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.

Urinary metabolite biomarkers of pregnancy complications associated with maternal exposure to particulate matter

Particulate matter 2.5 (PM2.5) is associated with reproductive health and adverse pregnancy outcomes. However, studies evaluating biological markers of PM2.5 are lacking, and identifying biomarkers for estimating prenatal exposure to prevent pregnancy complications is essential. Therefore, we aimed to explore urine metabolites that are easy to measure as biomarkers of exposure. In this matched case-control study based on the PM2.5 exposure, 30 high PM2.5 group (>15 μg/m3) and 30 low PM2.5 group (<15 μg/m3) were selected from air pollution on pregnancy outcome (APPO) cohort study. We used a time-weighted average model to estimate individual PM exposure, which used indoor PM2.5 and outdoor PM2.5 concentrations by atmospheric measurement network based on residential addresses. Clinical characteristics and urine samples were collected from participants during the second trimester of pregnancy. Urine metabolites were quantitatively measured using gas chromatography-mass spectrometry following multistep chemical derivatization. Statistical analyses were conducted using SPSS version 21 and MetaboAnalyst 5.0. Small for gestational age and gestational diabetes (GDM) were significantly increased in the high PM2.5 group, respectively (P = 0.042, and 0.022). Fifteen metabolites showed significant differences between the two groups (P < 0.05). Subsequent pathway enrichment revealed that four pathways, including pentose and glucuronate interconversion with three pentose sugars (ribose, arabinose, and xylose; P < 0.05). The concentration of ribose increased preterm births (PTB) and GDM (P = 0.044 and 0.049, respectively), and the arabinose concentration showed a tendency to increase in PTB (P = 0.044). Therefore, we identified urinary pentose metabolites as biomarkers of PM2.5 and confirmed the possibility of their relationship with pregnancy 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, those 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: 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.

Maternal PM2.5 exposure is associated with preterm birth and gestational diabetes mellitus, and mitochondrial OXPHOS dysfunction in cord blood

Maternal exposure to fine particulate matter (PM2.5) is associated with adverse pregnancy and neonatal health outcomes. To explore the mechanism, we performed mRNA sequencing of neonatal cord blood. From an ongoing prospective cohort, Air Pollution on Pregnancy Outcome (APPO) study, 454 pregnant women from six centers between January 2021 and June 2022 were recruited. Individual PM2.5 exposure was calculated using a time-weighted average model. In the APPO study, age-matched cord blood samples from the High PM2.5 (˃15 ug/m3; n = 10) and Low PM2.5 (≤ 15 ug/m3; n = 30) groups were randomly selected for mRNA sequencing. After selecting genes with differential expression in the two groups (p-value < 0.05 and log2 fold change > 1.5), pathway enrichment analysis was performed, and the mitochondrial pathway was analyzed using MitoCarta3.0. The risk of preterm birth (PTB) increased with every 5 µg/m3 increase of PM2.5 in the second trimester (odds ratio 1.391, p = 0.019) after adjusting for confounding variables. The risk of gestational diabetes mellitus (GDM) increased in the second (odds ratio 1.238, p = 0.041) and third trimester (odds ratio 1.290, p = 0.029), and entire pregnancy (odds ratio 1.295, p = 0.029). The mRNA-sequencing of cord blood showed that genes related to mitochondrial activity (FAM210B, KRT1, FOXO4, TRIM58, and FBXO7) and PTB-related genes (ADIPOR1, YBX1, OPTN, NFkB1, HBG2) were upregulated in the High PM2.5 group. In addition, exposure to high PM2.5 affected mitochondrial oxidative phosphorylation (OXPHOS) and proteins in the electron transport chain, a subunit of OXPHOS. These results suggest that exposure to high PM2.5 during pregnancy may increase the risk of PTB and GDM, and dysregulate PTB-related genes. Alterations in mitochondrial OXPHOS by high PM2.5 exposure may occur not only in preterm infants but also in normal newborns. Further studies with larger sample sizes are required.

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.

Correction: Park et al. Effect of Particulate Matter 2.5 on Fetal Growth in Male and Preterm Infants through Oxidative Stress. Antioxidants 2023, 12, 1916

In the original publication [...].

