Analysis Of Relevant Factors Of Preterm Birth And Its Outcome

Objective:To analysis trends in preterm birth, find out the main causes of iatrogenic preterm birth , identify the risk factors of preterm birth and to research the relevant factors of neonatal asphyxia in premature infants.Methods:1.The rate of preterm birth from 2002 to 2006 were reviewed. Constituent ratio of three types of preterm birth and causes of iatrogenic preterm birth were calculated.2. The incidences of relevant factors were compared between pregnant women with preterm birth and term birth admitted in our hospital from January 2002 to December 2006.3.Data of premature infants born in our hospital from January 2002 to December 2006 were reviewed. The impact of different types of preterm birth , gestational age ,neonatal weight, and risk factors of preterm birth on neonatal asphyxia were investigated.Results:1.The rate of preterm birth from 2002 to 2006 were 6.65%, 7.24%, 6.95%,8.53%,8.47%. Constituent ratio of iatrogenic preterm birth,PPROM and idiopathic preterm birth were 20.41%~30.77%, 25.00%~33.33%, 36.84%~53.06% respectively. Constituent ratio of preeclampsia,ICP,vaginal bleeding caused by placenta previa and placental abruption,fetal distress in uterus,FGR which resulted in iatrogenic preterm birth were 28.98%, 23.19%, 14.49%,7.25%,4.35% by turns.2. The incidence of hypertensive disorder complicating pregnancy, ICP, placenta previa,placental abruption, uterus with scar, GDM, hydramnios, bigeminal pregnancy in preterm birth group were 15.63%, 17.19%, 10.94%, 3.12%, 10.94%, 7.81%, 4.92%, 6.25%, respectively, which were markedly higher than those in term birth group 2.30%, 4.17%, 3.88%, 0.29%, 1.44%, 2.01%, 0.72%, 0.43% , respectively (P<0.05).3. The incidence of asphyxia in premature infants born among 28~33+6w was significantly higher than those born among 34~36+6w (P<0.05). There was no significant difference in asphyxia between the neonates of Spontaneous preterm and iatrogenic preterm (P>0.05). Weight of premature infants with asphyxia was markedly lower than those without asphyxia (P<0.05).The incidence of risk factors of preterm birth were not significantly different between the premature infants with and without asphyxia (P>0.05).Conclusions:The trend of preterm birth was rising. The main causes of iatrogenic preterm birth were hypertensive disorder complicating pregnancy, ICP, vaginal bleeding caused by placenta previa or placental abruption,fetal distress in uterus,FGR. Hypertensive disorder complicating pregnancy,ICP, placenta previa, placental abruption, uterus with scar, GDM , hydramnios, bigeminal pregnancy were the risk factors of preterm birth . Neonatal weight and gestational age were the main effective factors on neonatal asphyxia in premature infant.Risk factors of preterm birth should be prevented .More attentions should be paid to pregnant women with the risk factors. To prolong pregnancy and increase fetal weight with the precondition of maternal and fetal safety was an effective way to improve the infant's outcome.