The impact of the COVID-19 pandemic on infant obesity: A nationwide retrospective cohort study.

BACKGROUND: Lifestyle changes, such as those related to the COVID-19 pandemic, including alterations in physical activity and dietary habits, are known to affect pregnancy outcomes. In particular, suboptimal intrauterine conditions during pregnancy are known to influence not only fetal growth but also growth during infancy. However, research on the impact of the environmental changes caused by the COVID-19 pandemic on the growth of infants and children during their early years is lacking. To address this issue, this study evaluated the effect of the COVID-19 pandemic on obesity in infants. METHODS: This retrospective cohort study used the data collected from the Korea National Health Insurance (KNHI) claims database. The data of 1985,678 women who delivered infants between 2015 and 2021 were collected. Women who delivered during the pandemic and those who delivered during the pre-pandemic period were matched in a 1:1 frequency-matched pair procedure for factors such as age, hypertension, diabetes mellitus, preeclampsia, gestational diabetes mellitus, mode of delivery, gestational age at delivery, offspring sex, and birth weight. Finally, 197,580 women were enrolled. The weight and head circumference of infants (4-6 months of age) of the COVID-19 pandemic group were compared with those of the pre-pandemic group. RESULTS: The COVID-19 pandemic group infants exhibited significantly higher weight and prevalence of obesity at 4-6 months of age compared to infants in the pre-pandemic group. After adjustment for covariates, pandemic group infants had a higher risk of obesity (odds ratio: 1.54, 95% confidence interval: 1.51-1.57) compared to the pre-pandemic group infants. CONCLUSION: The COVID-19 pandemic has had a notable impact on the weight of infants aged 4-6 months. This suggests that pandemic conditions may influence the growth of newborns, underscoring the importance of monitoring and assessing trends in the growth of infants born during such crises.

Adverse pregnancy outcomes as a risk factor for new-onset metabolic dysfunction-associated steatotic liver disease in postpartum women: A nationwide study.

Background & Aims: Adverse pregnancy outcomes (APOs) can worsen cardiometabolic risk factors in women, raising their likelihood of developing cardiometabolic diseases at a young age after their initial pregnancy. Nevertheless, there are limited data on the risk of newly developing metabolic dysfunction-associated steatotic liver disease (MASLD) in women who have had APOs. This study aimed to evaluate the risk of new-onset MASLD after experiencing APOs. Methods: Singleton pregnant women who underwent national health screenings 1 year before pregnancy and 1 year after delivery were included in this study. APOs were defined as the presence of at least one of the followings: hypertensive disorders of pregnancy (HDP), gestational diabetes mellitus (GDM), preterm birth, low birth weight, and placental abruption. The primary outcome was new-onset MASLD based on the presence of APOs. Results: Among 80,037 study participants, 9,320 (11.6%) experienced APOs during pregnancy. Women who experienced APOs had an increased risk of developing new-onset MASLD after delivery even after adjustments for various covariates (adjusted odds ratio [OR] 1.58, 95% CI 1.45-1.72). In particular, women who experienced either HDP or GDM showed a significantly increased risk of developing new-onset MASLD (adjusted OR 2.20, 95% CI 1.81-2.67, for HDP and adjusted OR 1.83, 95% CI 1.65-2.03, for GDM). Moreover, there was a tendency toward an increased risk of new-onset MASLD according to the number of APOs (p <0.001 for trend of odds). Conclusions: APOs were associated with the risk of new-onset MASLD after delivery. Specifically, only HDP or GDM were identified as risk factors for new-onset MASLD. Impact and implications: This nationwide cohort study confirms that postpartum women with a history of adverse pregnancy outcomes (APOs) are at an increased risk of developing metabolic dysfunction-associated steatotic liver disease (MASLD). These findings may bring us one step closer to understanding the exact mechanisms underlying such an important association between prior APOs and cardiovascular disease (CVD) risk among postpartum women. This bidirectional association between APOs and MASLD highlights the importance of considering pregnancy history in assessing CVD risk in women. It suggests a need for closer monitoring and lifestyle interventions for women with a history of APOs to reduce the risk of MASLD and subsequent CVD complications.

The timing of adenomyosis diagnosis and its impact on pregnancy outcomes: a national population-based study.

