Impact of COVID-19 on pregnant women in South Korea: focusing on prevalence, severity, and clinical outcomes

Impact of perioperative COVID-19 infection on postoperative complication in cesarean section using Korean National Health insurance data

The vulnerability during pregnancy has raised concerns about the potential impact of COVID-19 on obstetric anesthesia, an essential aspect of maternal care during cesarean section procedures. To evaluate the influence of COVID-19 infection on obstetric anesthesia during cesarean section, we analyzed the data from Korean National Health Insurance System (NHIS). This retrospective study utilized data from Korean NHIS. We included patients admitted with operation codes specific to cesarean section between January 1, 2020, and December 31, 2021. We classified patients into a COVID (+) group with a diagnosis code (U071) 30 days around surgery and a COVID (-) group without the code in the same period. The primary outcome was 30-day mortality that was defined as death within 30 days of admission due to any causes. Secondary outcomes were pulmonary complications (pneumonia, acute respiratory distress syndrome [ARDS], pulmonary thromboembolism [PTE], or unexpected postoperative mechanical ventilation), ICU admission, cardiac arrest, myocardial infarction [MI], other thromboembolic events, surgical site infection, sepsis, acute renal failure [ARF], and hepatic failure. Among 75,268 patients who underwent cesarean section, 107 had a COVID-19 diagnosis code, while 75,161 did not. After 1:4 propensity score matching (PSM), 535 patients were included in each group. 30-day mortality showed no significant differences between the two groups both before and after PSM. The COVID (+) group demonstrated significantly elevated rates of pneumonia, ARDS, PTE, and surgical site infection both before and after PSM. Hospital length of stay and admission costs were also significantly longer and higher, respectively, in the COVID (+) group before and after PSM. In subgroup analysis, no differences were observed in mortality and postoperative complications based on the anesthesia method after matching. COVID-19 infection is associated with increased rates of postoperative complications, including pneumonia, ARDS, PTE, surgical site infection, longer hospital stays, and increased admission costs, in patients who underwent cesarean section.

Mediation Effect of Social Distancing on Neonatal Vitamin D Status and Related Clinical Outcomes during the Coronavirus Disease-19 Pandemic

BACKGROUND

We analyzed the impact of social distancing (SD) on vitamin D status and associated morbidity in neonates during the coronavirus disease (COVID-19) pandemic.

METHODS

Serum levels of 25-hydroxy vitamin D (25OHD) and clinical characteristics of newborn infants before (2019) and during SD (2021) were compared.

RESULTS

A total of 526 neonates (263 in 2019 and 263 in 2021) were included. The rate of vitamin D deficiency in neonates (47.1% vs. 35.4 %, p = 0.008) decreased and the rate of maternal vitamin D intake increased (6.8% vs. 37.6%, p < 0.001), respectively, during SD compared to those in 2019. The rates of hypocalcemia (12.5% vs. 3.8%, p < 0.001) and respiratory illness (57.0% vs. 43.0%, p = 0.002) decreased during SD. Neonatal vitamin D deficiency during SD was associated with maternal vitamin D supplementation (odds ratio [OR] = 0.463, p = 0.003) but was not associated with SD (OR = 0.772, p = 0.189). The mediation effect of SD on neonatal morbidity by neonatal vitamin D status was statistically insignificant.

CONCLUSIONS

SD might affect the increased maternal vitamin D intake and decreased neonatal vitamin D deficiency. However, neonatal morbidity was not affected by SD, even with neonatal vitamin D status changes.

Maternal mortality and COVID-19: A nationwide ecological analysis from Ecuador

BACKGROUND

During the COVID-19 pandemic, distinct population subsets, including pregnant women, have been differentially affected. While over 90% of COVID-19-infected pregnant women experience a benign course, a subset demonstrates marked clinical exacerbation. Symptomatic pregnant individuals, in particular, present a heightened risk of severe disease in comparison to their non-pregnant counterparts.

OBJECTIVE

The objective of this study is to systematically evaluate the epidemiological characteristics of COVID-19 in pregnant women, assess related maternal mortalities, ascertain the case fatality rate, and delineate associated risk factors.

DESIGN

This is a comprehensive population-based ecological study.

METHODOLOGY

A population-based study was conducted to investigate the epidemiological patterns of COVID-19-associated morbidity and mortality in pregnant women in Ecuador from 27 February 2020 to 14 May 2021.

