Pregnant women with COVID-19 have higher risk for preterm birth

Women diagnosed with COVID-19 while pregnant, particularly those with other comorbidities, had a higher risk for very preterm birth, preterm birth and early-term birth, a population-based study showed.

The study in The Lancet Regional Health – Americas is the first of its kind large enough to identify the risks for COVID-19 by specific subtype of preterm birth, as well as by race, ethnicity and insurance status, according to a press release.

Deborah Karasek, PhD, an assistant professor in the department of obstetrics, gynecology and reproductive sciences at the University of California, San Francisco, and colleagues analyzed data on 204,157 live births in California between July 2020 and January 2021. Among the mothers, 8,957 had a COVID-19 diagnosis during pregnancy.

The researchers wrote that they used “best obstetric estimate of gestational age” to label the births as either very preterm (fewer than 32 weeks), preterm (fewer than 37 weeks), early term (between 37 and 38 weeks) or term (between 39 and 44 weeks).

They noted that there was a “disproportionate burden” of COVID-19 infection in underrepresented groups. For example, among women who gave birth in January, 12.9% of American Indian/Alaska Native women, 11.4% of Native Hawaiian/Pacific Islander women, 10.3% of “Latinx” women and 5.7% of non-Latinx Black women had a COVID-19 diagnosis during pregnancy compared with 4.6% of non-Latinx white women and 3.8% of Asian women. “Latinx” is a gender-neutral alternative to Latino or Latina.

Karasek and colleagues reported that a COVID-19 diagnosis was linked to an increased risk for very preterm birth (adjusted RR = 1.6; 95% CI, 1.4-1.9), preterm birth (aRR = 1.4; 95% CI, 1.3-1.4) and early-term birth (aRR = 1.1; 95% CI, 1.1-1.2). The overall risk remained the same regardless of race/ethnicity or insurance status. However, women with a COVID-19 diagnosis and hypertension, diabetes or obesity had a 100% higher risk for preterm birth and 160% higher risk for very preterm birth compared with women without a COVID-19 diagnosis or comorbidities, according to the release.

“Given that the burden of COVID-19 is greater in these populations, as is the burden of pre-term birth, it really points to the need for an equity approach,” Karasek said in the press release. “With the surge in infections and increase in the Delta variant, we must think about pregnant people, especially Black and Brown populations, as the groups that need to be prioritized, with supportive policies to reduce exposure and stress, and increase access to care.”

The study findings also underscore the importance of vaccination in pregnant women, Karasek said.

Both the American College of Obstetricians and Gynecologists and the CDC recommend that pregnant women receive the COVID-19 vaccine. Recently, the CDC reinforced its recommendation, citing data from an analysis of nearly 2,500 pregnant women that showed the COVID-19 mRNA vaccine before 20 weeks of pregnancy did not increase the risk for miscarriage. Despite this, according to the agency, only about 23% of pregnant women in the U.S. have received at least one dose of a COVID-19 vaccine.

Karasek recommended that health care professionals and pregnant women have two-way discussions regarding COVID-19 vaccination.

“Pregnant people may have concerns about vaccines and the health of their baby, so being able to have an open dialogue that values those concerns, describes evidence about safety, and conveys the risks posed by COVID-19 infection during pregnancy is critically important,” she said in the press release.

References:

American College of Obstetricians and Gynecologists. COVID-19 vaccination considerations for obstetric–gynecologic Care. https://www.acog.org/clinical/clinical-guidance/practice-advisory/articles/2020/12/covid-19-vaccination-considerations-for-obstetric-gynecologic-care. Accessed Aug. 12, 2021.

CDC. COVID-19 data tracker. https://covid.cdc.gov/covid-data-tracker/#vaccinations-pregnant-women. Accessed Aug. 13, 2021.

Fernandez, E. COVID-19 during pregnancy associated with preterm birth. https://www.ucsf.edu/news/2021/08/421181/covid-19-during-pregnancy-associated-preterm-birth. Accessed Aug. 12, 2021.

Karasek D, et al. Lancet Regional Health-Americas. 2021;doi.org/10.1016/j.lana.2021.100027.