OBJECTIVE: Adenomyosis impacts pregnancy outcomes, although there is a lack of consensus regarding the actual effects. It is likely, however, that the severity of adenomyosis or ultrasound findings or timing of diagnosis can have different effects on adverse pregnancy outcomes (APOs). METHODS: In this study, we aimed to investigate the impact of the timing of adenomyosis diagnosis on pregnancy outcomes. Singleton pregnant women who delivered between 2017 and 2022 were analyzed based on the timing of adenomyosis diagnosis, using a national database. The final cohort was classified into three groups: 1) group 1, without adenomyosis; 2) group 2, those diagnosed with adenomyosis before pregnancy; and 3) group 3, those diagnosed with adenomyosis during pregnancy. RESULTS: A total of 1,226,475 cases were ultimately included in this study. Women with a diagnosis of adenomyosis had a significantly higher risk of APOs including hypertensive disorder during pregnancy (HDP), gestational diabetes mellitus (GDM), postpartum hemorrhage, placental abruption, preterm birth, and delivery of a small-for-gestational-age infant even after adjusting for covariates. In particular, concerning HDP, the risk was highest in group 3 (group 2: adjusted odds ratio [aOR], 1.15 vs. group 3: aOR, 1.36). However, the highest GDM risk was in group 2 (GDM; group 2: aOR, 1.24 vs. group 3: aOR, 1.04). CONCLUSION: The increased risk of APO differed depending on the timing of adenomyosis diagnosis. Therefore, efforts for more careful monitoring and prevention of APOs may be necessary when such women become pregnant.

The Risk of Hypertension and Diabetes Mellitus According to Offspring's Birthweight in Women With Normal Body Mass Index: A Nationwide Population-Based Study.

BACKGROUND: Maladaptation to vascular, metabolic, and physiological changes during pregnancy can lead to fetal growth disorders. Moreover, adverse outcomes during pregnancy can further increase the risk of cardiovascular and metabolic diseases in mothers. Delivering a large-for-gestational-age (LGA) baby may indicate a pre-existing metabolic dysfunction, whereas delivering a small-for-gestational-age (SGA) baby may indicate a pre-existing vascular dysfunction. This study aims to assess the risk of hypertension (HTN) and diabetes mellitus (DM) in women with normal body mass index (BMI) scores who did not experience gestational DM or hypertensive disorders during pregnancy based on the offspring's birthweight. METHODS: This retrospective nationwide study included women with normal BMI scores who delivered a singleton baby after 37 weeks. Women with a history of DM or HTN before pregnancy and those with gestational DM or hypertensive disorders, were excluded from the study. We compared the risk of future maternal outcomes (HTN and DM) according to the offspring's birthweight. Multivariate analyses were performed to estimate the hazard ratio (HR) for the future risk of HTN or DM. RESULTS: A total of 64,037 women were included in the analysis. Of these, women who delivered very LGA babies (birthweight > 97th percentile) were at a higher risk of developing DM than those who delivered appropriate-for-gestational-age (AGA) babies (adjusted HR = 1.358 [1.068-1.727]), and women who delivered very SGA babies (birthweight < 3rd percentile) were at a higher risk of developing HTN than those who delivered AGA babies (adjusted HR = 1.431 [1.181-1.734]), even after adjusting for age, parity, gestational age at delivery, fetal sex, maternal BMI score, and a history of smoking. CONCLUSION: These findings provide a novel support for the use of the offspring's birthweight as a predictor of future maternal diseases such as HTN and DM.

Short-term neonatal and long-term neurodevelopmental outcome of children born term low birth weight.

This study aimed to examine the impact of term LBW on short-term neonatal and long-term neurodevelopmental outcomes in children 5-7 years of age. This is a population-based cohort study that merged national data from the Korea National Health Insurance claims and National Health Screening Program for Infants and Children. The participants were women who gave birth at a gestational age of ≥ 37 weeks between 2013 and 2015 in the Republic of Korea, and were tracked during 2020 for the neurodevelopmental surveillance of their children. Among 830,806 women who gave birth during the study period, 31,700 (3.8%) of their babies weighed less than 2500 g. By Cox proportional hazard analysis, children aged 5-7 years who had LBW were associated with any developmental, motor developmental delay, cognitive developmental delay, autism spectrum, attention deficit hyperactivity disorders, and epileptic and febrile seizures.Children born with term LBW were more vulnerable to neurodevelopmental disorders at 5-7 years of age than those with normal and large birth weights. This study further substantiates counseling parents regarding the long-term outcomes of children being born underweight.

The Role of the Aryl Hydrocarbon Receptor in Vascular Factors Related to Preeclampsia in a Smoking Mouse Model.