Fasting glucose variability and risk of dementia in Parkinson's disease: a 9-year longitudinal follow-up study of a nationwide cohort

Background

Diabetes is associated with an increased risk of Parkinson's disease dementia (PDD); however, it is unknown whether this association is dependent on continuous hyperglycemia, hypoglycemic events, or glycemic variability. We aimed to investigate the relationship between visit-to-visit fasting glucose variability and PDD development in patients with Parkinson's disease (PD).

Methods

Using data from the Korean National Health Insurance Service, we examined 9,264 patients aged ≥40 years with de novo Parkinson's disease (PD) who underwent ≥3 health examinations and were followed up until December 2019. Glucose variability was measured using the coefficient of variation, variability independent of the mean, and average real variability. Fine and Gray competing regression analysis was performed to determine the effect of glucose variability on incident PDD.

Results

During the 9.5-year follow-up period, 1,757 of 9,264 (19.0%) patients developed PDD. Patients with a higher visit-to-visit glucose variability had a higher risk of future PDD. In the multivariable adjusted model, patients with PD in the highest quartile (subdistribution hazard ratio [SHR] = 1.50, 95% CI 1.19 to 1.88), quartile 3 (SHR = 1.29, 95% CI 1.02 to 1.62), and quartile 2 (SHR = 1.30, 95% CI 1.04 to 1.63) were independently associated with a higher risk of PDD than those in the lowest quartile.

Conclusion

We highlighted the effect of long-term glucose variability on the development of PDD in patients with PD. Furthermore, our findings suggest that preventive measures for constant glucose control may be necessary to prevent PDD.

Short-term Impact of Hormone Replacement Therapy on Risk of Breast Cancer in BRCA Mutation Carriers: A Nationwide Study in South Korea

PURPOSE

BRCA1/2 mutations are well-known risk factors for breast and ovarian cancers in women. Risk-reducing salpingo-oophorectomy (RRSO) is the standard treatment for preventing ovarian cancer with BRCA mutations. Postmenopausal syndrome (symptoms after RRSO can be alleviated by hormone replacement therapy (HRT); however, the use of HRT in carriers of BRCA mutations has been controversial because of the concern that HRT increases the risk of breast cancer. This study aimed to evaluate the effects of HRT in BRCA mutation carriers who underwent RRSO.

MATERIALS AND METHODS

A total of 151 carriers, who underwent RRSO between 2013 and 2020 after the diagnosis of BRCA1 or BRCA2 mutations were selected and followed up for a median of 3.03 years. Patients were divided into two groups: those who received HRT after RRSO (n=33) and those who did not (n=118). We compared the incidence of breast cancer over time between these two groups.

RESULTS

There was no significant difference in the incidence of breast cancer between women who received HRT and those who did not (p=0.229). Multivariate logistic regression analysis, adjusted for age and parity revealed no significant difference in the risk of breast cancer between these two groups (hazard ratio, 0.312; 95% confidence interval, 0.039 to 2.480; p=0.278).

CONCLUSION

In this study, we found no relationship between post-RRSO HRT and breast cancer in the population with BRCA mutations. Therefore, healthcare providers may consider the alleviation of symptoms of postmenopausal syndrome through HRT in patients who underwent RRSO.

Association between cardiac arrhythmia before pregnancy and gestational diabetes: a nationwide population-based study in Korea

Given the higher prevalence of cardiac arrhythmias in individuals with diabetes, we investigated the relationship between cardiac arrhythmias and the incidence of gestational diabetes (GDM). This retrospective cohort study utilized data from the Korean Health Insurance Service database, encompassing 1,113,729 women who gave birth between January 2007 and December 2015. After excluding those who did not undergo National Health Screening tests within 1 year prior to pregnancy, those with multifetal pregnancies, and those diagnosed with diabetes, we analyzed 365,880 singleton pregnancies without a history of diabetes. Of these, 3,253 (0.9%) had cardiac arrhythmias, including premature extra beats, supraventricular tachyarrhythmias, and/or atrial flutter/fibrillation. GDM occurred in 31,938 (8.7%) subjects during pregnancy, and was more prevalent in women with cardiac arrhythmia than in those without (14.9% vs. 8.7%, p<0.001). In the multivariate analysis, the association between cardiac arrhythmia and GDM remained statistically significant (adjusted odds ratio, 1.78; 95% CI, 1.615-1.970; p<0.001). Subgroup analysis revealed that the risk of GDM was consistently statistically significant in subjects with cardiac arrhythmia, regardless of age, body mass index, and the presence or absence of chronic hypertension. Therefore, cardiac arrhythmias before and during pregnancy appear to be associated with an increased risk of developing GDM.

