By Maria F. Gallo, PhD
Professor and Associate Dean of Research, College of Public Health, Division of Epidemiology, The Ohio State University, Columbus
SYNOPSIS: Both breast milk feeding during the postpartum hospital stay and infant rooming-in during this time were common in the five states studied from March 29 to Dec. 31, 2020, among the births that occurred to women who had a laboratory-confirmed case of SARS-CoV-2 during their pregnancy.
SOURCE: Lewis EL, Smoots AN, Woodworth KR, et al. Breast milk feeding of infants at birth among people with confirmed SARS-CoV-2 infection in pregnancy: SET-NET, 5 states, March 29, 2020-December 31, 2020. Am J Public Health 2022;112:S787-S796.
There were calls at the beginning of the COVID-19 pandemic for a cautious approach toward the possibility of exposing newborn infants to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. In February 2020, the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics (AAP) recommended that birthing parents with suspected or confirmed infection with SARS-CoV-2 consider separating from their infant and expressing their milk for feeding. Over time, evidence grew on the effectiveness of measures for the prevention and control of the virus, including having the birthing parent wear a face mask. As a result, in summer 2020, both groups revised their recommendations to promote feeding directly at the breast and having infants stay in the same room with their birth parent during their hospital stay.1,2 The practice of “rooming-in” is known to promote parental bonding with the infant and learning to respond to feeding cues, which can help establish early success at breast milk feeding.3
Lewis and colleagues sought to understand breast milk feeding practices during the beginning of the pandemic. Specifically, they set out to measure the frequency of starting breast milk feeding during the postpartum hospital stay among mothers who had a known SARS-CoV-2 infection during their pregnancy, to describe the trends in starting breast milk feeding during the postpartum hospital stay (overall and by rooming-in status) during the beginning of the pandemic, and to better understand who was engaging in this early breast milk feeding. To do this, they conducted a secondary analysis of data collected by the Surveillance for Emerging Threats to Mothers and Babies Network (SET-NET). SET-NET brings together information on mother-baby pairs from existing sources, including vital statistics, electronic medical records, laboratory data, and health department investigations and case reports.4 The authors used data from the five states taking part in SET-NET that had information on breast milk feeding.
Lewis et al studied the deliveries that occurred from March 29 to Dec. 31, 2020, among mothers who had tested positive with a molecular test for SARS-CoV-2 during their pregnancy. They included only deliveries that resulted in a live birth that survived the first day because, otherwise, the infant might not have had the possibility of starting breast milk feeding. They excluded those with multiple gestation pregnancies because these births often are less likely to be fed with breast milk. They divided the sample of mothers into two groups based on whether their first day of testing positive occurred within 14 days of their delivery or earlier than 14 days. The threshold was set at 14 days because, at the time of the study in 2020, quarantine periods were supposed to last 14 days following the first positive test.
The authors defined breast milk feeding based on whether the infant received during their hospital stay any amount of colostrum or breast milk produced by the mother. Milk donated by others did not count. The feeding could have come directly from the breast or by any other method, such as using a bottle or syringe. Breast milk feeding information came from birth certificates or medical records. They used adjusted prevalence ratios (aPR) to test for differences by timing of the maternal infection and adjusted for five factors: maternal age, race/ethnicity, health insurance at delivery, education, and gestational age. Two of the participating states (Massachusetts and Tennessee) used random sampling to select the mother-baby pairs for SET-NET; thus, the authors used weights in their analyses to account for the cases’ probability of selection and nonresponse for each state. The other three states (Minnesota, Nebraska, and Pennsylvania) included all eligible pairs and no weighting was needed.
Among the singleton live births in the five study states in 2020, the authors found 4,618 mothers who had had a laboratory-confirmed case of SARS-CoV-2 infection during their pregnancy. The infections occurred in the first trimester (25.5%), second trimester (32.4%), or third trimester (42.1%). Only 18.1% of the infections occurred within the 14-day period before delivery.
Overall, 86.5% (95% confidence interval, 82.4% to 87.6%) of mothers fed breast milk to their infant during the hospital stay following birth. However, breast milk feeding was lower among those whose SARS-CoV-2 infection took place in the 14 days before birth (78.1%) compared to those whose infection came earlier in their pregnancy (88.3%). The difference was statistically significant in the unadjusted and adjusted analyses. The difference appeared to be driven by feeding practices during the beginning of the pandemic. That is, in April and May 2020, breast milk feeding among those with infection in the 14 days before delivery was statistically significantly lower than in those with earlier infection, but this difference was not statistically significant in June to December 2020.
Most infants (76.3%) roomed-in with their mother during the hospital stay following birth. Rooming-in was lowest at the beginning of the pandemic. In April 2020, rooming-in occurred among 24.5% of mothers with infection in the 14 days before delivery and 40.7% of those with infection earlier in their pregnancy. Rooming-in was more common among those who fed their infant breast milk (89.4%) compared to those who did not use breast milk feeding (77.6%). Among the subset who roomed-in, the association between timing of SARS-CoV-2 infection and the use of breast milk feeding was not statistically significant.
