Indirect effect of COVID-19 on maternal mortality in Chile

Since the onset of the SARS-CoV-2 pandemic, concerns have been raised about its potential indirect negative effects on maternal and perinatal health due to the disruption of and limitations on access to health services [1]. The likely increase in maternal deaths in lowand middle-income countries (LMICs) during the pandemic is of particular concern given that women in these countries are already disproportionately burdened by complications of pregnancy and childbirth. However, only a few LMICs have published data on maternal mortality levels during the pandemic [2]. A recently published systematic review of the indirect effects of COVID 19 on pregnancy outcomes identified only four studies reporting levels of maternal mortality during the pandemic in LMICs [3]. This lack of data hinders assessment of the toll of the pandemic on maternal health and the ability of LMICs to generate appropriate response measures. To contribute to global efforts to determine the effects of COVID 19 on pregnancy outcomes, we estimated excess maternal deaths during the period of the first wave of the SARS-CoV-2 pandemic in Chile (March-December 2020). Data on maternal mortality from 1990 to 2020 were obtained from the Chilean Ministry of Health, Department of Information (DEIS) [4], upon request for research purposes under the Transparency Law (L 20.285). Maternal deaths from Covid-19 were all confirmed by the PCR test for Sars-Cov-2, and coded according to ICD10 [5]. A negative binomial model was applied to estimate excess maternal deaths by comparing the number of deaths recorded from March to December 2020 to the estimated expected levels based on the number of maternal deaths recorded during the same months in previous 30 years [6]. In 2020, maternal mortality in Chile rose to 28.1 deaths per 100,000 live births from the 19.2 level recorded in 2019, reversing the declining trend observed over the previous thirty years.

To the editor Since the onset of the SARS-CoV-2 pandemic, concerns have been raised about its potential indirect negative effects on maternal and perinatal health due to the disruption of and limitations on access to health services [1].
The likely increase in maternal deaths in low-and middle-income countries (LMICs) during the pandemic is of particular concern given that women in these countries are already disproportionately burdened by complications of pregnancy and childbirth. However, only a few LMICs have published data on maternal mortality levels during the pandemic [2].
A recently published systematic review of the indirect effects of COVID 19 on pregnancy outcomes identified only four studies reporting levels of maternal mortality during the pandemic in LMICs [3].
This lack of data hinders assessment of the toll of the pandemic on maternal health and the ability of LMICs to generate appropriate response measures.
To contribute to global efforts to determine the effects of COVID 19 on pregnancy outcomes, we estimated excess maternal deaths during the period of the first wave of the SARS-CoV-2 pandemic in Chile (March-December 2020).
Data on maternal mortality from 1990 to 2020 were obtained from the Chilean Ministry of Health, Department of Information (DEIS) [4], upon request for research purposes under the Transparency Law (L 20.285).
Maternal deaths from Covid-19 were all confirmed by the PCR test for Sars-Cov-2, and coded according to ICD-10 [5].
A negative binomial model was applied to estimate excess maternal deaths by comparing the number of deaths recorded from March to December 2020 to the estimated expected levels based on the number of maternal deaths recorded during the same months in previous 30 years [6].
In 2020, maternal mortality in Chile rose to 28.1 deaths per 100,000 live births from the 19.2 level recorded in 2019, reversing the declining trend observed over the previous thirty years. Between March 2020 (first reported case of COVID-19) and December there were 50 maternal deaths, 92% more than expected, representing 24 excess maternal deaths (95% IC 19-28 deaths) (Figure 1). The red dotted lines correspond to the confidence intervals of the expected values from the binomial model. The gray line is the monthly observed deaths.
Of the 53 maternal deaths recorded in 2020, only seven maternal deaths were directly attributed to COVID-19.
Maternal death in Chile increased by 92% in 2020 as compared with the estimated expected level during the first wave of the SARS-CoV-2 pandemic.
Only 29% (95% IC 25-37 percent) of the excess maternal deaths were attributed directly to COVID 19, indicating a considerable indirect negative effect of the pandemic on maternal health. While we observed an increase in maternal mortality between March and December 2020, we did not observe significant changes in perinatal outcomes at the same time.
These results confirm early predictions of a worsening of pregnancy outcomes due to disruption of health services during the first wave of the pandemic. In addition, they might also suggest that health systems need to be designed to be more resilient to shocks, with innovations in service delivery ready to be deployed to ensure women do not die needlessly in childbirth.

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Funding
The author(s) reported there is no funding associated with the work featured in this article.