Smoking cigarettes is known to lower the risk of preeclampsia. The objective of this study is to evaluate the effect of smoking on the expression of soluble FMS-like tyrosine kinase-1 (sFlt-1), vascular endothelial growth factor (VEGF), and endoglin (sEng)-1 and the role of the aryl hydrocarbon receptor (AhR) in pregnant mice. We developed a smoking mouse model using a gas-filling system. One or two cigarettes per day were exposed to each of the five pregnant mice for five days a week throughout pregnancy. AhR agonist and antagonist were injected. Serum levels and expression in the placenta of sFlt-1, VEGF, and sEng-1 were analyzed and compared among the cigarette smoke and no-exposure groups after delivery. Compared to the no-smoke exposure group, the serum level of sFlt-1 was significantly decreased in the two-cigarette-exposed group (p < 0.001). When the AhR antagonist was added to the two-cigarette-exposed group, sFlt-1 levels were significantly increased compared to the two-cigarette group (p = 0.002). The levels of sFlt-1 in the AhR antagonist group did not change regardless of two-cigarette exposure (p = 0.064). With the AhR agonist, sFlt-1 decreased significantly compared to the control (p = 0.001) and AhR antagonist group (p = 0.002). The sFlt-1 level was significantly decreased after the injection of the AhR agonist compared to the control group (p = 0.001). Serum levels of VEGF were significantly decreased in the one-cigarette-exposed group compared to the control group; however, there was no difference between the control and the two-cigarette-exposed groups. The placental expression of sFlt-1, VEGF, and sEng were inconsistent. This study offers insights into the potential role of AhR on antiangiogenic sFlt-1 associated with preeclampsia. It may support the invention of a new treatment strategy for preeclampsia using AhR activation.

Headaches during pregnancy and the risk of subsequent stroke.

BACKGROUND: Primary headache disorder is a known risk factor for stroke in women and usually improves during the first trimester of pregnancy. However, despite this, some women develop headaches during pregnancy (G-HA), and the effect of this headache on subsequent stroke is unknown. In this study, we evaluated the association between G-HA and stroke after delivery in women. METHODS: Based on the Korean National Health Insurance Service database, we included women hospitalized for delivery between 2012 and 2013. G-HA was defined as a headache diagnosed during pregnancy. Primary outcome was any stroke that occurred during the observational periods from delivery to December 31, 2020. All diseases were identified based on data registered in the database using the International Classification of Disease-10th Revision-Clinical Modification codes. RESULTS: Of 906,187 pregnant women, G-HA was found in 56,813 (6.3%). During the observational periods, the G-HA ( +) group had a significantly higher risk of any stroke [adjusted hazard ratio (aHR) = 1.59, 95% confidence interval (CI): 1.30-1.95], ischemic stroke (aHR = 1.50, 95% CI: 1.12-2.01), hemorrhagic stroke (aHR = 1.63, 95% CI: 1.23-2.15), and intracerebral hemorrhage (aHR = 1.63, 95% CI: 1.19-2.23) than the G-HA (-) group. When analyzed considering the interaction with history of headache disorder, G-HA showed a significant association with hemorrhagic stroke, but lost its effect on ischemic stroke. CONCLUSIONS: We demonstrated that G-HA was associated with subsequent stroke occurrence after delivery. However, the relationship between G-HA and ischemic stroke is mitigated by a history of pre-pregnancy headache disorder.

Association of maternal thyroid disease with obesity in child.

OBJECTIVES: During pregnancy, many women develop thyroid disorders, which can result in fetal and neonatal development defects. We investigated whether maternal thyroid dysfunction would affect their children's growth and obesity. STUDY DESIGN: We conducted a nationwide population-based cohort study using a combination of data from several Korean nationwide registries to investigate the association between maternal thyroid dysfunction, offspring growth, and obesity. Childhood growth was repeatedly measured at three periods of age from 42 to 80 months, using body mass index (BMI). RESULTS: A total of 1,123,499 women were enrolled in this study; 78,902 (7.0 %) had pre-pregnancy thyroid disease. Significant association was found between maternal hyperthyroidism and obesity in all children aged 42-66 months (42-54 months, adjusted odds ratio (aOR) 0.93, 95 % confidence interval (CI) 0.89-0.98; 54-66 months, aOR 0.93, 95 % CI 0.87-0.99), but not at later ages. In the analysis by sex, maternal hyperthyroidism was associated with childhood obesity in boys, whereas it was not associated with those in girls of any age. No association was observed between maternal hypothyroidism and child BMI or obesity. CONCLUSIONS: The association between maternal thyroid function and obesity in offspring is attenuated from early to late childhood, suggesting that many other factors may be involved in developing childhood obesity.