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.

Risk of adverse obstetric outcomes in patients with a history of endometrial cancer: A nationwide population-based cohort study

OBJECTIVE

To evaluate adverse obstetric outcomes in women with a history of endometrial cancer (EC).

DESIGN

Population-based cohort study.

SETTING

The Korean National Health Insurance (KNHI) claims database.

POPULATION

Women who gave birth between 2009 and 2016, with a history of EC prior to pregnancy.

METHODS

The KNHI database was used to compare obstetric outcomes of women with and without a history of EC, using the ICD-10 codes. Multivariable logistic regression models were used to determine the associations between a history of EC and adverse obstetric outcomes.

MAIN OUTCOMES MEASURES

Adverse obstetric outcomes.

RESULTS

Overall, 248 and 3 335 359 women with and without a history of EC, respectively, gave birth. When adjusted for age, primiparity and comorbidities, an increased risk of multiple gestations (odds ratio [OR] 4.925, 95% confidence interval [CI] 3.394-7.147), caesarean delivery (OR 2.005, 95% CI 1.535-2.62) and preterm birth (OR 1.941, 95% CI 1.107-3.404) was observed among women with a history of EC. We were unable to demonstrate significant differences in the risk of pre-eclampsia, gestational diabetes, vacuum delivery, placenta praevia, placenta accreta spectrum, placental abruption and postpartum haemorrhage between the groups. In the sensitivity analyses excluding multiple gestations, an increased risk of preterm birth was not observed among women with a history of EC (OR 1.276, 95% CI 0.565-2.881).

CONCLUSIONS

There is no convincing evidence of an increased risk of adverse obstetric outcomes among women with a history of EC. Our findings would be useful in counselling of patients with EC who are undergoing fertility-sparing treatment.

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.

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.

Effect of Particulate Matter 2.5 on Fetal Growth in Male and Preterm Infants through Oxidative Stress

Particulate matter 2.5 (PM2.5) levels are associated with adverse pregnancy outcomes. In this retrospective cohort study, we examined whether the concentration of indoor PM2.5 affected pregnancy outcomes. Additionally, we evaluated biomarkers of pregnancy-related complications caused by fine dust. We collected clinical information and data based on residential addresses from the Air Korea database to assess PM2.5 exposure levels. As a multicenter prospective cohort study, we measured the indoor PM2.5 concentration and inflammatory and oxidative stress markers. The PM2.5 concentration of the low-birth-weight (LBW) delivery group was 27.21 μg/m3, which was significantly higher than that of the normal-birth-weight (NBW) group (26.23 μg/m3) (p = 0.02). When the newborns were divided by sex, the PM2.5 concentration of the LBW group was 27.89 μg/m3 in male infants, which was significantly higher than that of the NBW group (26.26 μg/m3) (p = 0.01). In the prospective study, 8-hydroxy-2-deoxyguanosine significantly increased in the high-concentration group (113.55 ng/mL, compared with 92.20 ng/mL in the low-concentration group); in the high-concentration group, the rates of preterm birth (PTB) and small size for gestational age significantly increased (p < 0.01, p = 0.01). This study showed an association between PM2.5, oxidative stress, and fetal growth, with the PTB group being more vulnerable.

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.

Effect of Tablet-based Cognitive Intervention on Cognition in Patients With Mild Cognitive Impairment: A Pilot Study

Background and Purpose

Growing evidence has shown that cognitive interventions can mitigate cognitive decline in patients with mild cognitive impairment (MCI). However, most previous cognitive interventions have been group-based programs. Due to their intrinsic limitations, group-based programs are not widely used in clinical practice. Therefore, we have developed a tablet-based cognitive intervention program. This preliminary study investigated the feasibility and effects of a 12-week structured tablet-based program on cognitive function in patients with MCI.

Methods

We performed a single-arm study on 24 patients with MCI. The participants underwent a tablet-based cognitive intervention program 5 times a week over a 12-week period. The primary outcome was changes in cognitive function, measured using the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet (CERAD-K). Outcomes were evaluated at baseline, within two weeks of the last program (post-intervention), and at the six-month follow-up session.

