A new survey of more than 4,000 pregnant women hospitalized in the United Kingdom with COVID-19 during the first 18 months of the pandemic shows severe illness was linked to poor birth outcomes, including pre-labor caesarean birth, very or extreme preterm birth, stillborn birth, and the need for admission to a neonatal unit.
A smaller study in the United Arab Emirates (UAE) reported a similar impact.
Higher impact on women with risk factors
In the UK study, women who were 30 or older, obese, mixed ethnicity, or diagnosed with gestational diabetes were more likely to suffer from an increased risk of poor pregnancy outcomes.
The research was published today in Acta Obstetricia et Gynecologica Scandinavica, and its authors say it further supports the need to vaccinate pregnant women against COVID-19, especially those who have co-morbidities that make either pregnancy or COVID-19 infection more risky.
"This study emphasizes the importance of ensuring that interventions to promote vaccine uptake are particularly focused towards those at highest risk," said senior study author Marian Knight, FMedSci, of the University of Oxford, in a press release from Wiley, the journal's publisher.
14% of pregnant women had severe infection
The study included hospital admissions across the United Kingdom from Jan 3, 2020 to Oct 31, 2021. Though the study included 4,436pregnant women who were hospitalized for COVID-19, severe infection — defined as need for high flow or invasive ventilation, intensive care unit (ICU) admission, or death — was described in 13.9% of women, or 616. Two-thirds (65.4%) of women had mild infection, and 20.7% had moderate infection.
Women with severe infection were more likely to be 30 or older (adjusted odds ratio [aOR], 1.48; 95% confidence interval [CI], 1.20 to 1.83), be overweight or obese (aOR, 1.73; 95% CI, 1.34 to 2.24 and aOR, 2.52; 95% CI, 1.97 to 3.23, respectively), be of mixed ethnicity (aOR, 1.93; 95% CI, 1.17 to 3.21), or have gestational diabetes (aOR, 1.43; 95% CI, 1.09 to 1.87.).
Women with severe COVID-19 in pregnancy were 2.6-fold more likely to be 40 years or older, compared with those with mild or moderate infection.
Those with severe disease were much more likely to experience pre-labor cesarean birth (aOR, 8.84; 95% CI, 6.61 to 11.83), a very or extreme preterm birth (<32 weeks’ gestation, aOR, 10.75; 95% CI, 7.78 to 14.85; <28 weeks' gestation, aOR, 12.35; 95% CI, 6.34 to 24.05) and their babies were more likely to be stillborn (aOR, 2.51; 95% CI, 1.35 to 4.66) or admitted to a neonatal unit (NNU) (aOR, 11.61; 95% CI, 9.28 to 14.52).
Of the 112 women with severe COVID-19 who were hospitalized and then discharged while still pregnant, 85.7% gave birth at or after full term (37 weeks), though 3 women suffered stillbirths.
Though stillbirths and neonatal deaths (10 recorded in the study) were rare, the authors said, "Babies born to mothers with severe infection were 12-fold more likely to be admitted to the NNU compared with those born to mothers with mild to moderate infection."
"A very high proportion of women with severe COVID-19 have a cesarean birth, with their babies born preterm and admitted to the NNU," they wrote. "Prevention of COVID-19 is therefore key."
UAE study shows high need for NICU care
The smaller UAE study echoes the findings seen in the United Kingdom. That research, published yesterday in Scientific Reports, tracked outcomes of 200 pregnant women with COVID-19, 53 of whom presented with moderate to severe disease.
Those 53 women had a higher incidence of preterm delivery and low birth weight. Of their babies, 58.5% were born with COVID-19, and 95% were admitted to the neonatal ICU (NICU).
The study also showed an increased risk of poor outcomes, even among women with mild to moderate disease.
"The present study showed 35.0% preterm births and 30.5% low birth weight among pregnancies with COVID-19 regardless the severity of the disease," the authors wrote.