Personal exposure of PM2.5 and metabolic syndrome markers of pregnant women in South Korea: APPO study.

We examined the association between exposure to PM2.5, focused on individual exposure level, and metabolic dysfunction during pregnancy. APPO study (Air Pollution on Pregnancy Outcome) was a prospective, multicenter, observational cohort study conducted from January 2021 to March 2023. Individual PM2.5 concentrations were calculated using a time-weighted average model. Metabolic dysfunction during pregnancy was assessed based on a modified definition of metabolic syndrome and its components, accounting for pregnancy-specific criteria. Exposure to PM2.5 during pregnancy was associated with worsened metabolic parameters especially glucose metabolism. In comparison to participants exposed to the low PM2.5 group, those exposed to high PM2.5 levels exhibited increased odds of gestational diabetes mellitus (GDM) after adjusting for confounding variables in different adjusted models. Specifically, in model 1, the adjusted odds ratio (aOR) was 3.117 with a 95% confidence interval (CI) of 1.234-7.870; in model 2, the aOR was 3.855 with a 95% CI of 1.255-11.844; in model 3, the aOR was 3.404 with a 95% CI of 1.206-9.607; and in model 4, the aOR was 2.741 with a 95% CI of 0.712-10.547. Exposure to higher levels of PM2.5 during pregnancy was associated with a tendency to worsen metabolic dysfunction markers specifically in glucose homeostasis. Further research is needed to investigate the mechanisms underlying the effects of ambient PM2.5 on metabolic dysfunction during pregnancy.

Prepregnancy Glucose Levels Within Normal Range and Its Impact on Obstetric Complications in Subsequent Pregnancy: A Population Cohort Study.

BACKGROUND: We sought to identify the influence of prepregnancy glucose levels on obstetric complications in subsequent pregnancy. METHODS: Women in Republic of Korea who had given birth between January 1st, 2007 and December 31st, 2010 were enrolled. The database of the Health Insurance Review and Assessment Service and data from a national health screening program for infants and children were used. Subjects were divided into seven groups according to their fasting glucose levels. RESULTS: 59,619 women were included for analysis, and 10.4%, 13.7%, 19.1%, 21.5%, 16.0%, 11.6%, and 7.5% women had glucose levels of < 75, 75-79, 80-84, 85-89, 90-94, 95-100 and > 100 mg/dL. Each 5 mg/dL increase in prepregnancy fasting glucose levels was associated with increased risk of gestational diabetes and macrosomia in subsequent pregnancy. Adjusted risk ratio for gestational diabetes per standard deviation prepregnancy glucose > 100 mg/dL was 2.015 (95% confidence interval, 1.649-2.462) and for macrosomia an adjusted risk ratio 1.389 (95% confidence interval, 1.147-1.682). CONCLUSION: Higher prepregnancy glucose level within normal range was related to gestational diabetes and macrosomia in following pregnancy. Our results may aid in the identification of women at future risk of obstetric complications and may guide to stratify women into normal and intensified care. TWEETABLE ABSTRACT: Higher prepregnancy glucose in normal range is associated with gestational diabetes and macrosomia.

Increased risk of congenital malformations in offspring born to women with systemic lupus erythematosus in South Korea: a nationwide population-based study.

OBJECTIVES: The aim of this study was to determine the risk of congenital malformations in offspring born to women with systemic lupus erythematosus (SLE). METHODS: This nationwide population-based study included Korean women who had a singleton pregnancy. The risk of congenital malformations in women with SLE was compared with those without SLE. Multivariable analyses were performed to estimate the OR of congenital malformations. In a sensitivity analysis, the risk of malformation was compared between the offspring of women with SLE and those of propensity-matched women without SLE. RESULTS: Of a total of 3 279 204 pregnant women, 0.1% had SLE and their offspring had a higher frequency of congenital malformations (17.13% vs 11.99%, p<0.0001). After adjustment for age, parity, hypertension, diabetes, and fetal sex, the SLE group was found to be associated with an increased risk of congenital malformations in the nervous system (adjusted OR (aOR, 1.90; 95% CI, 1.20 to 3.03), eye, ear, face, and neck (aOR, 1.37; 95% CI, 1.09 to 1.71), circulatory system (aOR, 1.91; 95% CI, 1.67 to 2.20), and musculoskeletal system (aOR, 1.26; 95% CI, 1.05 to 1.52). Even after propensity matching, some of the tendencies were maintained. CONCLUSIONS: This nationwide population-based study in South Korea indicates that compared with the general population, neonates born to SLE mothers have a slightly increased risk of congenital malformations affecting the nervous system, head and neck, cardiovascular system, and musculoskeletal system. When a woman with lupus becomes pregnant, careful fetal ultrasound and newborn screening can be helpful in identifying the risk of potential malformations.

