Emily Adhikari, MD
DALLAS – April 25, 2022 – Women who were pregnant during Omicron’s recent surge were diagnosed with COVID-19 at a much higher rate than during earlier phases of the pandemic, but were less likely to develop severe illness, according to a study from UT Southwestern and Parkland Health scientists found. The investigation, reported in JAMAIt is the first published evidence documenting how the surge in COVID-19 cases late last year and early this year impacted the health of pregnant women.
“Obstetrics never stopped during the pandemic. Women are still having babies and are going for prenatal care,” said the study leader. Emily Adhikari, MD, Assistant Professor and specialist in Maternal Fetal Medicine at UTSW and Medical Director of Perinatal Infectious Diseases at Parkland Health. “It is important to understand how this virus behaves in the population we serve.”
Dr. Adhikari explained that respiratory infections, including COVID-19, are just as infectious for pregnant women as they are for the general population. However, its effects can be much more severe due to the physiological changes that occur during pregnancy: while a woman’s lung capacity decreases by 20-30% during the last pregnancy, oxygen consumption increases significantly as that the fetus grows.
Although previous research, including a study at UTSW, had shown that hospitalizations for pregnant women increased during the Delta wave of COVID-19, no research had yet quantified the severity of the Omicron variant in this population.
To this end, Dr. Adhikari, along with colleagues in Women’s and Infants Specialty Health at Parkland and in the Departments of Pathology and Pediatrics at UT Southwestern, collected data from patients who received prenatal care at Parkland Health, the county system for Dallas encompassing a centralized acute care hospital system and 10 community prenatal clinics. The researchers collected information about positive cases and whether their illness was severe, meaning the patient required supplemental oxygen or higher-level support, such as a high-flow nasal cannula, mechanical ventilation, or extracorporeal membrane oxygenation (a type of support that temporarily replaces the heart). and pulmonary function), which covers from May 17, 2020 to January 29, 2022.
Dr. Adhikari and colleagues found that 2,641 positive cases were diagnosed during this time period, which covered a pre-Delta phase, Delta surge, and Omicron surge. Their analysis showed that during the Delta surge, the case rate was three times higher than during the pre-Delta period. The case rate during the Omicron surge was 10 times higher than in the pre-Delta period. However, while the Delta cases were about three times more severe than the pre-Delta cases, the Omicron cases were about 80% less severe, Dr. Adhikari said.
He pointed out that although vaccination could have had a role in decreasing the severity of the disease, this variable was taken into account, suggesting that the differences may be due to other factors, such as the behavior of the particular SARS-CoV variant. -2 or background immunity. infection. Because the future of the pandemic remains uncertain, Dr. Adhikari added, vaccination will be key to helping pregnant women stay healthy if the next variant causes more severe disease.
“We are very lucky that although Omicron caused more cases than Delta, it was a less severe variant. If the same portion of positive patients had ended up on oxygen or ventilators, we would have been overwhelmed,” Dr. Adhikari said. “We have no control over the nature of the next variant, but pregnant women do have control over whether to receive the COVID-19 vaccine, which has been shown to help prevent serious illness and its spread.”
Other researchers who contributed to this study include Jeffrey A. SoRelle, Jessica Morse, Jessica Pruszynski, and Catherine Y. Spong, all of UT Southwestern; and Lorre MacDonald of Parkland Health.
Dr. SoRelle is the inventor of the PCR genotyping tests for variants and is entitled to income from their use.
About UT Southwestern Medical Center
UT Southwestern, one of the nation’s leading academic medical centers, integrates pioneering biomedical research with exceptional clinical care and education. The institution’s faculty has received six Nobel Prizes and includes 25 members of the National Academy of Sciences, 16 members of the National Academy of Medicine, and 14 investigators from the Howard Hughes Medical Institute. The full-time faculty of more than 2,800 is responsible for groundbreaking medical advances and is committed to rapidly translating science-driven research into new clinical treatments. UT Southwestern physicians provide care in more than 80 specialties to more than 117,000 hospital patients, more than 360,000 emergency room cases, and oversee nearly 3 million outpatient visits annually.