Vertical and postnatal transmission of COVID 19 – should we worry?

Contributed by Dr Bikram Das

A systematic review by Federico Fornari et al. in early phase of the pandemic analysed nine papers with a total 70 newborns of SARS COV 2 PCR positive mother. This revealed 5 out of 70 (7.1%) cases with possibility of vertical transmission as four newborns were PCR positive within 48 hours and 1 newborn was having positive IgM and IgG with a negative PCR[1]. While some studies demonstrated presence of ACE 2 receptor in the placenta and SARS-CoV-2 in amniotic fluid and fetal side of the placenta, supporting the possibility of vertical transmission, other articles pointed towards the possibility of direct contact with maternal stool containing the virus as a cause of PCR positivity in newborn. It is very important to find out the actual incidence of vertical transmission along with risk of mother to child transmission of COVID 19 due to breast feeding to implement isolation/separation planning and to find out the safety of direct breastfeeding when mother is at potentially infectious phase.

A recent meta-analysis by Xin Lei Goh et al. included seventeen studies where mothers who tested positive for SARS-CoV-2 by PCR and whose newborns were tested by PCR were included. The average pooled incidence of vertical transmission was 16 per 1000 newborns (95% CI 3.40 to 73.11) [2], indicating the risk of vertical transmission of SARS-CoV-2 is low. CDC recommends testing both symptomatic and asymptomatic neonates born to mothers with confirmed or suspected COVID-19, regardless of mother’s symptoms, at approximately 24 hours of age. If initial test results are negative, or not available, testing should be repeated at 48 hours of age.

Early and close contact between the mother and neonate has many well-established benefits so what should be the best practices regarding infection control in mother–newborn dyads is an important issue. A recent observational cohort study in New York including three hospitals by Christine M Salvatore et al. showed neonatal outcome in terms of serial PCR positivity in newborns who were allowed ‘rooming in’ and breast feeding practices with precautions like hand hygiene, breast cleansing, and placement of a surgical mask showed no transmission from 78 infected women [3]. Three fourths of them were symptomatic. This study depicts transmission is unlikely to occur if correct hygiene precautions are undertaken and that rooming in and breastfeeding are safe procedures when paired with effective parental education of infant protective strategies.

CDC recommends mothers should wear a mask and practice hand hygiene during all contact with their neonates including breast feeding. At other times, a physical distance of >6 feet between the mother and neonate or placing the neonate in an incubator, should be used when feasible. These precautions are to continue for a total of 10 days from the onset of symptoms in the mother or from the date of positive PCR test in an asymptomatic mother.

To summarize, vertical transmission is not a major concern as per available data. Rooming in and breast feeding with hand hygiene, breast cleansing and mask use does not increase the risk of mother to child transmission of COVID-19.

References

  1. Federico Fornari. Vertical Transmission of Covid-19-A Systematic Review. Journal of Pediatrics, Perinatology and Child Health 4 (2020): 007-013.
  2. Xin Lei Goh, Yi Fen Low etal.BMJ Arch Dis Child Fetal Neonatal Ed Month 2020.
  3. Christine M Salvatore, Jin-Young Han. Neonatal management and outcomes during the COVID-19 pandemic: an observation cohort study, Lancet Child Adolesc Health 2020.