Study On The Influence Of Different Umbilical Cord Ligation Methods On Preterm Infants With A Gestational Age Of<32 Weeks

ObjectiveThis research is to evaluate the benefits and risks of different umbilical cord ligation methods on preterm infants with a gestational age of<32 weeks,and provide evidence to the optimal method of umbilical cord clamping by comparing the influences of umbilical cord milking,delayed cord clamping and immediate cord clamping on these preterm infants.Methods1.Of 135 preterm infants with a gestational age of<32 weeks born at Obsterics and Gynecology Hospital Affiliated to Nanjing medical university from January 2016 to February 2017 were randomly divided into umbilical cord milking(UCM)group,delayed cord clamping(DCC)group and immediate cord clamping(ICC)group according to the inclusion and exclusion criteria,and each group of 45 cases.During the research,5 cases had fallen off because of giving up the treatment or referral,9 cases had fallen off due to birth asphyxia,and 1 case had fallen off because of the umbilical knot in the proximal fetal 25 cm.Therefore,the research had 40 cases in UCM group,42 cases in DCC group and 38 cases in ICC group.In UCM group,about 25 cm of the umbilical cord was vigorously milked towards the umbilicus three times before clamping the cord after birth.The milking speed was about 20 cm per 2 seconds.In DCC group,the cord was clamped delayed 45s,while the cord was clamped immediately in ICC group.The following indexes were analyzed among the three groups:(1)Baseline data:Hemoglobin,hematocrit and body weight within 1 day of prenatal.Gestational age,birth weight,sex and 1/5min Apgar scores of premature infants.(2)The initial Hemoglobin(Hb),hematocrit(Hct),anemia rate at one week and total amount of red blood cell transfusion before discharge.(3)The initial blood gas parameters(pH、HCO3-、sBE),mean arterial pressure and hypotension requiring expansion and boost.(4)Bilirubin peak,total time of phototherapy and incidence of pathologic jaundice as well as polycythemia before discharge.(5)The complications before discharge.2.A total of 20 premature infants with gestational age of<32 weeks were selected to measure the blood volume of 25 cm long umbilical cord by volumetric method.Results1.The three groups had no difference in Hb,Hct level and body weight of mothers(P>0.05).There was no statistical difference in the results of gestational age,birth weight,sex and 1/5min Apgar scores of premature infants(P>0.05).2.Comparison of the related indexes of anemia and blood transfusion among the three group(1)There was a significant difference in Hb(g/L)and Hct(%)level at birth and one week among the three groups(P<0.05).Hb(g/L)and Hct(%)level were significantly higher in UCM and DCC group comparing to ICC group(P<0.05).However there was no statistical difference between UCM group and DCC group(P>0.05).(2)There was a significant difference in anemia rate at one week and total amount of red blood cell transfusion among the three groups(P<0.05).Anemia rate at one week and total amount of red blood cell transfusion were significantly lower in UCM and DCC group comparing to ICC group(P<0.05).However there was no statistical difference between UCM group and DCC group(P>0.05).3.(1)There was a significant difference in standard base excess among the three groups(P<0.05).Standard base excess was significantly higher in UCM and DCC group comparing to ICC group(P<0.05).However there was no statistical difference between UCM group and DCC group(P>0.05).The three groups had no difference in pH value and HCO3-concentration(P>0.05).(2)There was a significant difference in mean arterial pressure among the three groups(P<0.05).Mean arterial pressure was significantly higher in UCM and DCC group comparing to ICC group(P<0.05).However there was no statistical difference between UCM group and DCC group(P>0.05).(3)There was a significant difference in hypotension requiring expansion among the three groups(P<0.05).Compared with the ICC group,hypotension requiring expansion was significantly lower in UCM and DCC group(P<0.05).However there was no statistical difference between UCM group and DCC group(P>0.05).4.The three groups had no difference in bilirubin peak,total time of phototherapy and the incidence of pathologic jaundice as well as polycythemia before discharge(P>0.05).5.The three groups had no difference in complications before discharge(P>0.05).6.The blood volume of 25 cm long umbilical cord is about 15.1 ml±1.43 ml(10 ml～19 ml).Conclusions1.The clinical effect of UCM(25cm,3times)was similar to that of DCC(45s),which can increase Hb as well as Hct,and reduce the anemia rate and the total amount of red blood cell transfusion.In addition,the polycythemia,pathologic jaundice,bilirubin peak and total time of phototherapy were no difference among the three groups.Therefore,UCM and DCC may be a safe and effective method to improve the prognosis of preterm infants with a gestational age of<32 weeks.2.UCM did not delay the neonatal resuscitation and further treatment with less time,which may be the optimal method of umbilical cord clamping in preterm infants with a gestational age of<32 weeks,especially asphyxiated newborns.