Perinatal Health in the United States: <scp>COVID</scp>‐19 Exacerbates an Ongoing Crisis

In the United States, over the last two decades, rates of severe maternal morbidity and adverse pregnancy outcomes have been rising, including gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy (HDP) and perinatal mood disorders. GDM increased from 4.8% to 6.4% of live births between 2011 and 2019, while the prevalence of HDP rose from 6% of delivery hospitalisations in 2000 to 12% in 2018, with a steeper rise beginning around 2013 [1, 2]. Perinatal mental health diagnoses have also shown upward trends since 2008, contributing to the growing maternal mental health burden [3]. Increasing rates of GDM and HDP have affected all racial and ethnic groups, though there are substantial and persistent racial and ethnic disparities [2]. A complex interplay of biological, behavioural, social and systemic factors drives these trends, including increasing maternal age, growing prevalence of preconception obesity and cardiometabolic disorders, increased exposure to environmental toxins and stress, and healthcare system challenges, particularly in underserved populations. Enter into this context the COVID-19 pandemic. The pandemic exacerbated economic adversity, stress and social isolation at the population level [4]. It made engaging in healthy behaviours challenging and disrupted access to health services. It deepened health inequities [4]. But how did these pandemic-related changes affect the existing maternal health crisis? In this issue of Paediatric and Perinatal Epidemiology, Karasek and colleagues [5] use sophisticated statistical approaches to examine changes in perinatal health and healthcare utilisation before and after the onset of the COVID-19 pandemic [5]. Although patterns of gestational weight gain and postpartum depression remained unchanged over this period, the authors report worrisome increases in the prevalence of gestational hypertension, GDM and prenatal depression among women giving birth in the period after the pandemic compared to the period before. Their findings further illuminate one potential pathway contributing to worsening perinatal outcomes—reductions and delays in prenatal care during the post-pandemic period. Methodologically, there are two important strengths of this research. The first is the use of an econometric Bayesian structural time-series model to estimate plausibly causal effects of the pandemic on perinatal outcomes. The model predicts a counterfactual synthetic control that would have occurred had no ‘intervention’ (e.g., the pandemic) occurred. The advantage of this model is the ability to flexibly accommodate variation in underlying trends such as seasonality, time-varying covariates, and secular trends, which are particularly important for adverse perinatal outcomes [6]. Unlike difference-in-differences, the approach does not require a set of control groups unaffected by the intervention. Such a rigorous approach is essential, as to date, the evidence on the population-level impact of the pandemic on perinatal health has been somewhat mixed [7], likely due in part to inadequate statistical modelling, among other study design differences. However, one potential limitation of this method is evidenced by a sensitivity analysis identifying strong effects using a placebo intervention, indicating that some residual confounding remained. Additionally, there were substantial changes in the demographics of births before and after the pandemic, which may indicate other unaccounted time-varying changes coinciding with the pandemic, such as fertility-related behaviours that may be correlated with outcomes. We commend the authors on their full reporting of these sensitivity analyses, which promote transparency and a more critical and nuanced understanding of their research findings. The second notable strength of this research is the use of data from the Pregnancy Risk Assessment Monitoring System (PRAMS) [8]. PRAMS is the longest-running population-based surveillance system of the US's health and well-being of pregnant persons and their infants. The data represent over 80% of US births and provide essential information on maternal behaviours, experiences, and outcomes before, during, and after pregnancy [8]. PRAMS data are widely used in perinatal research and have provided critical insights into maternal and infant health determinants and the drivers of disparities, informing state and federal policy. In the current analysis, using PRAMS allows the authors to examine unique outcomes, such as mental health symptoms, that are unavailable in administrative datasets. At the same time, PRAMS also presents some challenges, with states opting in and out of participating, resulting in a changing cohort composition over time. The authors addressed this by only including states with data available for all years in the study period. However, this means the analytical sample size was reduced, and the generalisability of their findings may be weaker. Given the importance of PRAMS for understanding trends in US perinatal health and informing perinatal health policies, ensuring the continuation of the program and strengthening it to improve state participation and participant response rates in the current era is vital. In the larger context, the declines in perinatal health observed during the pandemic take on even greater importance in public health when considered from a life course perspective. Increasingly, the perinatal period is regarded as a window into future cardiovascular health, with evidence showing that pregnant persons who experience HDP and GDM are at increased risk for future cardiovascular disease, the number one cause of death among women, as well as chronic hypertension, diabetes and dyslipidemia [9]. There are also long-term and intergenerational impacts of adverse perinatal outcomes, including mental health disorders, on child health, development and social wellbeing [10]. While much media attention has focused on the adverse impacts of the pandemic on school-aged children and adolescents, this study underscores the fact that there may also be profound, long-lasting impacts on children born during the pandemic period, not from the virus itself but from the deepening perinatal health crisis and disruptions to prenatal and postpartum health care. Understanding the population-level effects of the pandemic on women's and children's health in the long term will be an important area of future study. We can perhaps start with a better understanding of the links between stress and perinatal health—both the direct effects of acute and chronic stressors as well as their impacts on maternal health behaviours. Ultimately, these results suggest an urgent need for health systems and social policies to protect the health of US mothers before, during, and after pregnancy, during global crises, and beyond. S.R. drafted the manuscript. S.R. and E.S.B. critically reviewed and revised the manuscript, and approved the final version for publication. The authors have nothing to report. The authors declare no conflicts of interest. No data are associated with this article.