The effects of delayed cord clamping in preterm infants: a meta-analysis

Objective To study the short-term effects of delayed cord clamping (DCC) in preterm infants. Method A thorough search was conducted on medical databases including Cochrane Library, PubMed, Ovid, Medline, VIP citation databases, Wanfang database and CNKI. Randomized control trials (RCTs) of DCC in preterm infants were retrieved from medical literature published during January 1, 2000 to January 1, 2016 . DCC group had cord clamping 30~60 s after birth, and immediate cord clamping (ICC) group had cord clamping within 30 s after birth. Methodological quality was evaluated using Cochrane Handbook for systematic reviews and RevMan 5.1 software. Meta-analysis was performed using RevMan 5.1software. Result Seventeen RCTs were included. Meta-analysis showed that: the blood pressure within 4 hours after birth (WMD=2.49, 95%CI 0.74~4.24), the hemoglobin concentration (WMD=15.92, 95%CI 6.37~25.47) and the hematocrit (WMD=4.84, 95%CI 3.47~6.22) within 24 hours after birth in the DCC group were higher than the ICC group, P 0.05). Conclusion DCC is safe and feasible for premature infants, and can improve the outcome of premature infants. Key words: Umbilical cord; Ligation; Infant, premature; Delayed cord clamping; Meta-analysis