Published November 3, 2020
By Dr. Jane van Dis, OB-GYN and Maven’s Medical Director
The latest CDC research shines new light on the heightened risks for pregnant women due to COVID-19 with the largest CDC study on the virus during pregnancy to-date. The study suggests that pregnant women are at a heightened risk of death and severe illness if infected by COVID-19, and more likely to require admission to intensive care, compared with non-pregnant women of the same age—though there are important limitations to call out. This new data adds to growing evidence that remind us to continue to take these risks seriously. If you’re pregnant, please continue to take extra precautions to remain safe, healthy, and limit your risk of exposure to COVID-19. The CDC released this new report on Monday, adding to previously reported data, with an analysis of over 450,000 women aged 15-44 years, of whom 6.6% (30,415 women) were pregnant.
Here’s what you need to know about the latest findings
In contrast to previous CDC data, the latest research reveals pregnant women were more likely to die of COVID-19: 1.5 per 1,000 symptomatic pregnant women died of COVID, compared to 1.2 per 1,000 non-pregnant women.
This report also found that pregnant women were at slightly increased risk of needing to be connected to an ECMO machine—meaning extracorporeal membrane oxygenation, which pumps and oxygenates a patient’s blood outside the body; similar to the machine used in open-heart surgery: 17 per 1,000 for non-pregnant women versus 120 per 1,000 for pregnant women.
As has been previously reported by the CDC, researchers found that pregnant women were at increased risk of:
- ICU admission: approximately 10.5 out of 1,000 pregnant women admitted to ICUs compared to 3.9 out of 1,000 non-pregnant women admitted to ICUs
- Being placed on a ventilator: 3x higher than non-pregnant women
The most frequently reported signs and symptoms of COVID-19–as previously noted—experienced by pregnant women were: cough, headache, muscle aches, and fever.
Racial disparities reported here mirror the CDC’s June report noting that: “Hispanic pregnant women of any race not only experienced a disproportionate risk for COVID-19 infection but also a higher risk for death compared with non-pregnant Hispanic women, and, regardless of pregnancy status, non-Hispanic Black women experienced a disproportionate number of deaths relative to their distribution among reported cases. This analysis highlights racial and ethnic disparities in both risk for infection and disease severity among pregnant women, indicating a need to address potential drivers of risk in these populations.”
Limitations to note
The limitations with this CDC data cannot be overlooked, however, and the above-cited risk stratifications should be read alongside the limitations. Most notably:
- The data collected by the CDC are voluntarily reported and rely on health care providers and public health agencies to share information regarding patients, and researchers note that there is absent uniformity in the manner by which data is collected
- Pregnancy status was missing for over one half (64.5%) of reported cases—an overwhelming majority of cases
- Of those cases who noted pregnancy status in their reporting, data on race/ethnicity was missing for 25% of cases
- Information on symptoms and underlying conditions was missing for nearly 50% of cases
- Severe case outcomes may suffer from reporting bias
Understanding risks of preterm birth and neonatal infection
In addition to Monday’s CDC report on maternal outcomes due to COVID-19, a separate analysis was published which found that pregnant women with COVID-19 are at increased risk of preterm birth. This has been reported in previous CDC studies and confirmed in multiple case reviews, both national and international. In this most recent data set, women infected with COVID-19 had a rate of preterm birth of 12.9%, compared with 10.2% in the general population.
This analysis also revealed that infant infection was infrequent (2.6%) and occurred primarily among infants whose mother had COVID-19 infection identified within 1 week of delivery.