Investigating the regenerative effects of folic acid on human amniotic epithelial stem cells and amniotic pore culture technique (APCT) model in vitro using an integrated pharmacological-bioinformatic approach.

INTRODUCTION: Disruption of fetal membranes before the onset of labor is referred to as premature rupture of membranes (PROM). Lack of maternal folic acid (FA) supplementation reportedly leads to PROM. However, there is a lack of information on the location of FA receptors in the amniotic tissue. Additionally, the regulatory role and potential molecular targets of FA in PROM in vitro have rarely been investigated. METHODS: The three FA receptors (folate receptor α isoform [FRα], transporter of reduced folate [RFC], and proton-coupled folate transporter [PCFT]) in human amniotic epithelial stem cells (hAESCs) and amniotic tissue were localized using immunohistochemistry and immunocytochemistry staining. Effect and mechanism analyses of FA were performed in hAESCs and amniotic pore culture technique (APCT) models. An integrated pharmacological-bioinformatics approach was utilized to explore the potential targets of FA for the treatment of PROM. RESULTS: The three FA receptors were widely expressed in human amniotic tissue, especially in the hAESC cytoplasm. FA stimulated the amnion regeneration in the in vitro APCT model. This mimics the PROM status, in which cystathionine-ß-synthase, an FA metabolite enzyme, may play an important role. The top ten hub targets (STAT1, mTOR, PIK3R1, PTPN11, PDGFRB, ABL1, CXCR4, NFKB1, HDAC1, and HDAC2) of FA for preventing PROM were identified using an integrated pharmacological-bioinformatic approach. DISCUSSION: FRα, RFC, and PCFT are widely expressed in human amniotic tissue and hAESCs. FA aids the healing of ruptured membrane.

Risk of retinopathy in women with pregnancy-induced hypertension: a nationwide population-based cohort study of 9-year follow-up after delivery.

BACKGROUND: The retina is potentially associated with several physiological, hormonal, and metabolic changes during pregnancy. The few available epidemiologic studies of ocular changes in pregnancy have mainly concerned retinopathies. Pregnancy-induced hypertension, which leads to ocular manifestations including blurred vision, photopsia, scotoma, and diplopia, might induce reactive changes in the retinal vessels. Although several studies have suggested the existence of pregnancy-induced hypertension-related retinal ocular disease, there are few large cohort studies on this topic. OBJECTIVE: This study aimed to investigate the risk of major retinal diseases including central serous chorioretinopathy, diabetic retinopathy, retinal vein occlusion, retinal artery occlusion, and hypertensive retinopathy in the long-term postpartum stage according to the presence of previous pregnancy-induced hypertension in a large cohort based on the Korean National Health Insurance Database. STUDY DESIGN: On the basis of Korean health data, 909,520 patients who delivered from 2012 to 2013 were analyzed. Among them, patients who had previous ocular diseases or hypertension and multiple births were excluded. Finally, 858,057 mothers were assessed for central serous chorioretinopathy (ICD-10: H35.70), diabetic retinopathy (ICD-10: H36.0, E10.31, E10.32, E11.31, E11.32, E12.31, E13.31, E13.32, E14.31, E14.32), retinal vein occlusion (ICD-10: H34.8), retinal artery occlusion (ICD-10: H34.2), and hypertensive retinopathy (ICD-10: H35.02) for 9 years after delivery. Enrolled patients were divided into 2 groups: 10,808 patients with and 847,249 without pregnancy-induced hypertension. The primary outcomes were the incidence of central serous chorioretinopathy, diabetic retinopathy, retinal vein occlusion, retinal artery occlusion, and hypertensive retinopathy 9 years after delivery. Clinical variables were age, parity, cesarean delivery, gestational diabetes mellitus, and postpartum hemorrhage. In addition, pregestational diabetes mellitus, kidney diseases, cerebrovascular diseases, and cardiovascular diseases were adjusted. RESULTS: Postpartum retinal disease during the 9 years after delivery and total retinal diseases showed higher rates in patients with pregnancy-induced hypertension. In detail, the rates of central serous chorioretinopathy (0.3% vs 0.1%), diabetic retinopathy (1.79% vs 0.5%), retinal vein occlusion (0.19% vs 0.1%), and hypertensive retinopathy (0.62% vs 0.05%) were higher than those found in patients without pregnancy-induced hypertension. After adjusting for confounding factors, pregnancy-induced hypertension was associated with development of postpartum retinopathy, with a >2-fold increase (hazard ratio, 2.845; 95% confidence interval, 2.54-3.188). Furthermore, pregnancy-induced hypertension affected the development of central serous chorioretinopathy (hazard ratio, 3.681; 95% confidence interval, 2.667-5.082), diabetic retinopathy (hazard ratio, 2.326; 95% confidence interval, 2.013-2.688), retinal vein occlusion (hazard ratio, 2.241; 95% confidence interval, 1.491-3.368), and hypertensive retinopathy (hazard ratio, 11.392; 95% confidence interval, 8.771-14.796) after delivery. CONCLUSION: A history of pregnancy-induced hypertension increases the risk of central serous chorioretinopathy, diabetic retinopathy, retinal vein occlusion, and hypertensive retinopathy according to 9-year long-term ophthalmologic follow-up.

