As of the time of this study, in 2025, the vast majority of people on Earth have had COVID-19 at least once, if not multiple times. As studies continue to accumulate, we are seeing that a COVID-19 infection can have adverse impacts on every system and organ in the body, long after the initial acute infection (Davis et al., 2023; Arévalo-Genicio et al., 2025). There are many viruses that, when caught during pregnancy, have been associated with negative outcomes for both the pregnant person and the fetus. These include Influenza A viruses (higher mortality and increased risk of cardiovascular damage in the parent; fetal death and preterm labour for the fetus), the ZIKA virus (miscarriage, Intrauterine Growth Restriction (IUGR), preterm labour, fetal death), and HIV (preterm labour, miscarriage, IUGR), among others (Yu et al., 2022). Other studies have shown that a COVID-19 infection during pregnancy increases the risk of preeclampsia, preterm birth, and stillbirth, with severe COVID-19 infections associated with higher risks (Wei et al., 2021; McClymont et al., 2022). If there are negative pregnancy outcomes associated with a SARS-CoV-2 infection, then this should inform how our health care system treats and cares for people during pregnancy.
Currently, in Alberta, the public health messaging implies that COVID-19 is not something to be worried about, and several barriers (including financial) have been put in place against vaccination (Matthews, 2024). Only 14% of Alberta residents got a COVID-19 booster in 2024, and with increased difficulty in the booking process, and a $100 fee, it is likely that uptake will be even lower in 2025 (Lee, 2025). In Alberta, most public mask mandates were dropped in February 2022, and mandates for health care settings were removed in June 2023 (AHS, 2023; Boothby, 2022). While these actions align with the goals of "getting back to normal" and "living our lives", they may not be what is best for the long-term health of Albertans.
The scope of this study is quite narrow, focusing only on a single adverse pregnancy outcome: stillbirth. This is one of the most severe possible outcomes of a pregnancy (excluding maternal death), and often the most devastating and traumatizing for the would-be parents. Stillbirth is defined as the loss of a pregnancy after 20 weeks of pregnancy, whereas a miscarriage is the loss of a pregnancy before this threshold. There are different factors that can increase the risk of stillbirth for a given pregnancy, including (but not limited to) pre-existing health conditions (diabetes, high blood pressure, lupus, etc.), substance use, stress, and systemic barriers (e.g. racism in the health care system, lack of health insurance, etc.) (Cleveland Clinic, 2025). Some of the mechanisms that can lead to stillbirth (other than the viruses discussed above) include preeclampsia (a serious condition causing high blood pressure and organ damage), problems with the umbilical cord or placenta, cholestasis of pregnancy (liver diseases developing late in pregnancy), or a genetic defect in the baby (NHS, 2024).
This study aims to examine any patterns or correlation between COVID-19 cases and stillbirth in Alberta. We will be looking at monthly data, as this will give a more granular, detailed look at the situation than annual data. Our more specific objectives are:
Create a model that can splice together wastewater data from the two collection periods.
Create a model that could be used to examine whether periods of increased infection are associated with higher proportions of stillbirth, on a municipal basis.