Premature births from cesarean (C-section) and induced deliveries dropped abruptly by 6.5% from the projected number in the first month of the COVID-19 pandemic and stayed at the lower rate consistently throughout the year, researchers have found.
Results of the study, led by Daniel Dench, PhD, assistant professor at the Georgia Institute of Technology School of Economics in Atlanta, wereonline in Pediatrics.
The authors say their findings help answer the question of whether numbers of preterm (less than 37 weeks gestation) C-sections and induced deliveries would change if women didn’t see their physicians during pregnancy as often, especially in person, and raise the question of whether some birth interventions by physicians may not be necessary. The pandemic gave researchers a natural, ethical way to study the question.
The researchers found that in March 2020 – the start of business closures and stay-at-home orders around the country – preterm births from C-sections or induced deliveries immediately fell from the forecast number for the month by 0.4 percentage points. For the rest of 2020, the number remained on average 0.35 percentage points below the numbers predicted.
That means 350 fewer preterm C-sections and induced deliveries per 100,000 live births, or 10,000 fewer overall, the authors said.
Dr. Dench told this publication the numbers for those births had been steady from January 2010 to February 2020, but the pattern “diverges from this trend very clearly beginning exactly in March 2020 and does not return to trend by December 2020.”
Meanwhile, during the study period, the number of full-term cesarean and induced deliveries stayed steady and started to increase slightly in 2020. Researchers also adjusted for seasonality as, for example, preterm births are higher on average in February than in March.
So far, Dr. Dench said in a press release, it’s not clear whether the lower numbers mean physicians didn’t deliver babies that ended up surviving in the womb anyway or if they missed some that would die in the womb without intervention.
To better understand those implications, Dr. Dench says he is turning to fetal death records for March-December 2020 and he said he expects to have those results analyzed by the end of the year.
If there was no change in fetal deaths at the same time as the drop in preterm births, Dr. Dench said, that could point to physician interventions that may not have been necessary.
Mya R. Zapata, MD, an obstetrician-gynecologist with UCLA Health, who was not involved with the study, told this publication that checking the fetal deaths is a good start and an objective outcome in answering the question, but she points out there are other outcomes that will take a deeper analysis, such as whether there are differences later in developmental outcomes after fewer physician visits.
“It’s always a good question for health care,” she said, “are we doing more than we need to?”
Dr. Zapata is the obstetrics service chief for UCLA’s labor and delivery unit and was an integral part of decision-making as to what services were essential and for which patients. She said the fewer visits and fewer ultrasounds the researchers describe fit with what ob.gyns. at UCLA experienced as the pandemic hit.
“We really tried to hone in on people who were at highest risk for an adverse outcome,” she said. “I still have the question of whether there were things we missed in low-risk people. It will take time to get the entire answer. But it does make us reflect that perhaps less intervention could be better for patients and easier. It’s our job in medicine to keep asking the question of what is essential and safe and not just continue with current practice because that’s what we’ve always done.”
The amount of data gave the researchers an unusual view. They studied 38,891,271 singleton births in the United States from 2010 to 2020 with data from the National Center for Health Statistics.
“If you look at 1,000 births in a single hospital, or even at 30,000 births across a hospital system, you wouldn’t be able to see the drop as clearly,” Dr. Dench said. “The drop we detected is a huge change, but you might miss it in a small sample.”
The researchers acknowledge a limitation of the study is that half of all preterm C-sections and induced deliveries happen because of a ruptured membrane, a spontaneous cause. Those instances can’t be distinguished from the ones caused by doctors’ interventions in this study.
“Still, these findings are significant because the causes for preterm births are not always known,” the authors wrote in the press release.
The study authors and Dr. Zapata reported no relevant financial relationships.