RESULTS

A total of 3274 positive COVID-19 cases were identified among pregnant women, with 22 official fatalities, yielding a case fatality rate of 0.67%. The majority of cases were of Mestizo ethnicity (92.66%); however, the highest case fatality rate was noted among indigenous pregnant women (case fatality rate = 1.25%), those aged between 40 and 44 years (case fatality rate = 2.68%), and those with a history of comorbidities (2.08%). Pregnant women residing at lower altitudes (<2500 m) exhibited a higher incidence rate (0.20/100,000) compared to those at higher altitudes (>2500 m), which stood at 0.17/100,000.

CONCLUSION

The COVID-19 pandemic has profoundly impacted pregnant women in Ecuador during the first 14 months, particularly those with comorbidities, older age, and of indigenous ethnicity. These factors have heightened their vulnerability and susceptibility to severe COVID-19 infection and subsequent mortality. This underscores the urgency for comprehensive protective measures, including prioritization for vaccination. Further studies are needed to inform tailored prevention strategies and therapeutic interventions for these high-risk groups.

Analysis of pregnant women with critically severe COVID-19 in Republic of Korea from February 2020 and December 2021

OBJECTIVES

This study aimed to describe the characteristics and risk factors for severe disease in pregnant women infected with coronavirus disease 2019 (COVID-19) from the early days of the COVID-19 epidemic in Korea to the predominant period of the Delta variant.

METHODS

A retrospective cohort study was conducted among pregnant women diagnosed with COVID-19 between February 2020 and December 2021. Logistic regression analysis was performed to compare severe and mild cases after adjusting for pregnant women's age, nationality, infection route, outbreak area, infection period, symptoms, underlying disease, smoking status, trimester, and COVID-19 vaccination status.

RESULTS

In total, 2,233 pregnant women were diagnosed with COVID-19 by December 2021. Among these, 96.7% had mild symptoms, 3.3% had severe symptoms, and 0.04% died. The risk factors for severe disease in pregnant women with confirmed COVID-19 were being in the age group of 35 to 45 years, having hyperlipidemia, being in the second or third trimester of pregnancy at the time of COVID-19 diagnosis, being infected during the Delta-predominant period, and having a fever (≥38 °C) at diagnosis. Furthermore, 47.1% of patients in the mild group and 84.9% of patients in the severe group had 3 or more risk factors.

CONCLUSION

Pregnant women with COVID-19 mainly experienced mild symptoms, but those with risk factors were at a higher risk of developing severe symptoms. Therefore, treatment and follow-up management should be thoroughly implemented.

Impact of vaccination and the omicron variant on COVID-19 severity in pregnant women

We compared the clinical course of pregnant women with coronavirus disease 2019 (COVID-19) before and after the emergence of the omicron variant and based on vaccination status. We retrospectively reviewed the electronic medical charts of 224 patients and 82 deliveries from November 1, 2020, to March 7, 2022; of these, 42% were diagnosed during the omicron dominance period. Disease severity and morbidity of COVID-19 were significantly decreased during the omicron era. The vaccination rates among the patients were higher after omicron emergence (31.9%) than before (6.9%). Overall, 4.1% and 25% of patients had severe symptoms, and 2.6% and 16.2% required oxygen therapy in the vaccination and non-vaccination groups, respectively. Overall, patients had a more favorable clinical course in the omicron era; moreover, vaccinated patients were better protected than non-vaccinated patients, indicating the importance of vaccination against COVID-19.

Maternal and Neonatal Outcomes in Pregnant Women With Coronavirus Disease 2019 in Korea

BACKGROUND

This study aimed to describe the maternal, obstetrical, and neonatal outcomes in pregnant women with coronavirus disease 2019 (COVID-19) and identify the predictors associated with the severity of COVID-19.

METHODS

This multicenter observational study included consecutive pregnant women admitted because of COVID-19 confirmed using reverse transcriptase-polymerase chain reaction (RT-PCR) test at 15 hospitals in the Republic of Korea between January 2020 and December 2021.

