the death rate descends obviously as the birth weight≥2000g, gestational weeks≥33weeks. So to those birth weight＜1500g, gestational weeks＜31weeks, the more complications could be happened, furthermore, the more treatment fee needed to those premature infants, it should weigh the factors in many ways and then choose the uterine-incision delivery.3,The high risk factors to the premature infants is amniotic fluid character, Apgar scores, NRDS, birth weight and the blood volume of postpartum hemorrhage, and have no relationship with sex, total stage of delivery, the volume of hemorrhage and amniotic fluid character have the prominent variable correlation with synthetic study ability.Conclusions1,Premature delivery is the result of co-contribution of multiple factors. Premature rupture,twin pregnancy,gestational hypertension and placenata praevia be an important reason of premature delivery. All above suggest that the emphasis of preventing premature delivery will be placed on the education of hygiene and procreation knowledge, the regulation of systematic and effective antenatal examination, the reinforcement of maternal and child health organization at primary level, the good antenatal care and the management of high risk pregnancy.2,As to the pregnant women, the way of uterine-incision delivery is better than that of spontaneous vaginal delivery, given the condition of high risk factor of postpartum hemorrhage.3,There is a positive correlation between the death and gestational weeks or birth weight of preterm infant. The lesser birth weight and gestational weeks, the higher death rate. When the birth weight is≥2000g, or the gestational weeks is≥33weeks, the death rate decreases obviously; As to the preterm infant having birth weight＜1500g or gestational weeks＜31 weeks, their death rates by spontaneous vaginal delivery is higher than those by uterine-incision delivery. There is obvious difference in the long-dated influence of preterm infants at=34 gestational weeks by using uterine-incision delivery and spontaneous vaginal delivery, especially to those pregnant women who have serious complications.4,The high risk factors to the premature infants is amniotic fluid character, Apgar scores, NRDS, birth weight and the blood volume of postpartum hemorrhage, and have no relationship with sex, total stage of delivery, the volume of hemorrhage and amniotic fluid character have the prominent variable correlation with synthetic study ability.5,The research show that when the gestational weeks =34, the way of uterine-incision delivery is better than that of spontaneous vaginal delivery. therefore, uterine-incision delivery should be selected at the basis of merits and demerits.