Introduction
The global coronavirus disease 2019 (COVID-19) pandemic has had a significant and widespread impact on the healthcare sector, from access to medical services to causes of death. The World Health Organization (WHO) reports that the slow progress in reducing maternal mortality started before the COVID-19 pandemic in 2020. Although the pandemic may have worsened the situation, it is not the only reason for the lack of progress [
1].
In Korea, COVID-19 spread rapidly since the first infection in January 2020 [
2]. Therefore, active interventions in health policies, such as social distancing and vaccination, were implemented throughout 2020 [
3,
4]. As a result, health statistics indicators in 2020 differed from those of the previous year. In 2020, the use of medical services decreased by 2.1% as compared to the previous year. By type of service use, the decrease was largest in the order of emergency (-19.1%), hospitalization (-10.7%), outpatient (-2.2%), and surgery (-1.3%) services. In the case of cause of death, the mortality rate by cause of death also changed around 2020 [
5].
The COVID-19 pandemic has likely altered medical care behaviors related to pregnancy and birth, and prompted stricter quarantine measures in healthcare institutions. Specifically, previous studies concluded that COVID-19 did not substantially elevate maternal mortality rates [
2]. Furthermore, several hospital-based investigations into COVID-19-related maternal deaths revealed that the mortality rate for pregnant women with COVID-19 was comparable to that of non-pregnant women of reproductive age (20-45 years). Maternal mortality rates thus remained largely unchanged from pre-pandemic levels. In addition, no evidence of vertical transmission was found in COVID-19-positive pregnant women, and the severity of COVID-19 in these women did not adversely affect neonatal outcomes [
2,
4]. South Korea’s effective response to COVID-19 and its proactive strategies for pregnant women may explain the lower prevalence of COVID-19 infection among pregnant women than among non-pregnant women. Furthermore, no COVID-19-related deaths or severe hospitalizations among pregnant women infected with the virus were reported [
4].
In this way, considering the significant impact of the pandemic on healthcare access and mortality, this study sought to analyze changes in maternal, fetal, and infant mortality rates-which are key indicators of pregnancy and childbirth health-using South Korean national statistics. Recent analyses suggested that demographic trends observed in the decades leading up to the COVID-19 pandemic, along with the reversals of those trends during the initial 2 years of the pandemic (2020-2021), can offer valuable insights into the potential long-term impacts of the pandemic [
6]. Therefore, this study aimed to update previously reported data with the latest statistics and to provide trend analysis that can support research in related fields by examining changes from before to after the implementation of social distancing and lockdown measures in 2020 [
7]. Ultimately, this research will provide a scientific basis for developing effective maternal and child healthcare policies.
Discussion
The WHO aims to reduce the global maternal mortality rate to fewer than 70 deaths per 100,000 live births by 2030, in alignment with the targets set by the sustainable development goals [
1]. The Organization for Economic Co-operation and Development (OECD) reported that the average maternal mortality ratio across its member countries was 10.9 deaths per 100,000 live births in 2020 [
8]. South Korea recorded a maternal mortality ratio of 11.8 in 2020 and of 8.4 in 2022, which aligns with the global sustainable development goals (
Fig. 1). In 2021, the average infant mortality rate in OECD countries was 4 deaths per 1,000 live births, a decrease from 4.7 deaths per 1,000 live births in 2011 [
8]. In South Korea, the infant mortality rate was 2.5 deaths per 1,000 live births in 2020, 2.4 in 2021, and 2.3 in 2022.
As the population ages, more women are having children at older ages, leading to an increase in the average age of mothers at childbirth (
Fig. 5) [
9]. The average age of pregnant women has increased by about 2 years, from 31.6 years in 2012 to 33.5 years in 2022. This reflects the rise in the proportion of mothers aged 35 years and older, which grew from 40.2% in 2012 to 52.3% in 2022.
