Cochrane Update: Effect of timing of umbilical cord clamping at birth of term infants on mother and baby outcomes.

摘要

BACKGROUND: Policies for timing of cord clamping vary, with early cord clamping generally carried out in the first 60 seconds after birth, whereas later cord clamping usually involves clamping the umbilical cord greater than one minute after the birth or when cord pulsation has ceased. OBJECTIVES: To determine the effects of different policies of timing of cord clamping at delivery of the placenta on maternal and neonatal outcomes. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Child Birth Group's Trials Register (December 2007). SELECTION CRITERIA: Randomized controlled trials comparing early and late cord clamping. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial eligibility and quality and extracted data. MAIN RESULTS: We included 11 trials of 2,989 mothers and their babies. No significant differences between early and late cord clamping were seen for postpartum hemorrhage or severe postpartum hemorrhage in any of the five trials (2236 women) which measured thisoutcome (relative risk (RR) for postpartum hemorrhage 500 mls or more 1.22, 95% (CI) 0.96 to 1.55). For neonatal outcomes, our review showed both benefits and harms for late cord clamping. Following birth, there was a significant increase in infants needing phototherapy for jaundice (RR 0.59, 95% CI 0.38 to 0.92; five trials of 1,762 infants) in the late compared with early clamping group. This was accompanied by significant increases in newborn hemoglobin levels in the late cord clamping group compared with early cord clamping (weighted mean difference 2.17 g/dL; 95% CI 0.28 to 4.06; three trials of 671 infants), although this effect did not persist past six months. Infant ferritin levels remained higher in the late clamping group than the early clamping group at six months. AUTHORS' CONCLUSION: One definition of active management includes directions to administer an uterotonic with birth of the anterior shoulder of the baby and to clamp the umbilical cord within 30-60 seconds of birth of the baby (which is not always feasible in practice). In this review delaying clamping of the cord for at least two to three minutes seems not to increase the risk of postpartum hemorrhage. In addition, late cord clamping can be advantageous for the infant by improving iron status which may be of clinical value particularly in infants where access to good nutrition is poor, although delaying clamping increases the risk of jaundice requiring phototherapy.