Results

The completion rate of the tablet-based program was 83.3% in patients with MCI. The program improved cognitive function based on the CERAD-K total score (p=0.026), which was maintained for at least three months (p=0.004). There was also an improvement in the depression scale score (p=0.002), which persisted for three months (p=0.027).

Conclusions

Our 12-week structured tablet-based program is feasible for patients with MCI. Furthermore, although further studies with a double-arm design are required, the program appears to be an effective strategy to prevent cognitive decline in patients with MCI.

Long-Term Effect on Ovarian Function After Uterine Artery Embolization During the Postpartum Period: A Nationwide Population-Based Study

Uterine artery embolization(UAE) is widely used in obstetrical indications, including postpartum bleeding and placental implantation abnormality, to manage many conditions to conserve the uterus. However, physicians are concerned about future fertility or ovarian function due to the occlusion of major pelvic vessels in the uterine artery embolization. However, there are limited data related to UAE usage during the postpartum period. This study was to evaluate the impact of UAE during the postpartum period on primary ovarian failure(POF), menstrual disorders, and infertility in women. Using the Korea National Health Insurance claims database, all pregnant women who delivered between January 2007 and December 2015 and underwent UAE during the postpartum period were identified. The occurrence of POF, female infertility, and menstrual disorders after delivery was evaluated. Using Cox proportional hazards models, the adjusted hazard ratios and 95% confidence intervals were estimated. 779,612 cases were analyzed in the study with 947 women in the UAE group. After delivery, the incidence of POF (0.84% vs.0.27%, P<.0001) and female infertility (10.24% vs. 6.89%, P<.0001) were higher in UAE group than in the control group. After adjusting for covariates, the POF risk was significantly higher in UAE group than in the control group (HR 2.37, 95% CI 1.16-4.82). The risk for the disorder of menstrual frequency (HR 1.28, 95% CI 1.10-1.50) and female infertility (HR 1.37, 95% CI 1.10-1.71) was significantly higher in UAE group than in the control group. This study confirmed UAE during the postpartum period is a risk factor for POF after delivery.

The Effect of Vanishing Twin on First- and Second-Trimester Maternal Serum Markers and Nuchal Translucency: A Multicenter Prospective Cohort Study

BACKGROUND

The purpose of this study was to evaluate the effect of vanishing twin (VT) on maternal serum marker concentrations and nuchal translucency (NT).

METHODS

This is a secondary analysis of a multicenter prospective cohort study in 12 institutions. Serum concentrations of pregnancy-associated plasma protein-A in the first trimester and alpha-fetoprotein (AFP), total human chorionic gonadotrophin, unconjugated estriol, and inhibin A in the second trimester were measured, and NT was measured between 10 and 14 weeks of gestation.

RESULTS

Among 6,793 pregnant women, 5,381 women were measured for serum markers in the first or second trimester, including 65 cases in the VT group and 5,316 cases in the normal singleton group. The cases in the VT group had a higher median multiple of the median value of AFP and inhibin A than the normal singleton group. The values of other serum markers and NT were not different between the two groups. After the permutation test with adjustment, AFP and inhibin A remained significant differences. The frequency of abnormally increased AFP was also higher in the VT group than in the normal singleton group.

CONCLUSION

VT can be considered as an adjustment factor for risk assessment in the second-trimester serum screening test.

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.

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.

Declining incidence of cerebral palsy in South Korea

Presuming that the incidence of cerebral palsy (CP) in Korea is decreasing due to medical advances, we analyzed the trends and risk factors of CP in changing circumstances. We identified all women who delivered a singleton between 2007 and 2015 using the Korea National Health Insurance (KNHI). Information on pregnancy and birth was obtained by linking the KNHI claims database and data from the national health-screening program for infants and children. The 4-years incidence of CP decreased significantly from 4.77 to 2.52 per 1000 babies during the study period. The multivariate analysis revealed that the risk of developing CP was 29.5 times higher in preterm infants born before 28 weeks of gestational age, 24.5 times higher in infants born between 28 and 34 weeks, and 4.5 times higher in infants born between 34 and 36 weeks, compared to full-term appropriate for age (2.5 ~ 4 kg of body weight) infants. 5.6 times higher in those with birth weight < 2500 g, and 3.8 times higher in pregnancies with polyhydramnios. Additionally, respiratory distress syndrome increased the risk of developing CP by 2.04 times, while necrotizing enterocolitis was associated with a 2.80-fold increased risk of CP. In Korea, the incidence of CP in singleton decreased from 2007 to 2015. We need to continue to focus on developing medical technologies for the early detection of high-risk neonates and minimizing brain damage to reduce the incidence rate of CP effectively.