The rapid decline in the number of births in our country is reflected in the sharp decrease in the absolute numbers of maternal, infant, and fetal deaths. However, it is important to note that the mortality indicators relative to the number of births, such as the maternal mortality ratio or the infant and fetal mortality rates, have remained at comparable levels.
A more detailed analysis revealed that maternal age is a critical determinant of mortality outcomes. For maternal mortality, the mortality ratio increased with advancing maternal age [
10], while in cases of infant and fetal mortality, the risk is significantly higher when maternal age is below 20 years [
11]. This underscores the importance of both advanced and younger maternal age as key risk factors for pregnancy-related mortality, regardless of the COVID-19 pandemic. We believe that this should be considered in the same context as the mechanisms described by the WHO regarding the impact of the COVID-19 pandemic on maternal mortality [
1,
2,
12]. The first mechanism involves deaths where a woman’s pregnancy condition interacted with COVID-19, resulting in her death, which is classified as an indirect obstetric death. The second mechanism refers to deaths caused by pregnancy complications that were not adequately prevented or managed due to disruptions in healthcare services during the pandemic. These service disruptions may have restricted access to essential maternal care, leading to an increase in preventable maternal deaths.
At the onset of the COVID-19 pandemic, the exact extent of the risks associated with pregnancy remained unclear.
The maternal mortality ratio for women aged 40 years and over increased during the COVID-19 pandemic [
13,
14]. A large-scale study found a relative risk of 1.54 for maternal morbidity and mortality, with women diagnosed with COVID-19 having a 22-fold higher risk of maternal death. Additionally, those with preexisting conditions, such as obesity, diabetes, hypertension, and chronic cardiopulmonary diseases, had a nearly four-fold increased risk of developing preeclampsia or eclampsia [
15]. We showed significant increases in severe maternal morbidity, mortality, and neonatal complications in pregnant women with COVID-19. However, caution is needed when interpreting these findings, as more research is required for a full understanding of the underlying causes of the rise in maternal mortality [
14,
16].
In this study, in 2020, the maternal mortality ratio due to postpartum complications, such as amniotic fluid embolism and other obstetric embolisms, reached 4.4 per 100,000 live births, the highest in the past decade. It then showed little variation, with 3.1 in 2012 and 3.2 in 2022.
A previous study reported a relative risk of 2.14 for severe perinatal morbidity and mortality among women with a COVID-19 diagnosis and their newborns. That study also identified at least one severe neonatal condition listed [
14].
A meta-analysis found an odds ratio of 1.71 for the occurrence of intrauterine fetal death or stillbirth in 256 women with COVID-19, as compared to 6,730 women without the virus [
17].
In the Korean data in the present study, the fetal mortality rate was 12.3 in 2012, 11.6 in 2020, and 12.2 in 2022, while the infant mortality rate was 2.9 in 2012, 2.5 in 2020, and 2.3 in 2022. These figures indicate that the rates per 1,000 live births have shown little variation.
The WHO continues to highlight that maternal mortality related to pregnancy often results from severe postpartum bleeding, usually postpartum infections, pregnancy-induced hypertension, delivery complications, and unsafe abortions, which aligns with findings from our own research [
18]. The WHO also emphasizes that these pregnancy-related causes of death can be prevented through high-quality care, stating that all women need access to excellent care during pregnancy, childbirth, and the postpartum period. Korea is considered to have an advanced healthcare system, as evidenced by its low maternal mortality rates [
19]. It would be important to examine whether it is possible to achieve even lower maternal mortality rates through further medical and policy advancements.
In conclusion, the exact extent of pregnancy-related risks remained unclear. Despite the COVID-19 pandemic, Korea experienced a sharp decrease in the absolute numbers of maternal, infant, and fetal deaths, along with a rapid decline in the number of births. However, mortality indicators relative to the number of births, such as the maternal mortality ratio and infant and fetal mortality rates, have remained at similar levels to the past.