Less pollution, stress linked to decrease in preterm births in early months of COVID-19 pandemic: study

Thousands fewer babies were born prematurely during the early stages of COVID-19 lockdowns, and researchers are trying to determine why.

An international study co-led by researchers at the University of Manitoba found that lockdowns during the pandemic may have prevented tens of thousands of premature births around the world – primarily in high-income countries.

“We did find a reduction, we’re pretty confident in it because we used such rigorous methodology and included so much data from around the world. And the next question is why?” said Dr. Meghan Azad, a research scientist at the Children’s Hospital Research Institute of Manitoba.

“We really wanted to get to the bottom of that, as did many people in the neonatal community around the world.

“Most good research studies answer one or two questions and then raise many more. So we’re intrigued to know why this would be.”

Azad says more than 52 million births from 26 countries between January 2015 and July 2020 were used in this research, which represents one of the first large-scale analysis of birth outcomes during the early months of the pandemic.

Their findings showed a reduction of three to four per cent in global premature births.

“When you think on a global scale that equates to potentially 50,000 births in those first few months of the pandemic that were diverted from being born prematurely, which is huge,” said Azad.

Less traffic, pollution, stress

The researchers believe the drop in premature births comes down to a reduction of inflammation, which can trigger premature childbirth. Less traffic during lockdowns meant less pollution, and working from home meant less stress.

Study contributor Dr. David Burgner says more focus on hygiene led to fewer non-COVID infection, and also believes a reduction in commuter traffic could have played a role.

“There was obviously a very dramatic reduction in air pollution during lockdown, but also individual level factors like perhaps less stress in mothers,” he said. “So there are really a lot of avenues that are ripe now for exploration.”

Neonatal specialist Dr. Michael Narvey says premature babies are at higher risk of death during their birth, and have increased risk of life-long ailments. He says any research that can reduce premature birth is paramount.

“Between eight and 10 per cent of babies are born pre-term,” said Narvey. “If you could reduce that by one or two per cent, the impact on health care, but also from the parents’ perspective, is profound.”

“They’re at risk of something called retinopathy, it’s a problem with eyesight,” added Azad. “They can also be at higher risk for chronic conditions like asthma later in life. They can have neurodevelopment issues if their brain isn’t finished developing. So there’s lot’s of immediate and long-term issues for babies born early.”

Azad says it’s too early to make recommendations to expecting mothers on how to avoid premature births, but she says this study has put them in a position to start that very research.

The “International Perinatal Outcomes in the Pandemic” study was published in the “Nature Human Behaviour” journal.