Efficacy and safety of umbilical cord milking at birth: a systematic review and meta-analysis.

IMPORTANCE: Umbilical cord milking (UCM) is suggested to improve neonatal outcomes.

OBJECTIVES: To perform a systematic review and meta-analysis of the efficacy and safety of UCM in full-term and preterm neonates.

DATA SOURCES: A systematic search of MEDLINE, EMBASE, CINAHL, the Cochrane Database of Clinical Trials, the clinicaltrials.gov database, and the reference list of retrieved articles from 1940 to 2014.

STUDY SELECTION: Randomized clinical trials comparing UCM with other strategies of handling the umbilical cord at birth in full-term and preterm infants. Seven of the 18 initially identified studies were selected.

DATA EXTRACTION AND SYNTHESIS: Two reviewers independently extracted data and assessed the risk for bias in included trials using the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN OUTCOMES AND MEASURES: Neonatal mortality before discharge from the hospital.

RESULTS: We included 7 randomized clinical trials involving 501 infants. Infants with a gestational age of less than 33 weeks allocated to UCM compared with control conditions showed no difference in the risk for mortality (risk ratio [RR], 0.75 [95% CI, 0.35 to 1.64]; risk difference [RD], -0.02 [95% CI, -0.09 to 0.04]), hypotension requiring volume expanders (RR, 0.71 [95% CI, 0.41 to 1.25]; RD, -0.09 [95% CI, -0.22 to 0.05]), or inotrope support (RR, 0.77 [95% CI, 0.51 to 1.17]; RD, -0.10 [95% CI, -0.25 to 0.05]). Higher initial levels of hemoglobin (mean difference, 2.0 [95% CI, 1.3-2.7] g/dL) and hematocrit (mean difference, 4.5% [95% CI, 1.5%-7.4%]) were identified in the UCM groups. We found a reduced risk for oxygen requirement at 36 weeks (RR, 0.42 [95% CI, 0.21 to 0.83]; RD, -0.14 [95% CI, -0.25 to -0.04]) and for intraventricular hemorrhage of all grades (RR, 0.62 [95% CI, 0.41 to 0.93]; RD, -0.12 [95% CI, -0.22 to -0.02]) in infants assigned to UCM. Among infants with a gestational age of at least 33 weeks, UCM was associated with higher hemoglobin levels in the first 48 hours in 224 infants (mean difference, 1.2 [95% CI, 0.8-1.5] g/dL) and at 6 weeks of life in 170 infants (mean difference, 1.1 [95% CI, 0.7-1.5] g/dL).

CONCLUSIONS AND RELEVANCE: Umbilical cord milking was associated with some benefits and no adverse effects in the immediate postnatal period in preterm infants (gestational age, <33 weeks); however, further studies are warranted to assess the effect of UCM on neonatal and long-term outcomes.