Effect Of Delayed Cord Clamping On Cerebral Flow In Preterm Infants

Objective: To study the effects of delayed vs immediate cord clamping on cerebral flow in preterm infants.Methods: This trial is a prospective,noninvasive study.Preterm infants who met the inclusion and exclusion criteria were divided into DCC group and ICC group according to the umbilical cord ligation completed in the obstetrics department.The hemodynamic indexes of the middle cerebral artery and the anterior cerebral artery,including(peak systolic velocity,end diastolic velocity,resistance index),were measured by Mindray M9 color ultrasound within 1h,24±1h,48±1h,and 72±1h after birth,respectively.The study also collected the red blood cells,hemoglobin,hematocrit,and total bilirubin values of the first(within two hours after birth)and second postnatal subjects(the fifth day after birth),as well as the rate of mild and severe intraventricular hemorrhage from follow-up to discharge.Results:A total of 118 premature infants were included in the trial,and 1 case in the ICC group was required to be discharged during hospitalization,so 60 cases were actually included in the ICC group and 57 cases were included in the DCC group.It exhibited that the baseline characteristics between the two groups of infants was no significant difference(P>0.05).At four different time points,there was no significant difference in PSV,EDV and RI between the DCC group and the ICC group in the overall and stratified gestational age groups(P>0.05);It showed that the interaction between groups and time was no significant difference(P>0.05).At four different time points,there was no significant difference in the PSV,EDV and RI of the anterior cerebral artery between the DCC group and the ICC group in the overall and stratified gestational age groups(P>0.05).It displayed that the interaction between groups and time was no significant difference(P>0.05).The middle cerebral artery PSV and EDV of the DCC group and the ICC group as a whole and after stratification increased with the increase of age(P<0.05).The PSV and EDV of the anterior cerebral artery in the DCC group and the ICC group as a whole and after stratification increased with the increase of age(P<0.05).On the first day after birth,the red blood cells,hemoglobin,and hematocrit in the DCC group were higher than those in the ICC group(P<0.05).However,there was no statistical difference between the two groups in the total bilirubin on the first day after birth,the total bilirubin on the fifth day and intraventricular hemorrhage during hospitalization(P>0.05).Conclusion: DCC does not affect cerebral blood flow in preterm infants,but can increase the number of red blood cells,hematocrit,hemoglobin,and improve postnatal anemia in preterm infants without increasing the incidence of jaundice.This shows that DCC is a safe way of placental blood transfusion.