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.

Vulnerable newborn types: Analysis of population-based registries for 165 million births in 23 countries, 2000-2021

OBJECTIVE

To examine the prevalence of novel newborn types among 165 million live births in 23 countries from 2000 to 2021.

DESIGN

Population-based, multi-country analysis.

SETTING

National data systems in 23 middle- and high-income countries.

POPULATION

Liveborn infants.

METHODS

Country teams with high-quality data were invited to be part of the Vulnerable Newborn Measurement Collaboration. We classified live births by six newborn types based on gestational age information (preterm <37 weeks versus term ≥37 weeks) and size for gestational age defined as small (SGA, <10th centile), appropriate (10th-90th centiles), or large (LGA, >90th centile) for gestational age, according to INTERGROWTH-21st standards. We considered small newborn types of any combination of preterm or SGA, and term + LGA was considered large. Time trends were analysed using 3-year moving averages for small and large types.

MAIN OUTCOME MEASURES

Prevalence of six newborn types.

RESULTS

We analysed 165 017 419 live births and the median prevalence of small types was 11.7% - highest in Malaysia (26%) and Qatar (15.7%). Overall, 18.1% of newborns were large (term + LGA) and was highest in Estonia 28.8% and Denmark 25.9%. Time trends of small and large infants were relatively stable in most countries.

CONCLUSIONS

The distribution of newborn types varies across the 23 middle- and high-income countries. Small newborn types were highest in west Asian countries and large types were highest in Europe. To better understand the global patterns of these novel newborn types, more information is needed, especially from low- and middle-income countries.

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-β-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.

Maternal Polycystic Ovary Syndrome and the Risk of Early Childhood Obesity in Female Offspring: A Nationwide Population-Based Study

BACKGROUND

To investigate the relationship between polycystic ovary syndrome (PCOS) in Korean women and childhood growth and obesity of their offspring.

METHODS

This longitudinal case-control study using the Korean National Health Insurance claims database and the National Health Screening Program for Infants and Children database included women who delivered singletons between January 2007 and December 2008. Offspring's body mass index (BMI) measurements taken between 42 and 80 months of age were compared according to a maternal history of PCOS.

RESULTS

Among a total of 131,805 participants, 1,213 women had a history of PCOS and 130,592 women did not. Female offspring aged 66-80 months born to women with PCOS had significantly higher BMI than those born to women without PCOS; there was no significant difference in that of male offspring regardless of maternal PCOS. In the generalized estimating equation and multivariable logistic regression analyses, the female offspring born to women with PCOS had a significantly higher risk of obesity during the age of 42-54 and 66-80 months (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.09-2.21 and OR, 1.5; 95% CI, 1.05-2.15, respectively), than those born to women without PCOS, after adjusting for several confounding factors.

CONCLUSION

Maternal PCOS is independently associated with an increased incidence of childhood obesity in female offspring among Korean women. Women with PCOS should consider the risk of early childhood obesity in their daughters, even if they maintain a healthy weight themselves.

Independent effect of cardiometabolic syndromes and depression on dementia in Parkinson's disease: A 12-year longitudinal follow-up study of a nationwide cohort

BACKGROUND

We aimed to investigate the incidence rate of Parkinson's disease dementia (PDD) according to age and disease duration by sex. Furthermore, we explored the effect of each cardiometabolic syndrome and depression on the incidence of PDD.

METHODS

Using data from the Korean National Health Insurance Service, 79,622 patients with de novo Parkinson's disease (PD) aged ≥40 years between January 2002 and December 2010 were followed to December 2019. We analyzed the incidence of PDD according to age at PD diagnosis and disease duration. To determine cardiometabolic syndromes and depression that affected PDD, we used Fine and Gray competing regression after controlling for age and sex.

RESULTS

During the 12.5-year follow-up period, the incidence of PDD increased with age at PD diagnosis (0.81-45.31 per 1000 person-years among those aged 40-44 and over 80 years, respectively) and longer disease duration (22.68 per 1000 person-years in 1-2 years to 34.16 per 1000 person-years in 15-16 years). Hypertension (subdistribution hazard ratio [SHR] = 1.11; 95% confidence interval [CI] 1.07-1.16), diabetes (SHR = 1.09; 95% CI 1.05-1.14), dyslipidemia (SHR = 1.15; 95% CI 1.11-1.20), and depression (SHR = 1.36; 95% CI 1.30-1.41) independently increased the risk for PDD.