Long-term adverse neurodevelopmental outcomes of discordant twins delivered at term: A nationwide population-based study.

OBJECTIVE: To evaluate long-term adverse neurodevelopmental outcomes of discordant twins delivered at term. DESIGN: Retrospective cohort study. SETTING: Nationwide (Republic of Korea). POPULATION: All twin children delivered at term between 2007 and 2010. METHODS: The study population was divided into two groups according to inter-twin birthweight discordancy: the 'concordant twin group', twin pairs with inter-twin birthweight discordancy less than 20%; and the 'discordant twin group', twin pairs with inter-twin birthweight discordancy of 20% or more. The risk of long-term adverse neurodevelopmental outcomes was compared between the concordant twin group and the discordant twin group. Long-term adverse neurodevelopmental outcomes between smaller and larger twin children within twin pairs were further analysed. The composite adverse neurodevelopmental outcome was defined as the presence of at least one of the following: motor developmental delay, cognitive developmental delay, autism spectrum disorders/attention deficit hyperactivity disorders, tics/stereotypical behaviour or epileptic/febrile seizure. MAIN OUTCOME MEASURES: Long-term adverse neurodevelopmental outcome. RESULTS: Of 22 468 twin children (11 234 pairs) included, 3412 (15.19%) twin children were discordant. The risk of composite adverse neurodevelopmental outcome was higher in the discordant twin group than in the concordant twin group (adjusted hazard ratio [HR] 1.13, 95% CI 1.03-1.24). The long-term adverse neurodevelopmental outcomes were not significantly different between smaller and larger twin children in discordant twin pairs (adjusted HR 1.01, 95% CI 0.81-1.28). CONCLUSION: In twin pairs delivered at term, an inter-twin birthweight discordancy of 20% or greater was associated with long-term adverse neurodevelopmental outcomes; and long-term adverse neurodevelopmental outcomes were not significantly different in smaller or larger twin children in discordant twin pairs.

The introduction to air pollution on pregnancy outcome (APPO) study: a multicenter cohort study.

OBJECTIVE: The air pollution on pregnancy outcome (APPO) study is a prospective hospital-based cohort study designed to investigate the maternal and fetal effects of a particulate matter with an aerodynamic below 10 µm (PM10) and PM2.5 (below 2.5 µm) exposure. This study aims to analyze a relationship between particulate matter and adverse pregnancy outcomes and to find related biomarkers and develop management guidelines. METHODS: About 1,200 pregnant women are recruited for 3 years (from January 2021 to December 2023) from seven university hospitals to investigate the effects of particulate matter on pregnancy complications and adverse pregnancy outcomes. We collect biological samples by 5 mL of maternal venous blood and 15 mL of urine in each trimester of pregnancy, and 5 mL of umbilical cord blood and 2×2×2 cm of placental tissue are collected after delivery. In addition, by applying PM10 and PM2.5 concentration values and time-activity patterns from the time weighted average model, the individual predicted exposure of air pollution for the pregnant women are obtained. RESULTS: The average exposure of PM10 and PM2.5 of the participants in the entire period of pregnancy, was exceeded the World Health Organization air quality guidelines (an annual level, PM10 >15 µg/m3, PM2.5 >5 µg/m3). Moreover, it was revealed that the PM concentration was increasing toward the 3rd trimester of pregnancy. CONCLUSION: The APPO study will be able to identify the degree of exposure to air pollution in pregnant women and use it as basic data for estimating individual exposure to particulate matter. And the results of the APPO study will facilitate in the development of health management for pregnant women against air pollution.

