COVID-19 caused an alarming rise in premature births, but vaccines have been able to counteract this, according to an American study.
The virus that causes COVID-19 puts pregnancies at risk by triggering immune and inflammatory responses and attacking the placenta. One consequence of this is premature births well before the end of the expected 39th to 40th week of pregnancy.
As the virus spread from July to November 2020, the likelihood that a mother with COVID-19 in California would give birth more than three weeks before her due date was 5.4 percentage points higher than expected – 12.3 % instead of 6.9%. A recent study came to this conclusion.
US researchers have assessed the impact of the pandemic based on the birth dates of almost 40 million California residents. They found that the increased risk of preterm birth declined slightly in early 2021 before declining sharply in 2022. Vaccines contributed to this decline, the experts explained, an effect that becomes clear when birth dates are broken down geographically.
Decline particularly in regions with good vaccination rates
“In places with zip codes with the highest vaccination rates, the additional risk of preterm birth drops much more quickly. In the summer of 2021, contracting COVID-19 during pregnancy no longer affected the risk of preterm birth in these communities. In zip codes in regions with the lowest vaccination rates, it will take almost a year longer for this to happen, said Professor Jenna Nobles of the University of Wisconsin–Madison. She and Professor Florencia Torche from Stanford University are the authors of the publication in the Proceedings of the National Academy of Sciences (PNAS). “This shows the protective effect of the COVID vaccines. An early one Vaccination increased immunity in the population and likely prevented thousands of premature births in the United States.”
Many possible negative consequences of premature birth
Prematurity is associated with a variety of short- and long-term health problems and impairments for children and their families. It increases the risk of child mortality and in many cases can require additional expensive medical care. A birth just a few weeks before the due date can have a negative impact on educational success, health and income as an adult.
“An important reason for vaccine hesitancy is that people are concerned about the safety of the fetus and the possibility of pregnancy,” says Nobles. “The results obtained here provide compelling evidence that lack of vaccination actually harms the fetus. This is a message that doctors can convey to concerned patients.”
According to the researchers, the results are likely to be a convincing argument for vaccinations and booster vaccinations, even after the COVID-related premature birth risk has decreased in California.
“This is still an evolving epidemic and the rate of booster vaccinations among pregnant women is currently very low,” Nobles added. It is a matter of time before the virus develops so that it can escape the immunity that the population currently has. “It is a miracle and incredible that we now have virtually no additional premature births, but that does not mean that this will continue in the long term.”