Maternal mortality during the COVID-19 pandemic in Mexico: a preliminary analysis during the first year

Modifications in the immune and respiratory systems in pregnancy may affect the acute respiratory distress syndrome (ARDS) from COVID-19. In addition, access and availability of family planning, reproductive health, and prenatal care services have decreased due to the response to the pandemic, particularly in low and middle-income countries [1].

Regardless of the etiology, maternal mortality is an indicator of healthcare access and availability in a particular region. Mortality in pregnant women is a preventable situation and particularly deplorable since mother and child health and wellbeing are a priority in every health system worldwide [2]. When the COVID-19 pandemic reached Mexico, health resources were largely re-oriented to address it as community transmission began. As part of the strategy, specific clinics were restricted to providing only indispensable healthcare. Public hospitals were modified (reconverted) to properly reception and treat COVID-19 patients, suspending all other conventional hospital services [3].

Like other at-risk populations, pregnant women were advised to remain at home to avoid unnecessary exposure. Despite preventive measures, an unknown number of pregnant women have probably been infected with the SARS-CoV-2 virus, and a proportion of them has developed severe clinical manifestations. A new World Health Organization (WHO) epidemiologic alert was released to encourage member countries to implement measures to ensure optimal medical attention for pregnant women and promote maternal mortality prevention awareness [4].

Mexican response for COVID-19 includes telephone-based surveillance for the epidemiologic study of cases, including sampling and testing a fraction of those cases. These measures were also recommended for pregnant women, while changes to the standards of care for reproductive health, including reducing prenatal care visits, reducing postpartum consultations, caring for minor emergencies, and reducing the number of care-focused staff complemented with remote surveillance via telephone or video call. The indication for confirmed pregnant women without alarm symptoms is to stay isolated at home for 14 days or visit a second-level hospital partially or fully reconverted to treat COVID-19 if in labor or if severe respiratory syndrome occurs [5]. Like other low-middle income countries, Mexico has not yet achieved the reductions in maternal mortality recommended by the WHO since hemorrhage and hypertensive disorders during pregnancy are still associated with maternal deaths during pregnancy, labor, or puerperium [6]. Before the pandemic, for the 2019 year, the Maternal Mortality Ratio in Mexico (including direct and indirect, excluding late deaths) was 31.2 per 100 thousand births, showing a 12.8% reduction compared to the previous year; the leading causes included obstetric hemorrhage (22.5%), hypertensive disorders (20%) and underlying respiratory diseases (15%) [7]. The need for pregnant women to have periodic clinical exams, normally in healthcare environments, is an additional aggravating factor during the COVID-19 pandemic. It means they may be more exposed to contagious individuals. As the pandemic began, the public health system increasingly used telemedicine appointments to avoid potential exposure to SARS-CoV-2. However, telemedicine poses distinct challenges when used for assessing pregnant women [8].

In Mexico, a woman’s vulnerability to maternal mortality is affected by socioeconomic factors such as education, rural residence, and indigenous ethnicity [9]. All are linked to inequities in access and availability of health resources and infrastructure, which is highly variable between different states in Mexico. Based on data as of June 2020, COVID-19 morbidity and mortality in Mexico exhibited geographical variability that may correlate to interstate sociodemographic differences in health services availability and access [3]. However, the data available to date suggest that the pandemic poses serious challenges for optimally assessing maternal health in low and middle-income countries. Mexico is no exception, and additional efforts are needed to improve [10, 11].; therefore, the objectives of the present study are

Retrospective surveillance of Maternal Mortality from February 28, 2020, to February 28, 2021, in Mexico in the 32 states was done with data from the General Office of Health Information. Board of Ethics of the Marist University of Merida (Universidad Marista de Merida - UMM) reviewed and approved the study design, exempting it from the need for ethical approval.

We have presented the MMR estimates increase during the pandemic and provided an overview of the magnitude of COVID-19 confirmed and unconfirmed maternal mortality cases. In addition, when analyzing pregnant women hospitalized due to COVID-19, we have identified particular conditions that increased vulnerability for adverse outcomes.

Of the 1056 maternal deaths recorded in Mexico in 1 year, COVID-19 was to some extent associated with 27.5% of maternal deaths that occurred. During this period, it was the leading cause of maternal death in the country. Before the advent of COVID-19, maternal mortality’s leading causes were obstetric hemorrhages and hypertensive diseases [11, 12]. This nationwide MMR was surpassed in twelve states; the most dramatic increases were observed in Guerrero, Morelos, and Chihuahua.

In the present study, the Maternal Mortality Ratio due to COVID-19 was 13.6 for confirmed and 2.4 for unconfirmed cases, while lethality among hospitalized pregnant patients was 2.8%. These results are far above the projected panorama of more than COVID-19-related maternal deaths for the United States of America [13]. A systematic review of thirteen studies from three countries (China, the United States of America, and Italy) found mortality among pregnant women with COVID-19 to be zero [14]. In other studies, maternal mortality is not assessed, for instance, in a metanalysis review of adverse pregnancy outcomes among pregnant women with COVID-19 in China and European countries [15]. The present results suggest that in Mexico, COVID-19 among pregnant women may have an unprecedented fatality rate.