The Skin Antiseptic agents at Vaginal dElivery (SAVE) trial: study protocol for a randomized controlled trial.

BACKGROUND: Cleansing of the vulva and perineum is recommended during preparation for vaginal delivery, and special attention is paid to cleansing before episiotomy because episiotomy is known to increase the risk of perineal wound infection and/or dehiscence. However, the optimal method of perineal cleansing has not been established, including the choice of antiseptic agent. To address this issue, we designed a randomized controlled trial to examine whether skin preparation with chlorhexidine-alcohol is superior to povidone-iodine for the prevention of perineal wound infection after vaginal delivery. METHODS: In this multicenter randomized controlled trial, term pregnant women who plan to deliver vaginally after episiotomy will be enrolled. The participants will be randomly assigned to use antiseptic agents for perineal cleansing (povidone-iodine or chlorhexidine-alcohol). The primary outcome is superficial or deep perineal wound infection within 30 days after vaginal delivery. The secondary outcomes are the length of hospital stay, physician office visits, or hospital readmission for infection-related complications, endometritis, skin irritations, and allergic reactions. DISCUSSION: This study will be the first randomized controlled trial aiming to determine the optimal antiseptic agent for the prevention of perineal wound infections after vaginal delivery. TRIAL REGISTRATION: ClinicalTrials.gov NCT05122169. First submitted date on 8 November 2021. First posted date on 16 November 2021.

Metabolic dysfunction-associated fatty liver disease as a risk factor for adverse outcomes in subsequent pregnancy: a nationwide cohort study.

BACKGROUND AND PURPOSE: A recent international expert consensus opinion suggested that metabolic dysfunction-associated fatty liver disease (MAFLD) replaces nonalcoholic fatty liver disease (NAFLD), since MAFLD is a better predictor of cardiovascular disease. We estimated the prevalence of FLD in fertile females and evaluated the clinical impact of either NAFLD or MAFLD on maternal and fetal outcomes during subsequent pregnancy. METHODS: The study population included fertile females who underwent health examinations and became pregnant within 1 year of health examination. Hepatic steatosis was defined as a fatty liver index of ≥ 30. The fertile females were divided into four groups: neither-FLD, NAFLD-only, MAFLD-only, and both-FLDs. During subsequent pregnancy, the risks of adverse pregnancy outcomes, including gestational diabetes, pregnancy-associated hypertension, preterm birth, and low birthweight, were compared among the four groups. RESULTS: The study population comprised 762,401 females, including 720,606 with neither-FLD, 318 with NAFLD-only, 14,371 with MAFLD-only, and 27,106 with both-FLDs. Compared to females with neither-FLD, the risk of adverse pregnancy outcomes was higher in females with any FLD, with an adjusted OR of 1.73 (95% CI 1.25-2.41) in the NALFD-only group, 2.65 (2.53-2.77) in the MAFLD-only group, and 2.39 (2.31-2.48) in the both-FLDs group. Pregnancy outcomes (cesarean delivery, gestational diabetes, and low birthweight) were worse in females with MAFLD compared with NAFLD. CONCLUSION: Any form of FLD is a risk factor for adverse pregnancy outcomes. These data suggest that MAFLD is associated with a higher risk of adverse pregnancy outcomes for both mother and fetus than NAFLD.

Pregnancy outcomes in twin pregnancies over 10 years.

