The COVID-19 pandemic has affected Canadian women's mental health both during pregnancy and in the postpartum period, confirms the CONCEPTION study led by Anick Bérard, researcher at CHU Sainte-Justine and professor at the Faculty of Pharmacy at the Université de Montréal.

And the impact has been even greater than in other historical crises here and abroad, such as the Zika virus epidemic and the 1998 Quebec ice storm, shows the study, published in the International Journal of Environmental Research and Public Health.

The study focuses on the first three waves of the COVID-19 pandemic. According to the data collected, 23% of pregnant or postpartum women in Canada suffered from major depressive symptoms, and nearly 40% of them suffered from moderate to severe symptoms, associated primarily with anxiety and stress.

"While much attention is paid to the physical health of pregnant women, these findings prove that attention must also be paid to their mental health," said Professor Bérard. "Appropriate psychological support programs during and after childbirth need to be established."

The CONCEPTION study also showed that women who gave birth during the pandemic had more severe symptoms of depression than expectant mothers. The prevalence of symptoms increased as pregnant women approached childbirth.

"Depression, anxiety and stress in pregnant women are associated with risks of premature birth and cognitive problems during childhood," said Bérard. "To gauge the impact of these symptoms and establish strategies to reduce them, we now believe it necessary to ensure the longitudinal follow-up of children born during this period."

Of the three waves studied, the second wave between December 2020 and April 2021 was shown to have the greatest impact on the mental health of pregnant women.

More than 3,000 Canadian women, including 2,574 who were pregnant and 626 who had given birth, were recruited through social media and selected obstetrics clinics between June 2020 and August 2021.

The study used the Edinburgh Postnatal Depression Scale and the Generalized Anxiety Disorder-7 scale to analyze sociodemographic factors and mental-health measures and to compare outcomes by stage of pregnancy, gestational trimester and pandemic wave.

Pregnant participants completed an online questionnaire twice: at recruitment during pregnancy and at two-months postpartum. Women who had already given birth completed only one questionnaire.

CONCEPTION participants and their children continue to be followed to 18 months, and some children are assessed in person at 24 months. As the COVID-19 pandemic persists, recruitment for the study continues.