OBJECTIVES: The purpose of this study was to assess the effectiveness of human papillomavirus (HPV) vaccination administered to adolescent girls through Korea’s National Immunization Program. METHODS: This retrospective cohort study included patients who were 12-13 years old, whether vaccinated or unvaccinated, between July 2016 and December 2017. The incidence of genital warts (GWs) was monitored through 2021. Time-stratified hazard ratios (HRs) were estimated, adjusting for birth year, socioeconomic status, and the level of urbanization of the region, and were presented with 95% confidence intervals (CIs). Data were sourced from the Immunization Registry Integration System, linked with the National Health Information Database. RESULTS: The study included 332,062 adolescent girls, with an average follow-up period of approximately 4.6 years. Except for the first year, the HRs for the vaccinated group were lower than those for the unvaccinated group. The HRs for specific cut-off years were as follows: year 2, 0.62 (95% CI, 0.31 to 1.13); year 3, 0.58 (95% CI, 0.35 to 0.96); and year 4 and beyond, 0.39 (95% CI, 0.28 to 0.52). CONCLUSIONS Our findings indicate that HPV vaccination was associated with a reduction in the risk of GWs among adolescent girls. Notably, this reduction became significant as the incidence of GWs increased with age.

Purpose: There is limited information on the clinical characteristics and prognosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy. The clinical features and risk factors for hypoxemia development were investigated in pregnant women with coronavirus disease-2019 (COVID-19). Materials and Methods: From August 2020 to February 2022, we performed a retrospective cohort study of 410 pregnant women with COVID-19. The clinical characteristics and prognoses were compared between pregnant COVID-19 patients requiring oxygen and those who did not. Results: Of 410 patients, 100 (24.4%) required oxygen therapy. Among them, fever [163 (52.6%) vs. 81 (81.0%), p<0.001] and cough [172 (56.4%) vs. 73 (73.0%), p=0.003] were more frequently observed than in non-oxygen group. The proportion of unvaccinated women was higher in oxygen group than in non-oxygen group [264 (85.2%) vs. 98 (98.0%), p=0.003]. During the Omicron wave, patients were more likely to have no oxygen requirement [98 (31.6%) vs. 18 (18.0%), p=0.009]. The risk of hypoxemic respiratory difficulty increased if SARS-CoV-2 infection occurred during the third trimester [adjusted odds ratio (aOR) 5.083, 95% confidence interval (CI): 1.095–23.593, p=0.038] and C-reactive protein (CRP) was elevated (≥1.0 mg/dL) at admission (aOR 5.878, 95% CI:3.099–11.146, p<0.001). The risk was higher in unvaccinated patients (aOR 5.376, 95% CI: 1.193-24.390, p=0.028). However, the risk was lower in patients during the Omicron wave (aOR 0.498, 95% CI: 0.258–0.961, p=0.038). Conclusion A quarter of SARS-CoV-2-infected women developed hypoxemic respiratory difficulty during pregnancy. SARSCoV-2 infection during the third trimester, CRP elevation at admission, and no vaccination increased the risk of hypoxemia in pregnant women.

Pregnancy has been shown to be associated with an adverse clinical course and symptomatic patients with severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. Extracorporeal membrane oxygenation (ECMO) is rarely used in pregnant or postpartum women with severe coronavirus disease 2019 (COVID-19). Here, we report the rare case of a pregnant woman diagnosed with SARS-CoV-2 infection placed on ECMO postpartum who subsequently received treatment for active rectal ulcer bleeding. Despite being placed on ECMO for 38 days and receiving a massive transfusion of 95 packs of red blood cells, she recovered and was discharged on hospital day 112. ECMO can be used in most patients with severe COVID-19, including pregnant patients, although potential coagulopathy complications must be considered.

