Umbilical cord clamping in the early phases of the COVID-19 era - A systematic review and meta-analysis of reported practice and recommendations in guidelines

OBJECTIVES: In the beginning of the COVID-19 pandemic, delayed umbilical cord clamping (CC) at birth may have been commonly discouraged despite a lack of convincing evidence of mother-to-neonate SARS-CoV-2 transmission. We aimed to systematically review guidelines, reports of practice and to analyze associations between timing of cord clamping and mother-to-neonate SARS-CoV-2 transmission during the early phases of the pandemic.

METHODS: Major databases were searched December 1, 2019 to July 20, 2021.

INCLUSION: studies and guidelines describing cord clamping practice in women with SARS-CoV-2 infection during pregnancy until two postnatal days, giving birth to live born neonates.

EXCLUSION: no extractable data. Two reviewers independently screened studies for eligibility and assessed study quality. Pooled prevalence rates were calculated.

RESULTS: Forty-eight studies (1476 neonates) and 40 guidelines were included. Delayed CC was recommended in 70.0% of the guidelines. Nevertheless, delayed CC was reported less often than early CC: 262/1476 (17.8%) vs. 511/1476 (34.6%). Neonatal SARS-CoV-2 positivity rates were similar following delayed (1.2%) and early CC (1.3%). Most SARS-CoV-2 transmissions (93.3%) occurred in utero.

CONCLUSION: Delayed CC did not seem to increase mother-to-neonate SARS-CoV-2 transmission. Due to its benefits, it should be encouraged even in births where the mother has a SARS-CoV-2 infection.