- Researchers say it’s rare for the coronavirus that causes COVID-19 to be transmitted from mother to infant before birth.
- Experts say it’s important to practice safety protocols such as mask wearing and handwashing after a baby is born.
- Experts also recommend new mothers breastfeed their infants, if possible, because the nutrients can provide a protective benefit.
All data and statistics are based on publicly available data at the time of publication. Some information may be out of date.
Being pregnant amid a pandemic adds an extra layer of stress to what’s already a stressful time.
However, new research suggests that mothers-to-be can breathe a sigh of relief when it comes to COVID-19 transmission from moms to their infants.
Mothers who contract SARS-CoV-2 only rarely transmit the virus to their children in utero or even after birth, as long as proper hygiene practices are followed.
This is according to a new small study conducted by researchers at the Columbia University Irving Medical Center and NewYork-Presbyterian Morgan Stanley Children’s Hospital found.
Out of 101 newborns born to COVID-19-positive moms, just two tested positive for the virus. Of those two infants, neither showed signs of illness, the
“For many other viral infections, if the mom is sick with the virus, she can pass it on to her newborn through a process called vertical transmission (direct mom to baby transmission),” said Dr. Kimberly Kilby, a family and preventive medicine physician who works as a regional medical director at MVP Health Care and was a previous director of Communicable Disease Control at the New York Department of Health during the H1N1 flu pandemic.
“So far, for COVID-19, there does not appear to be a significant vertical transmission,” Kilby told Healthline.
In addition, “for other viral infections, pregnancy often means that moms are at increased risk of complications, such as preterm labor or more severe illness,” she said. But in this study, the mothers with serious COVID-19 symptoms delivered only about 1 week earlier than the mothers with mild or no symptoms.
“We now know that infants do get COVID-19 from their infected mothers — it’s just not very common, but it does happen,” Dr. Mark Schleiss, a professor at the University of Minnesota Medical School and investigator at the Institute for Molecular Virology, told Healthline. “It happens by two routes: across the placenta while the baby is still in the womb and after birth from face-to-face contact.”
Why COVID-19 appears to be less communicable from mother to baby than some other viruses is unclear, though there are theories.
“Not every disease passes from mom to fetus or from mom to baby during delivery,” Kilby said. “The diseases with the highest risk of passing in these ways are commonly screened for in prenatal care, such as group B streptococcus, herpes simplex, and HIV.”
“The short answer is, ‘we don’t know.’ The science seems to suggest that infants don’t express the receptor on cells for the virus on their cells, the so-called ACE-2 receptor. Thus, at the level of the virus-cell surface interface, the infection can’t ‘take’ or ‘start,’” he explained.
“Infants also have higher lymphocyte counts than adults, and many fundamental differences in immune cells and responses,” he added. “Thus, the immune response may be more ‘protective’ than in older children or adults.”
Interest in home births has risen steadily since the beginning of the pandemic, perhaps because of the potential dangers of contracting COVID-19 in a hospital setting and worries about potential restrictions on mother-infant contact.
But this study’s findings show that only minor measures need to be taken to protect newborns from COVID-19 transmission.
“Our findings should reassure expectant mothers with COVID-19 that basic infection-control measures during and after childbirth — such as wearing a mask and engaging in breast and hand hygiene when holding or breastfeeding a baby — protected newborns from infection in this series,” said Dr. Cynthia Gyamfi-Bannerman, MSc, a senior study author and a maternal-fetal medicine expert at NewYork-Presbyterian/Columbia University Irving Medical Center in a press release.
These findings, combined with previous research showing that COVID-19 doesn’t appear to make its way into the breast milk in an infectious form, provide encouraging news for practicing healthy mother-infant relationships immediately postpartum.
In fact, breastfeeding might even have protective benefits, Kilby said.
“Breast milk is known to be protective against numerous pathogens,” she said. “However, most studies have not found the COVID-19 virus in breast milk, but the milk has been found to contain an antibody to the COVID-19 virus in some studies.”
So while there’s much that’s still unknown, it seems that giving birth in the hospital is safe for the baby and can still follow a nurture-based approach, even if those new mothers test positive for COVID-19.
“This study endorses the benefits of rooming-in, establishing breastfeeding, and delaying bathing on newborn outcomes, and suggests that separating mothers positive for SARS-CoV-2 and their newborns and avoiding direct breastfeeding may not be warranted to prevent SARS-CoV-2 transmission,” the study authors write.