COVID-19 Evidence Alerts
from McMaster PLUSTM

Current best evidence for clinical care (more info)

COVID-19 Evidence Alerts needs your support. If our service is of value to you, please consider donating to keep it going. Learn more Donate now

Prognosis Deniz M, Tezer H Vertical transmission of SARS CoV-2: a systematic review. J Matern Fetal Neonatal Med. 2020 Jul 21:1-8. doi: 10.1080/14767058.2020.1793322.

OBJECTIVE: The aim of this study is to review the current evidence on the vertical transmission of SARS CoV-2.

METHODS: Combination of the following keywords; COVID-19, SARS CoV-2, placenta, vertical transmission, intrauterine infection, breast milk were searched in databases.

RESULTS: In the 50 studies included, 17 newborns testing positive for SARS CoV-2 by RT-PCR were reported. In three neonates, SARS-CoV-2 IgG and IgM levels were elevated. Eight placental tissues testing positive for the virus were reported. Three positive RT-PCR results of test of breast milk have been reported recently. One amniotic fluid testing positive was reported.

CONCLUSION: Possible vertical transmission of SARS CoV-2 has been observed in some studies currently. More RT-PCR tests on amniotic fluid, placenta, breast milk and cord blood are required.

Discipline / Specialty Area Score
Pediatric Neonatology
Family Medicine (FM)/General Practice (GP)
Infectious Disease
Comments from MORE raters

Family Medicine (FM)/General Practice (GP) rater

There are still too many doubts!

Family Medicine (FM)/General Practice (GP) rater

More study is required.

Infectious Disease rater

This systematic review summarizes evidence for vertical transmission of COVID-19. Unfortunately, although the review is systematic, it lacks synthesis and balance. E.g. the authors do not provide a summary percentage of neonates with (any) evidence of COVID-19 infection in the results. You have to go through each study in the discussion to find relevant information. In addition, in the single table of the review, the authors have included only the studies which provide evidence for vertical transmission, that is only 17 out of 50 studies included in the review. Thus, probably the largest study with over 100 pregnant women, has not been included because it suggests that vertical transmission during the 3rd trimester of pregnancy is unlikely. In conclusion, this review provides evidence that vertical transmission is possible, but further information (e.g. risk of abortion or preterm delivery, possible neonatal sequelae) is difficult to extract.

Obstetrics rater

The results of this review showed that the risk of vertical transmission of SARS CoV-2 is possible, but not high. This is a useful information to pregnant women.

Pediatric Neonatology rater

Timely topic with a lot of unknowns.