The Importance of Collecting Data on Pregnant Women and Infants During Public Health Emergencies

November 30, 2020|4:57 p.m.| Karen Remley, MD, MBA, MPH, FAAP | Director of the National Center on Birth Defects and Developmental Disabilities, CDC

Karen Remley, MD, MBA, MPH, FAAPThe COVID-19 pandemic has impacted virtually every aspect of life, every demographic, and every geographic region, and key components of the historic response have been understanding who is at greatest risk for severe illness and death, along with the long-term consequences of infection. We’ve learned from previous emergency responses that pregnant women and infants can be disproportionately affected by emerging infectious diseases, like Zika virus and H1N1 influenza. New data available underscore the importance of monitoring pregnant women and their infants during the COVID-19 pandemic to better inform public health action and clinical guidance and protect their health.

A recent article published in November in CDC’s Morbidity and Mortality Weekly Report (MMWR) demonstrates stronger and more consistent evidence that pregnant women are at increased risk for severe illness from COVID-19. Although the absolute risks are thankfully low overall, pregnant women are at increased risk of severe illness with COVID-19 when compared with non-pregnant women of reproductive age. Specifically, this article found that pregnant women with COVID-19 were more likely to be admitted to the intensive care unit, receive invasive ventilation, receive extra-corporeal membrane oxygenation (an advanced life support technique used for patients with life-threatening heart and/or lung problems), or die. These findings are biologically plausible, because we know that women experience changes during pregnancy which affect heart and lung function, immunity, and blood clotting in ways which may increase risk for severe illness.

From a complementary MMWR report, using data from the Surveillance for Emerging Threats to Mother and Babies Network (SET-NET), authors found that pregnant women with COVID-19 might be at increased risk of having a preterm infant. They also found that among the 610 infants with postnatal molecular testing results, 2.6% were positive for SARS-CoV-2 infection, the virus that causes COVID-19 results. These infants were primarily born to women with infection near the time of delivery. While this study provided information on pregnant women late in pregnancy and infants at delivery, more information is needed on women with infection early in pregnancy and infant health beyond delivery.

Monitoring the Effects of Emerging Infections on Mothers and Babies
Identifying risks among pregnant women has always been challenging—available data sources usually have limited information on pregnancy status, and there is an inherent time delay from identifying a potential exposure during pregnancy to observing a potential health outcome at birth and in an infant. However, when COVID-19 hit in early 2020, CDC was uniquely positioned to collect data on infection during pregnancy through SET-NET supported through CDC’s National Center on Birth Defects and Developmental Disabilities. This linked longitudinal surveillance approach was adapted from the 2016 Zika virus outbreak, where state, local, and territorial health departments collaborated with CDC to collect data on pregnant women with Zika and their infants.

While the CEO of the American Academy of Pediatrics, I worked closely with pediatricians across the country and saw firsthand the utility of this information to inform state and local programs and services for affected families. Data collected through this approach allowed us to partner with the CDC in answering key questions, develop guidance for healthcare providers, and build better advice for pregnant women, parents, and families.

In 2019, its first year, SET-NET not only continued to collect information about Zika virus infection and long-term outcomes among children, but also expanded to include congenital exposure to hepatitis C and syphilis. As part of CDC’s COVID-19 response, SET-NET has rapidly adapted once again to address this novel virus. For this recent report from SET-NET, 16 participating jurisdictions reported information on pregnancy and infant outcomes among women with laboratory-confirmed SARS-CoV-2 infection. Information comes from existing data sources by linking data reported through electronic laboratory reporting, birth certificates, maternal medical records, and infant medical records. The linked longitudinal approach allows us to follow pregnant women with COVID-19 through delivery and their infants through six months of age to understand health effects that may not be apparent at birth. SET-NET data holds promise for helping us answer questions about the risks of COVID-19 during pregnancy, including the effects from infection early in pregnancy and the longer-term outcomes among infants.

Partnering Locally and Nationally
To accomplish both reports, we saw impressive collaboration among colleagues working in the fields of maternal and child health, birth defects, and infectious disease, all partnering together to conduct COVID-19 surveillance in pregnancy.

After sending an introductory letter and proposal to state epidemiologists and state maternal and child health directors, CDC received overwhelming interest in this optional surveillance opportunity to monitor pregnant women with COVID-19, and participating health departments began developing their approaches for collecting data. On monthly data-use working group calls, several health department partners share their surveillance approaches and lessons learned, including approaches for data linkages to existing data sources to better determine pregnancy status and obtain outcome information, best practices for conducting medical record abstraction, and engagement with hospital systems for collection of data.

Using Data to Inform Action
These data are important to counsel pregnant women about the potential risks of COVID-19 to themselves, their pregnancies, and their infants. Public health and healthcare professionals should continue to encourage pregnant women and their families to follow measures to prevent the spread of COVID-19, including frequent hand washing, mask use, and social distancing. Additionally, women should be encouraged to keep all prenatal and postpartum healthcare appointments as well as newborn visits.

The findings from both MMWR reports underscore the importance of continued monitoring of illness severity among pregnant women as well as continued monitoring of birth and infant outcomes through SET-NET. Understanding the risks COVID-19 poses for pregnant women and their infants is essential for counseling, clinical care and treatment, and evidence-based distribution of resources. A huge thank you to all state, local, and territory health departments for working together with CDC to advance the health and well-being of pregnant women and infants.

CDC Clinical Guidance:

Additional CDC Resources:


Karen Remley, MD, MBA, MPH, FAAP, is CDC’s director of the National Center on Birth Defects and Developmental Disabilities, and is the former Commissioner of the Virginia Department of Health.