Canadian researchers have found no increase in preterm births or stillbirths during the first year of the pandemic, alleviating concerns about the impact of the COVID-19 pandemic on pregnancy.

For our comprehensive coverage and latest updates on COVID-19 click here.

During the pandemic, the UK, Italy, India and others reported increases in stillbirths and some variability in preterm birth rates. However, most studies were small.A team led by researchers in the University of Toronto conducted a large study of more than 2.4 million births in Ontario over an 18-year period and compared trends in the pre-pandemic period (2002-2019) with the pandemic period (January to December 2020).

"We found no unusual changes in rates of preterm birth or stillbirth during the pandemic, which is reassuring," said Dr. Prakesh Shah, a paediatrician-in-chief at Sinai Health and professor at the University of Toronto. The results are published in the Canadian Medical Association Journal.

Pandemic-related measures and compliance with them could affect preterm birth rates in different settings. Thus, the researchers looked at birth outcomes in the public health units where positivity rates for SARS-CoV-2 were higher (Toronto, Peel Region, York Region and Ottawa) as well as comparing urban and rural births and those in neighbourhoods with different average income levels. "In some areas and in certain people, the restrictions could be beneficial, and in other settings or individuals, restrictions could have the opposite effect," Shah said. International studies are now underway to help understand the impact of COVID-19 on pregnancy and childbirth around the globe.

Infection, inflammation, stress, medical or pregnancy-induced disorders, genetic predisposition, and environmental factors can contribute to stillbirth and preterm birth, although in many instances the cause remains unknown.