COVID during pregnancy poses a low risk to newborns, new research shows
Since the start of the COVID-19 pandemic, there has been great concern about how to protect the most vulnerable—particularly newborns. In past pandemics, newborn babies and young people have been at an increased risk of disease and death. This has probably influenced COVID-19 guidelines in hospitals and healthcare systems.
A recently published global survey found that newborns were being separated from their mothers in half the world's countries last year as a precautionary measure if the mother had tested positive for COVID-19. Separating a baby from its mother at birth can have negative consequences for the health of both the mother and baby. This must be weighed against the possible benefits of keeping them apart.
Yet more than a year into the pandemic, the outcomes for babies born to mothers who have had COVID-19 remain largely unknown and unreported, putting great stress on families and healthcare providers.
With this in mind, my colleagues and I—working with the Public Health Agency of Sweden—tried to gain a better understanding of the potential risks to babies whose mothers tested positive for coronavirus during pregnancy or childbirth.
We were able to do this because, during the pandemic in Sweden, the separation of mothers and infants at birth has only been practiced if either was unwell, with breastfeeding allowed if following strict hygiene procedures.
Analyzing a year's data
Our study looked at daily reports made to three Swedish registries: the National Quality Register for Pregnancy, the National Quality Register for Neonatal Care, and the Communicable Diseases Register. By cross-referencing these, it was possible to monitor and report outcomes for babies during both the first and second waves of COVID-19.
Altogether, we captured the outcomes of 92% of all babies born in Sweden between March 11 2020 and January 31 2021. This accounted for almost 90,000 births, making this one of the largest datasets on this subject to date. We found that 2,323 babies were born during this period to mothers who had tested positive for COVID-19 during pregnancy, with 642 mothers (28%) testing positive at the time of delivery.
All babies born to mothers who had tested positive were themselves tested between 12 and 24 hours after birth. For babies admitted to a neonatal unit, COVID-19 tests were repeated at 48 and 96 hours after birth. Only 21 babies (0.9%) tested positive for COVID-19, most of them without displaying any symptoms. A few babies were treated for reasons other than COVID-19.
However, babies born to mothers who had had COVID-19 were more likely to be admitted to neonatal care and to experience respiratory problems. This, though, can be explained by the higher number of preterm births in the COVID-19 group than in the comparison group. We found no direct link between maternal infection and neonatal respiratory infection or pneumonia.
That said, our study adds to the evidence that women testing positive for COVID-19 are at increased risk of preterm birth. In our study, 8.8% of women who were COVID-positive during pregnancy delivered preterm, compared with 5.5% of those who were COVID-negative.
We also found that COVID-19 in the mother was not associated with the death of the child. Seven infants born to mothers who had had COVID-19 died, all from causes unrelated to COVID-19, with none of these infants testing positive for the disease. There was also no difference in the mortality rate of those babies born to mothers who were COVID-positive and COVID-negative during pregnancy.
No need to separate
Our study, therefore, supports a recommendation that babies born to women who have tested positive for COVID-19 while pregnant or during delivery do not need to be routinely separated from their mothers at birth. Babies are very unlikely to be infected or to suffer ill health as a result of their mother having or having had COVID-19.
Our research also showed that breastfeeding seems to be safe: 94% of women in the COVID-19 group were breastfeeding their babies at hospital discharge, with 99% of their infants testing negative. The small number of infants that were infected showed no signs of infection.
Although not all countries are like Sweden—there are population differences as well as country-specific differences in healthcare and COVID-19 levels—our work should reassure pregnant women in other countries (and their families) that a coronavirus infection during pregnancy poses a low risk.