RESULTS

A total of 257 women with COVID-19 and 62 newborns were included in this study. Most of the patients developed this disease during the third trimester. Nine patients (7.4%) developed pregnancy-related complications. All pregnant women received inpatient treatment, of whom 9 (3.5%) required intensive care, but none of them died. The gestational age at COVID-19 diagnosis (odds ratio [OR], 1.096, 95% confidence interval [CI], 1.04-1.15) and parity (OR, 1.703, 95% CI, 1.13-2.57) were identified as significant risk factors of severe diseases. Among women who delivered, 78.5% underwent cesarean section. Preterm birth (38.5%), premature rupture of membranes (7.7%), and miscarriage (4.6%) occurred, but there was no stillbirth or neonatal death. The RT-PCR test of newborns' amniotic fluid and umbilical cord blood samples was negative for severe acute respiratory syndrome coronavirus 2.

CONCLUSION

At the time of COVID-19 diagnosis, gestational age and parity of pregnant women were the risk factors of disease severity. Vertical transmission of COVID-19 was not observed, and maternal severity did not significantly affect the neonatal prognosis.

Association of triglyceride-glucose index with prognosis of COVID-19: A population-based study

Background

Triglyceride-glucose (TyG) index is a simple and reliable surrogate marker for insulin resistance. Epidemiology studies have shown that insulin resistance is a risk factor for various infectious diseases. We evaluated the prognostic value of TyG index measured before the COVID-19 infection in COVID-19 infected patients.

Methods

From a nationwide COVID-19 cohort dataset in Korea, we included COVID-19 patients diagnosed between Jan and Jun 2020. Based on the nationwide health screening data between 2015 and 2018, TyG index was calculated as ln [triglyceride (mg/dL) × fasting glucose level (mg/dL)/2]. Primary outcome is development of severe complications of COVID-19 defined as composite of mechanical ventilation, intensive care unit care, high-flow oxygen therapy, and mortality within two months after the diagnosis of COVID-19.

Results

This study included 3887 patients with COVID-19 confirmed by reverse transcription polymerase chain reaction. Mean ± standard deviation of TyG index was 8.54 ± 0.61. Severe complications of COVID-19 were noted in 289 (7.44%) patients. In the multivariate logistic regression, TyG index was positively associated with severe complications of COVID-19 (adjusted odds ratio: 1.42, 95% confidence interval [1.12–1.79]).

Conclusions

In COVID-19 infected patients, high TyG index was associated with increased risk for severe complications. TyG index might be useful predictor for the severity of COVID-19 infection.

Clinical Characteristics and Pregnancy-Related Outcomes of Pregnant Women Hospitalized with COVID-19 During the Delta Wave: A Single-Center Observational Study

Background

Coronavirus disease 2019 (COVID-19) during pregnancy is associated with increased disease severity and an increased risk of perinatal complications. However, few studies of pregnant women with COVID-19 have been conducted in Korea. The purpose of this study was to describe the clinical course and pregnancy outcomes of pregnant women admitted to our hospital with COVID-19 according to the severity.

Materials and Methods

This retrospective cohort study included women aged 18 years of age or older who were hospitalized in the Gachon University Gil Medical Center with COVID-19 during pregnancy between July 1, 2021 and January 31, 2022. COVID-19 severity was classified according to the “Criteria for severity classification by symptoms of COVID-19” presented by the Korea Disease Control and Prevention Agency. Severe cases were defined as those who required oxygen treatment administered via a high-flow nasal cannula or invasive mechanical ventilation or should be applied extracorporeal membrane oxygenation (ECMO) or continuous renal replacement therapy.

Results

A total of 103 pregnant women were hospitalized with COVID-19 during the study period. Their mean age was 33 (± 4.14) years, and 4 (3.9%) had been vaccinated against COVID-19. At the time of diagnosis of COVID-19, 3 (2.9%), 33 (32.0%), and 67 (65.1%) patients were in the first, second, and third trimester, respectively. The most common symptoms were cough (99 patients, 96.1%) and fever (85 patients, 82.5%). There was 1 (1.0%) asymptomatic patient. Forty patients (38.8%) required supplemental oxygen and 19 patients (18.4%) had severe disease. Of the 19 severe cases, 7 were in the 2nd trimester and 12 were in the 3rd trimester. Forty-one (39.8%) patients delivered, including two twin deliveries. Of the 41 cases of delivery, 14 were premature, 4 out of 21 (19.0%) in mild, 4 out of 12 (25.0%) in moderate, and 6 out of 8 (75.0%) in severe. Severe disease was associated with an increased rate of preterm birth (P = 0.012). Four of the 43 neonates (9.1%) received oxygen treatment.

Conclusion

Pregnant women with COVID-19 had a high rate of severe disease and a high preterm delivery rate, especially among those with severe disease.