The meta-analysis in BMJ, or the British Medical Journal, reviewed data from 12 studies in 12 countries involving 13,136 pregnant women. The results showed that COVID-19 infection at any time during a pregnancy “increases the risk of maternal death, various maternal morbidities and neonatal morbidity, but not stillbirth or intrauterine growth retardation.”
The analysis supports what the medical community suspected during the pandemic, said Dr. Tara Denke, an obstetrician at the Mankato Clinic.
“COVID-19 infection was very harmful to pregnant women and their babies,” she said. “Not just cold symptoms, women were incredibly sick and had to be admitted to ICU. Not only did we see that in the literature, but I saw it and so did my partners here in Mankato.”
She praised the robustness of the report. It included findings from places ranging from the United States to Italy to Hong Kong to Nigeria.
Doctors look for large samples from heterogeneous populations when they analyze studies, said Dr. Tarek Khalife, regional chair of obstetrics and gynecology at Mayo Clinic Health System in Mankato. The larger the sample and the wider the range of group samples, the more general the results can be.
“The results were reassuring that we were taking COVID-19 as seriously as we thought we should,” he said.
The analysis analyzed the relative risks of various COVID-19 complications. A value of 1.5 or higher was considered an increased risk.
Compared to uninfected pregnant women, pregnant women with COVID-19 had a 23% relative risk of pneumonia and a 5.5% relative risk of developing blood clots, Khalife said.
“We’re not talking about small increases in risk,” he said. “We’re talking about significant risks.”
There are physiological reasons why a pregnant woman’s body has more difficulty coping with COVID-19. The immune system is taxed when the body works hard to grow the pregnancy, Denke said.
“The body is working overtime,” she said. “…A pregnant woman’s body changes are miraculous, but there are limits.”
Other respiratory illnesses, such as the flu, carry similar risks. When alveoli, those tiny air sacs in the lungs, fill up during an infection, the lungs sometimes compensate by using up space reserves.
Pregnant patients lose much of their reserve as the uterus pushes up toward the lungs, Khalife said.
“Just the sheer amount of reduced reserve makes them more likely to need intubation,” he said.
While the risks to pregnant women are clear, a May 2022 Kaiser Family Foundation survey found that only 42% of women who were pregnant or planning to become pregnant said they were “at least somewhat certain that the vaccine is safe”. More respondents said either “not too confident”, 31%, or “not confident at all”, 27%.
The research found that the belief in misinformation about the vaccines and pregnancy is relatively common – not just among pregnant women, but among adults in general. Massive amounts of research show that COVID-19 vaccines have been effective in limiting severe cases, hospitalizations and deaths from the disease.
Denke encouraged women to report any concerns about vaccines to their doctors.
“Your doctor wants to protect you, wants to protect your baby,” she said. “We’re always about promoting health.”
The flood of information people are exposed to online means they often see what they want to see and don’t see what they don’t want to see, Khalife said. Doctors need to find ways to keep scientific research at the forefront of their messages to patients, he added, while understanding where patients’ concerns are coming from.
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