COMMENTARY
Historically, the discovery of new infections often has been accompanied by concerns about the potential for vertical transmission to the infant through breast milk feeding. For example, the first decades of the human immunodeficiency virus epidemic were marked by much controversy over the best guidance for infant feeding.5 Similarly, the start of the COVID-19 pandemic was a time of much uncertainty. Much was unknown about the virus, and this led to recommendations for steps to try to protect newborns against infection. These concerns, though, have to be balanced against the many benefits that breast milk is known to confer. In this case, the benefits also could include the possibility that people with a history of infection or vaccination could transmit antibodies against COVID-19 through their breast milk to the infant. Our knowledge grew during the pandemic, and a review of the evidence showed that neonatal infection with SARS-CoV-2 was uncommon and that mothers feeding from the breast and rooming-in with the infant appeared to be safe.6
Lewis and colleagues showed that, among women who had had SARS-CoV-2 infection during pregnancy, both breast milk feeding during the immediate hospital stay following birth and the infant rooming-in with the mother appeared to be common in 2020. In the early months (April and May 2020), early breast milk feeding was lower among mothers whose infection occurred within the 14 days preceding delivery compared to those who were infected earlier during their pregnancy.
However, this difference did not appear to persist during the rest of 2020. This difference also was not detected among the mothers who had their infant room-in with them. This finding could support the importance of rooming-in for early breast milk feeding or, on the other hand, it could suggest that those who are more strongly committed to breast milk feeding are more likely to also practice rooming-in.
The authors used data from a surveillance system that was started in 2019 to monitor the effects of emerging, and reemerging, threats on pregnant people and their infants. The COVID-19 pandemic has underscored the importance of creating and maintaining robust surveillance systems. This analysis was a creative use of existing data to help us better understand breast milk feeding practices among women who had SARS-CoV-2 infection during pregnancy. A primary limitation was that the authors did not have a control group of women without SARS-CoV-2 infection during their pregnancy. Although they found a prevalence of initiation of breast milk feeding in 2020 that appeared to be similar to rates in earlier years, making comparisons to historical data is complicated by the fact that breast milk feeding rates can vary by population characteristics. A second limitation is that, because of the study timeframe, the authors only studied women who were infected with one of three variants: Alpha, Beta, or Gamma. Surveillance will remain critical to ensure that future variants do not pose new risks to pregnant people or their infants.
Our terminology for people and their behaviors and practices continues to evolve over time. Lewis and colleagues used the phrase “breast milk feeding” instead of terms such as “nursing” or “breastfeeding” because the latter do not account for the range of ways in which infants are fed with human milk.7 The development of affordable, effective breast pumps has allowed people to feed their infants with breast milk when, in the past, they might not have been able or willing to feed directly at the breast for a variety of reasons. It is important for researchers to use clear language when defining and reporting on study findings, and the authors were careful to do so here. On the other hand, they referred to the study sample as both “people” (e.g., in the title and other sections of the article) and elsewhere as “mothers.” Because the authors used data from a surveillance system (rather than surveying people to collect their information for the present study), the sample probably included birthing people regardless of whether they self-identified as a woman. However, the unclear terminology used in the article introduces ambiguity here.
Overall, the article findings show that in 2020 early breast milk feeding and rooming-in among those who had SARS-CoV-2 during pregnancy were common. Healthcare providers should continue to support breast milk feeding and rooming-in for people regardless of their SARS-CoV-2 infection status.
REFERENCES
- Centers for Disease Control and Prevention. Evaluation and management considerations for neonates at risk for COVID-19. Last reviewed May 19, 2020. https://stacks.cdc.gov/view/cdc/88194
- American Academy of Pediatrics. FAQs: Management of infants born to mothers with suspected or confirmed COVID-19. Last updated Nov. 10, 2022. https://www.aap.org/en/pages/2019-novel-coronavirus-covid-19-infections/clinical-guidance/faqs-management-of-infants-born-to-covid-19-mothers/
- World Health Organization. Guideline: Protecting, promoting and supporting breastfeeding in facilities providing maternity and newborn services. WHO; 2017.
- Woodworth KR, Reynolds MR, Burkel V, et al. A preparedness model for mother-baby linked longitudinal surveillance for emerging threats. Matern Child Health J 2021;25:198-206.
- Gribble K, Mathisen R, Ververs M-T, Coutsoudis A. Mistakes from the HIV pandemic should inform the COVID-19 response for maternal and newborn care. Int Breastfeed J 2020;15:67.
- Walker KF, O’Donoghue K, Grace N, et al. Maternal transmission of SARS-COV-2 to the neonate, and possible routes for such transmission: A systematic review and critical analysis. BJOG 2020;127:1324-1336.
- Rasmussen KM, Felice JP, O’Sullivan EJ, et al. The meaning of “breastfeeding” is changing and so must our language about it. Breastfeed Med 2017;12:510-514.