Current evidence suggests that severe acute respiratory syndrome coronavirus 2 infection is associated with an increased incidence of adverse severe maternal and perinatal outcomes. However, vertical transmission is rare. The management of pregnant women with coronavirus disease 2019 (COVID-19) is similar to that of non-pregnant women, and effective treatments, including antiviral therapy, dexamethasone, and prophylactic anticoagulation should not be withheld during pregnancy.During the early COVID-19 pandemic period, the management of pregnant women was often delayed until the polymerase chain reaction (PCR) results came out or due to close contact, even among those without symptoms. Out of concern for the spread of infection, cesarean sections were performed instead of vaginal birth, since infection could have led to an increase in maternal and neonatal morbidities. Additionally, if the maternal PCR test was positive, the neonate was quarantined, and despite infectivity decreasing 10 days after symptom onset. It is necessary to ease the strict measures of infection control in the field of obstetrics.The presence or absence of maternal COVID-19 symptoms should be identified to stratify the risk, and vaginal delivery can be attempted in asymptomatic women with low infectivity. With more women being vaccinated safety data about vaccination is rapidly accumulating and no concerns have been detected. Globally, COVID-19 vaccines are recommended even during pregnancy. In order to prepare for future pandemics, it is necessary to apply lessons learned from this pandemic. Policymakers and healthcare leaders must determine efficient and effective strategies for preserving safe maternal care, even during an ongoing global emergency.

Purpose: To determine the clinical manifestations and maternal and perinatal outcomes in pregnant women with coronavirus disease 2019 (COVID-19). Methods: We conducted a retrospective observational study of pregnant women with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection who were admitted to National Health Insurance Service (NHIS) Ilsan Hospital between August 2020 and October 2021. The maternal and perinatal outcomes were investigated. Results: Among 184 pregnant women infected with SARS-CoV-2, 79 women delivered. Of the women who delivered, with 36 women giving birth during the quarantine period. At delivery, 45 women were positive for SARS-CoV-2 by polymerase chain reaction (PCR), whereas 34 women were negative. The most common clinical manifestations were cough (65.2%), fever (38.0%), and myalgia (33.2%). Regarding perinatal outcomes, none of the babies had an Apgar score <7 at 5 minutes, and none were intubated following the delivery. The preterm birth rate and small-for-gestational-age (SGA) rate were 15.2% and 16.5%, respectively. All babies who was delivered at NHIS Ilsan Hospital were negative for SARS-CoV-2 infection by PCR, which was evaluated using amniotic fluid, cord blood, neonatal nasopharyngeal and oropharyngeal swabs in the 1st and 2nd days following delivery, although 45 women were positive for SARS-CoV-2 infection by PCR at the time of delivery. Conclusion Most pregnant women with COVID-19 in South Korea were unlikely to manifest symptoms or present with a severe disease progression. The observed preterm birth rate and SGA rate were higher in women with COVID-19 than in those without COVID-19. However, there was no evidence of vertical transmission, and all babies were negative for SARS-CoV-2 infection during pregnancy.

Background: This study aimed to identify the characteristics of the referral and return of patients to clinics in the endocrinology and cardiology departments at the National Health Insurance Service Ilsan Hospital to evaluate the “referral and return of patients to clinics” program and reduce the rate of returning patients. Methods: From May 2018 to December 2020, we identified the number of visits to referral hospitals and hospital usage status at Ilsan Hospital after returning to clinics. We also identified the patients who returned to Ilsan Hospital within 6 months, defined as “failure to transport,” among those recommended to be transported to clinics of the Medical Cooperation Center. Additionally, we evaluated the characteristics of the “failure to transport” patients. Results: Among the returning patients, the rate of visiting Ilsan Hospital within 6 months was higher in cardiology than in endocrinology (25.1% vs. 16.7%). Older age, more severe disease, and more number of visits to the department were associated with a high rate of failure to transport. The rate of failure to return was low in cases diagnosed with hyperlipidemia/lipoprotein metabolism disorder. With respect to diabetes, the rate of failure to transport differed according to each type of diagnosis of diabetes. Conclusion The success rate of the “referral and return of patient to clinics” program differed based on each patient’s characteristics, department of visit, and diagnosis. Individualizing according to the visit department and diagnosis is required to ensure successful transfers, and infrastructure expansion and institutional arrangements must be facilitated.

