Effect of the human papillomavirus vaccine on the risk of genital warts: a nationwide cohort study of Korean adolescent girls.

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.

Relationship between menopausal hormone therapy and incidence of fractures in postmenopausal women.

OBJECTIVE: Long-term protective effects of menopausal hormone therapy (MHT) at fractures with different doses and components are controversial. We analyzed the effect of MHT on the incidence of spine and femur fractures according to MHT type, age at commencement, duration and dose of hormones in Korean women. METHOD: This retrospective study evaluated propensity score-matched patients with MHT from the Korean National Health Insurance Service database. Among women aged ≥50 years with menopause between 2004 and 2007, spine and femur fracture incidence until 2017 was analyzed in 36,446 women who had received MHT for >1 year. Estrogen-progesterone therapy (EPT), estrogen-only therapy (ET) or tibolone therapy was conducted. RESULTS: EPT significantly lowered the incidence of spine and femur fractures with a conventional dose, but not with a low dose. Tibolone significantly decreased the incidence of spine fractures in women aged 50-59 years when used for >5 years, and the incidence of femur fractures in women older than 60 years when used for >3 years. ET significantly lowered the risk of femur fractures when estradiol was used for >5 years. CONCLUSION: In menopausal women, all MHT including conventional-dose EPT, ET and tibolone tended to lower the incidence of fractures. The effects, however, varied with the type of fracture and type of MHT.

Seasonal variations in the occurrence of preeclampsia and potential implication of upper respiratory infections in South Korea.

The aim of this study was to examine the effect of seasonal changes on the incidence of preeclampsia (PE) in South Korea and East Asian populations, and to evaluate the relationship between upper respiratory infection (URI) during pregnancy and the development of PE. This cohort study included women who had singleton births between 2012 and 2018 in South Korea. A total of 548,080 first singleton births were analyzed, and 9311 patients (1.70%) were diagnosed with PE. Multivariate analysis showed that older age (≥ 30 years old), low income, residing in the southern part of South Korea, history of cigarette smoking, heavy drinking, higher body mass index, hypertension, or diabetes mellitus were risk factors for PE. Univariate analysis showed that URI was associated with the incidence of PE (P = 0.0294). However, this association was not statistically significant in the multivariate analysis (aOR 1.01; 95% CI 0.95-1.07). After adjusting for confounding variables, the occurrence of PE was the highest in December (aOR 1.21; 95% CI 1.10-1.34) and lowest in July and August. This study demonstrated that there are seasonal variations in the occurrence of PE in South Korea. Moreover, URI may be associated with the development of PE.

Prophylactic Cerclage to Prevent Preterm Birth after Conization: A Cohort Study Using Data from the National Health Insurance Service of 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.

Evaluation of the Association between Gestational Diabetes Mellitus at First Pregnancy and Cancer within 10 Years Postpartum Using National Health Insurance Data in South Korea.

This study aims to evaluate the association between gestational diabetes mellitus (GDM) at first pregnancy and the incidence of cancer within 10 years postpartum. We used customized health information data from the National Health Insurance Corporation (NHIC). This retrospective cohort study included data from women who were not previously diagnosed with diabetes or any kind of malignancy in the National Health Screening Examination through the NHIC during 2002⁻2003, and only women who had their first delivery between 2004 and 2005 was included. Follow-up cancer diagnosis was carried out up until 2015. Among the 102,900 primiparous women, 4970 (4.83%) were diagnosed with GDM. During 10 year total follow-up period, 6569 (6.38%) cases of primary cancer were identified. The incidence of cancer was higher in women with GDM and the most common type of cancer was thyroid cancer, followed by breast cancer. On the basis of survival analysis, we adopted the Cox proportional hazards model and found that GDM was positively associated with cancer, particularly in thyroid cancer (HR: 1.27, 95% CI: 1.054⁻1.532, p = 0.012). However, the incidence of other malignancies (including ovarian and breast cancers) were not significantly associated with GDM, though they did show positive trends. Our findings suggest that GDM is associated with the incidence of cancer, particular thyroid cancer.

The Effect of Diagnosis-Related Group Payment System on Quality of Care in the Field of Obstetrics and Gynecology among Korean Tertiary Hospitals.

PURPOSE: To examine changes in clinical practice patterns following the introduction of diagnosis-related groups (DRGs) under the fee-for-service payment system in July 2013 among Korean tertiary hospitals and to evaluate its effect on the quality of hospital care. MATERIALS AND METHODS: Using the 2012-2014 administrative database from National Health Insurance Service claim data, we reviewed medical information for 160400 patients who underwent cesarean sections (C-secs), hysterectomies, or adnexectomies at 43 tertiary hospitals. We compared changes in several variables, including length of stay, spillover, readmission rate, and the number of simultaneous and emergency operations, from before to after introduction of the DRGs. RESULTS: DRGs significantly reduced the length of stay of patients undergoing C-secs, hysterectomies, and adnexectomies (8.0±6.9 vs. 6.0±2.3 days, 7.4±3.5 vs. 6.4±2.7 days, 6.3±3.6 vs. 6.2±4.0 days, respectively, all p<0.001). Readmission rates decreased after introduction of DRGs (2.13% vs. 1.19% for C-secs, 4.51% vs. 3.05% for hysterectomies, 4.77% vs. 2.65% for adnexectomies, all p<0.001). Spillover rates did not change. Simultaneous surgeries, such as colpopexy and transobturator-tape procedures, during hysterectomies decreased, while colporrhaphy during hysterectomies and adnexectomies or myomectomies during C-secs did not change. The number of emergency operations for hysterectomies and adnexectomies decreased. CONCLUSION: Implementation of DRGs in the field of obstetrics and gynecology among Korean tertiary hospitals led to reductions in the length of stay without increasing outpatient visits and readmission rates. The number of simultaneous surgeries requiring expensive operative instruments and emergency operations decreased after introduction of the DRGs.

Sonographically accessed funneling of the uterine cervix as a predictor of successful labor induction.

OBJECTIVE: The Bishop score and length of the uterine cervix are good predictors of successful labor induction. However, little is known about the association between the funneling of the uterine cervix and successful labor induction. The study aimed to evaluate cervical funneling as a predictor of successful labor induction. METHODS: This study was designed as a prospective observational study. Subjects who delivered a baby by labor induction were enrolled in the study from July 2011 to August 2013. Cervical funneling and length were examined with transvaginal ultrasonography. The Bishop score was rated by digital pelvic examination. RESULTS: A total of 163 primigravida women were recruited for the study. Of these, 137 participants (84.0%) delivered vaginally by labor induction. Cervical funneling was observed in 93 women (57.1%). Successful labor induction was significantly higher in patients with cervical funneling than those without it (91.4% vs. 74.3%, P<0.01), and was significantly associated with cervical funneling, as well as the Bishop score and cervical length. In a multivariate analysis, cervical funneling was an independent predictor for successful vaginal delivery by labor induction ( odd ratio, 2.70; 95% confidence interval, 1.02 to 7.10; P=0.04). However, the Bishop score and cervical length had no association with successful vaginal delivery. CONCLUSION: This study showed that cervical funneling could be a predictive marker for vaginal delivery during labor induction.