Access to proper and timely care during pregnancy can dramatically affect outcomes. Intensive care unit (ICU) access is particularly vital in acute COVID-19 cases, but this can vary widely between different countries. In a study mentioned above, [14] ICU admissions of pregnant women with COVID-19 in China, the United States of America, and Italy averaged 3%. In a study of pregnant women with COVID-19 (N = 637; 1.6% mortality) hospitalized in China, ICU admission was 9.6% [16], higher than the present study’s 1.7% ICU admission rate. The second cause of maternal mortality in Mexico during the study was hypertensive diseases, proteinuria in pregnancy, puerperium (15.1%), and obstetric hemorrhage (13.8%). These disorders may be unrelated to COVID-19 infection per se. Still, the conditions prevailing in Mexico during the pandemic (e.g., long-term confinement and its immediate social correlates) may be propitious for allowing treatable adverse conditions to end in maternal mortality. This situation warrants further analysis since adequate prenatal control helps identify women with risk factors for developing obstetric hemorrhages, such as clinical diagnosis of the accrete placenta. However, the massive increase in demand for health services caused by the COVID-19 pandemic in Mexico has severely taxed the public health system’s capacity. The need for more ICU wards and additional healthcare personnel to treat the influx of COVID-19 cases resulted in the implementation of strategies such as suspension of chronic and non-urgent care in hospitals [17‐20] and giving ICU priority to COVID-19 cases.

Maternal mortality is an indicator of a country’s development level. It evidences poverty and social exclusion, and in 2015, WHO reported that 303,000 women died due to complications during pregnancy or birth, which translates to an MMR of 216 deaths per 100,000 live births. Of these deaths, 99% occurred in developing countries, and most were preventable [20].

In the current environment, this is unattainable in Mexico, which is particularly alarming compared to the 39 deaths per 100,000 live births from all causes of maternal mortality nationwide from 2005 to 2014 [21].

Maternal mortality has increased in Mexico due to COVID-19, specifically in severe cases manifesting ARDS and/or pneumonia. Complications were more probable when the cardiorespiratory system was affected. The particular vulnerability of pregnant women to SARS-CoV-2 can be explained by the probable involvement of the pathophysiological pathway involving T-helper system response and th1/th2 balance, as described for the Influenza A virus [22]. Individual lifestyle may also have some effect on case severity. The way to address this threat is for maternal health care professionals to closely monitor patients with COVID-19. Their clinical manifestations need to be controlled using a preventive approach focusing on those with underlying chronic conditions, which documents signs and symptoms of severity as a way of deciding if and when ambulatory or in-hospital treatment is indicated. Procedures need to be developed based on available resources and existing guidelines, and patients need to be aware of them [23, 24].

As shown in the present results, not all maternal deaths in Mexico are directly related to COVID-19 infection but rather to uncontrolled conditions during pregnancy due to the limited healthcare availability. Social distancing and limited mobility are crucial to reducing SARS-CoV-2 transmission. Nonetheless, healthcare during pregnancy is also essential to ensure healthy pregnancies. In-person medical attention can be reinforced during this pandemic by telemedicine or web-based strategies to monitor and detect any pregnancy or COVID-19 related complication and guide decision-making, including suitable transportation to specialized health centers [25].

Unintended pregnancies are commonly associated with late or no prenatal care in Mexico [26], and these pregnancies may be more frequent at both extremes of the reproductive age span (< 18 or > 38 years). During the pandemic, unintended pregnancies can be complicated by confinement and consequent delays in or omission of early medical attention. A recent estimate is that 145,719 births in Mexico in 2020 were from unintended pregnancies, mainly in response to the social behaviors derived from confinement and the barriers to adequate healthcare and family planning created by the pandemic [27]. For instance, the Pan-American Health Organization (PAHO) recently called on member states to intensify and improve access to prenatal care services and preventive measures to reduce COVID-19 morbidity and mortality. Furthermore, the PAHO asked its members to renew their commitment to reducing maternal and perinatal mortality even more than pre-pandemic [4], implying an urgent need for preventive strategies at all levels.

The MMR in Mexico increased over 60% in 1 year during the pandemic; COVID-19 was linked to 25.4% maternal deaths in the studied period. Lethality among pregnant women with a diagnosis of COVID-19 was 2.8%, and while asthma and immune impairment increased propensity for developing pneumonia, obesity and diabetes increased the odds for in-hospital death. Measures are needed to improve access to coordinated well-organized healthcare to reduce maternal deaths related to COVID-19 and pandemic collateral effects. The results highlight the need for timely, organized, and efficient maternal and obstetric healthcare at all times, but particularly during a pandemic. Providing pregnant women access to the necessary healthcare resources in the community and clinical settings must be considered a priority.