It is unclear how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) affects pregnant women and their fetuses or newborns. We report two infants born to mothers with coronavirus disease 2019 (COVID-19) in Korea. The first case was a healthy female baby born at 39 +3 weeks' gestation from a mother diagnosed with COVID-19. The second case was a female baby born at 38 +0 weeks' gestation. The newborn in the second case had symptoms of respiratory distress immediately after birth, and nasal continuous positive airway pressure support was applied for 8 hours. Real-time polymerase chain reaction test results for SARSCoV-2 using amniotic fluid, neonatal nasopharyngeal and oropharyngeal swabs, blood, urine, stool, and rectal swab were all negative in the 1st and 2nd days of life in both cases. Placental pathology showed acute necrotizing deciduitis and intervillous fibrin deposition with acute intervillositis. Although clinical evidence of vertical transmission was not found in our cases, with the possibility of placental inflammation, close monitoring of SARS-CoV-2 positive mothers and their newborn is required.

Objective: After Women's Health Initiative (WHI) trial, hormone replacement therapy (HRT) prescription rate dropped by 16% in Korea. We investigated the relationship between the type of HRT and incidence of breast cancer (BC) in postmenopausal women in Korea.Material & Methods: We compared the prevalence of BC in 356,160 women on HRT, who reached menopause between 2004 and 2007. We divided the type and duration of HRT into three categories, i.e., estrogen-progestogen therapy (EPT), estrogen-only therapy (ET), tibolone, and 1– 3 years, 3–5 years, and ＞5 years, respectively. Results: Regarding the type of HRT among all age groups, BC risk (BCR) was lower in the tibolone group (P＜0.01). Based on age group, BCR was lower in the 50–59 years group using EPT (P=0.03) and tibolone (P＜0.01). HRT administration for ＜3 years showed a significant decrease in the tibolone group (P=0.04) and an increase in the ET group (P=0.03). In groups undergoing HRT for ＞5 years, BCR in all groups decreased (P＜0.05). Conclusions The results suggest that tibolone reduces the risk of BC in women aged ≥50 years and HRT use for ≥5 years was related to significantly decreased BCR in Korea.

Purpose: To investigate potential differences in the frequency of preterm births (PTB) between pregnancies with or without prophylactic cerclage in women with a history of conization. Materials and Methods: We identified women who had their first singleton delivery after conization between 2013 and 2018 using records in the National Health Insurance Service of Korea claims database. We only included women who had undergone a health examination and interview within 2 years before delivery. We used timing of maternal serum alpha-fetoprotein (MSAFP) tests to differentiate early (before) from late (after the MSAFP test) cerclage. The frequency of adverse pregnancy outcomes, including PTB, preterm labor and premature rupture of membranes, antibiotics and tocolytics use, cesarean delivery, and number of admissions before delivery, were compared. Results: A total of 8322 women was included. Compared to the no cerclage group (n=7147), the risks of adverse pregnancy outcomes were higher in the cerclage group (n=1175). After categorizing patients with cerclage into two groups, the risk of PTB was still higher in the early cerclage group than in the no cerclage group after adjusting for baseline factors (4.48%, 30/669 vs. 2.77%, 159/5749, odds ratio 2.42, 95% confidence interval 1.49, 3.92). Other adverse pregnancy outcomes were also more frequent in the early cerclage group than the no cerclage group. Conclusion Early cerclage performed before MSAFP testing does not prevent PTB in pregnancy with a history of conization, but increases the risk of adverse pregnancy outcomes, including PTB.

Objective: Serious bacterial infection (SBI) is a common disease among infants, and it is associated with high morbidity and mortality. Making the diagnosis of SBI is challenging and measurement of various biomarkers is useful. This study examined the utility of lactate at an emergency department for diagnosing SBI patients. Methods: This was a retrospective, observational study of febrile infants less than 90 days old presenting to the emergency department of a tertiary hospital between September 2014 and August 2017. The demographic and laboratory data was collected through a chart review. Results: Laboratory tests such as the white blood cell count, C-reactive protein (CRP), procalcitonin, and lactate showed significant differences on the Student-T test and the Mann Whitney-U test. Multivariabe logistic regression test was done using the variables with significant differences. CRP (P=0.037; odds ratio, 1.01), procalcitonin (P=0.011; odds ratio, 1.02) and lactate (P=0.001; odds ratio, 2.38) shows significant correlation. Conclusion For febrile infants at the emergency department, the measurement of lactate is expected to be a useful tool to diagnose serious bacterial infection.