OBJECTIVE: The aim of this study was to evaluate the changes in twin pregnancy outcomes between 2007 and 2016 in a Korean population. METHODS: The data for this nationwide population-based study was obtained from the national birth registry of the Korean National Statistical Office and the Health Insurance Review & Assessment Service of Korea. Women with twin pregnancies who gave birth between 2007 and 2016 were included. RESULTS: From 2007 to 2016, the rate of twin pregnancies increased (1.37% vs. 1.91%, respectively, P<0.0001). The risk of preterm birth (adjusted odds ratio [aOR], 1.77; 95% confidence interval [CI], 1.66-1.89) also increased; however, the risk of twin growth discordance (aOR, 0.90; 95% CI, 0.82-0.99) decreased. The risks of cesarean section (aOR, 1.16; 95% CI, 1.03-1.29), gestational diabetes mellitus (aOR, 2.10; 95% CI, 1.83-2.39), and postpartum hemorrhage (aOR, 1.27; 95% CI, 1.14-1.41) all increased from 2007 to 2016. CONCLUSION: Twin pregnancy outcomes have changed significantly in Korea over a recent 10-year period.

Changes in preterm birth and birthweight during the SARS-CoV-2 pandemic: a nationwide study in South Korea.

Birthweight is a strong determinant of a neonate's health. The SARS-CoV-2 pandemic's impact on birthweight has not been investigated in-depth, with inconsistent conclusions from initial studies. To assess changes in preterm birth and inappropriate birthweight between the SARS-CoV-2 pandemic and pre-pandemic periods. A nationwide birth micro-data consisted with exhaustive census of all births in 2011-2020 in South Korea was accessed to examine whether the mean birthweight and rates of under/overweight births changed significantly during the SARS-CoV-2 pandemic year (2020) compared to those of the pre-pandemic period (2011-2019). A total of 3,736,447 singleton births were analyzed. Preterm birth was defined as < 37 weeks of gestation. Low birthweight (LBW) and macrosomia were defined as birthweights < 2.5 kg and ≥ 4.0 kg, respectively. Small for gestational age (SGA) and large for gestational age (LGA) were defined as birthweights below the 10th and above 90th percentiles for sex and gestational age, respectively. Inappropriate birthweight was defined as one or more LBW, macrosomia, SGA, or LGA. Generalized linear models predicted birth outcomes and were adjusted for parental age and education level, marital status, parity, gestational age, and months from January 2011. There were 3,481,423 and 255,024 singleton births during the pre-pandemic and pandemic periods, respectively. Multivariable generalized linear models estimated negative associations between the pandemic and preterm birth (odds ratio [OR], 0.968; 95% confidence interval [CI] 0.958-0.978), LBW (OR: 0.967, 95% CI 0.956-0.979), macrosomia (OR: 0.899, 95% CI 0.886-0.912), SGA (OR: 0.974, 95% CI 0.964-0.983), LGA (OR: 0.952, 95% CI 0.945-0.959), and inappropriate birthweight (OR: 0.958, 95% CI 0.952-0.963), indicating a decline during the pandemic compared to pre-pandemic period. An 8.98 g decrease in birthweight (95% CI 7.98-9.99) was estimated during the pandemic. This is the largest and comprehensive nationwide study to date on the impact of the SARS-CoV-2 pandemic on preterm birth and inappropriate birthweight. Birth during the pandemic was associated with lower odds of being preterm, underweight, and overweight. Further studies are required to understand the dynamics underlying this phenomenon.

COVID-19 and vaccination during pregnancy: a systematic analysis using Korea National Health Insurance claims data.

OBJECTIVE: This study systematically analyzed coronavirus disease 2019 (COVID-19) and vaccination details during pregnancy by using the national health insurance claims data. METHODS: Population-based retrospective cohort data of 12,399,065 women aged 15-49 years were obtained from the Korea National Health Insurance Service claims database between 2019 and 2021. Univariate analysis was performed to compare the obstetric outcomes of pregnant women (ICD-10 O00-O94) and their newborns (ICD-10 P00-P96) with and without COVID-19. Univariate analysis was also performed to compare the age and obstetric outcomes of pregnant women receiving different types of vaccines. RESULTS: The percentage of pregnant women with COVID-19 during pregnancy was 0.11%. Some obstetric outcomes of pregnant women with COVID-19, including the rates of preterm birth or cesarean delivery, were significantly better than those of pregnant women without COVID-19. The rate of miscarriage was higher in pregnant women with COVID-19 than without COVID-19. However, the outcomes of newborns of women with and without COVID-19 were not significantly different. Regarding vaccination type, obstetric outcomes of pregnant women appeared to be worse with the viral vector vaccine than with the mRNA vaccine. CONCLUSION: To the best of our knowledge, this is the first study to systematically analyze COVID-19 and vaccination details during pregnancy using the national health insurance claims data in Korea. The obstetric outcomes in pregnant women with and without COVID-19 and their newborns were similar.