CONCLUSIONS

Our findings provide insights into cardiometabolic syndromes as modifiable risk factors for incident PDD. Furthermore, our results will help in designing public health policies with respect to controlling cardiometabolic syndromes and depression to prevent incident PDD in patients with PD.

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

The air pollution on pregnancy outcome, (APPO) study is a prospective hospital-based cohort study designed to investigate the maternal and fetal effects of particulate matter with an aerodynamic diameter <10 μm (PM10) and particulate matter with an aerodynamic diameter below 10 μm <2.5 μm (PM2.5) exposure. Specifically, approximately 1,200 pregnant women will be recruited for 3 years to collect data on exposure to fine dust, and the methods for measuring exposure to fine particles for each pregnant woman and estimating output will be established. This study aims to analyze the relationship between particulate matter and adverse pregnancy outcomes, identify related biomarkers, and develop management guidelines. We recruited early pregnant women without underlying diseases and collected biological samples using 5 mL of maternal venous blood and 15 mL of urine in each trimester of pregnancy; in addition, 5 mL of umbilical cord blood and 2×2×2 cm of placental tissue were collected after delivery. By applying PM10 and PM2.5 and time-activity patterns from the time-weighted average model, the individual predicted exposure to air pollution for the pregnant women was obtained. The APPO study can identify the degree of exposure to air pollution in pregnant women and use it as basic data for estimating individual exposure to particulate matter. The results of this APPO study will facilitate the development of health management strategies 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.

Incidence of Parkinson's disease and modifiable risk factors in Korean population: A longitudinal follow-up study of a nationwide cohort

Introduction

We aimed to investigate the incidence of Parkinson's disease (PD) by age and year for each sex as well as the modifiable risk factors for PD. Using data from the Korean National Health Insurance Service, 938,635 PD and dementia-free participants aged ≥40 years who underwent general health examinations were followed to December 2019.

Methods

We analyzed the PD incidence rates according to age, year and sex. To investigate the modifiable risk factors for PD, we used the Cox regression model. Additionally, we calculated the population-attributable fraction to measure the impact of the risk factors on PD.

Results

During follow-up, 9,924 of the 938,635 (1.1%) participants developed PD. The incidence of PD increased continuously from 2007 to 2018, reaching 1.34 per 1,000 person-years in 2018. The incidence of PD also increases with age, up to 80 y. Presence of hypertension (SHR = 1.09, 95% CI 1.05 to 1.14), diabetes (SHR = 1.24, 95% CI 1.17 to 1.31), dyslipidemia (SHR = 1.12, 95% CI 1.07 to 1.18), ischemic stroke (SHR = 1.26, 95% CI 1.17 to 1.36), hemorrhagic stroke (SHR = 1.26, 95% CI 1.08 to 1.47), ischemic heart disease (SHR = 1.09, 95% CI 1.02 to 1.17), depression (SHR = 1.61, 95% CI 1.53 to 1.69), osteoporosis (SHR = 1.24, 95% CI 1.18 to 1.30), and obesity (SHR = 1.06, 95% CI 1.01 to 1.10) were independently associated with a higher risk for PD.

Discussion

Our results highlight the effect of modifiable risk factors for PD in the Korean population, which will help establish health care policies to prevent the development of PD.

Chromosomal Abnormality, fetal/neonatal Death and Socioeconomic Status: A Prospective Cohort Study

OBJECTIVES

To assess the risk gradient of chromosomal abnormalities and fetal or neonatal death across a socioeconomic spectrum of pregnant women.

METHODS

We used the data from the Korean Prenatal Diagnosis Study (KPDS), which included singleton pregnancies who were candidates for fetal aneuploidy screening enrolled from the Seoul Capital Area from December 2016 to April 2018. We analyzed chromosomal abnormalities which were diagnosed pre- or postnatally, and fetal or neonatal death. The highest level of education among the women and the average monthly household income were used as proxies for socioeconomic status.

RESULTS

Among the 6,715 women, the majority of were 30-39 years old and university graduates, with a reported household income higher than the national median. Chromosomal abnormalities occurred in 45 women (6.7 per 1,000). Fetal or neonatal death occurred in 70 (11.3 per 1,000), excluding pregnancies affected by chromosomal abnormality diagnosis. The adjusted odds ratio for chromosomal abnormalities was higher when household income was < 4,484 USD per month. For fetal or neonatal death, the risk estimates for lower education and lower household income were generally positive but remained imprecise.

CONCLUSION

We observed some evidence of an inverse association between the risk of fetal chromosomal abnormality and level of household income in a prospective cohort of pregnant women. Interventions to reduce socioeconomic disparities in perinatal health should focus on those with a low household income.

Applications of artificial intelligence in obstetrics

Artificial intelligence, which has been applied as an innovative technology in multiple fields of healthcare, analyzes large amounts of data to assist in disease prediction, prevention, and diagnosis, as well as in patient monitoring. In obstetrics, artificial intelligence has been actively applied and integrated into our daily medical practice. This review provides an overview of artificial intelligence systems currently used for obstetric diagnostic purposes, such as fetal cardiotocography, ultrasonography, and magnetic resonance imaging, and demonstrates how these methods have been developed and clinically applied.

Long-term risks of coronary heart disease and cerebrovascular disease in ovarian, uterine and cervical cancer survivors: a nationwide study in Korea

Only few studies have evaluated the incidence of coronary heart disease (CHD) and cerebrovascular disease (CVD) among gynaecologic cancer survivors. We selected 26,880 gynaecologic cancer patients who underwent health check-ups within 2 years after diagnosis using the Korean National Health Insurance Service Database. They were compared with 79,830 non-cancer controls. Cox regression models were used to estimate hazard ratios (HRs). There was no significant relationship between gynaecologic cancer survivors and CHD or CVD events. However, 10 years after diagnosing cancers, the risk of angina increased in cancer survivors (adjusted HR = 1.193, 95% CI: 1.013-1.406). After 1 year of diagnosis, cancer patients with no initial comorbidities showed an increased risk of all CHD and CVD events (adjusted HR = 1.101, 95% CI: 1.020-1.189) and CHD alone (adjusted HR = 1.168, 95% CI: 1.055-1.293) compared with controls. CHD risk was also higher in the cancer group with no comorbidities after 10 years of diagnosis (adjusted HR = 1.284, 95% CI: 1.020-1.615). Overall, the risk of CHD or CVD did not increase in gynaecologic cancer survivors. However, cancer patients without any comorbidities showed a higher risk of CHD compared with control, the risk persisting until 10 years after cancer diagnosis.Impact StatementWhat is already known on this subject? Cardiovascular risk and the incidence of stroke increase after cancer diagnosis.What do the results of this study add? The risk of coronary heart disease (CHD) and cerebrovascular disease did not increase in Asian (especially Korean) gynaecologic cancer survivors compared with the general population. However, cancer patients without any comorbidities showed a higher risk of CHD compared with the non-cancer population.What are the implications of these findings for clinical practice and/or further research? Our results imply the importance of surveillance of cardiovascular risks among patients with gynaecologic cancer without comorbidities.

Hydroxychloroquine reduces hypertension and soluble fms-like kinase-1 in a Nω-nitro-l-arginine methyl ester-induced preeclampsia rat model

OBJECTIVE

Hydroxychloroquine, a drug used for malaria and autoimmune diseases reportedly has beneficial effects against preeclampsia in pregnant women with lupus. However, its mechanism against preeclampsia remains unclear. We investigated the effect of hydroxychloroquine on an Nω-nitro-l-arginine methyl ester-induced preeclampsia rat model.

METHODS

Pregnant Sprague-Dawley rats were divided into four groups based on treatment (administered on gestational days 7-18): control, Nω-nitro-l-arginine methyl ester, hydroxychloroquine, and Nω-nitro-l-arginine methyl ester plus hydroxychloroquine. All animals were sacrificed on gestational day 19. We assayed tube formation and determined reactive oxygen species levels using human umbilical vein endothelial cells.

RESULTS

Results showed that hydroxychloroquine significantly lowered mean systolic blood pressure (P  < 0.05) in Nω-nitro-l-arginine methyl ester-treated rats. Hydroxychloroquine did not affect their fetal and placental weights. Hydroxychloroquine mitigated Nω-nitro-l-arginine methyl ester-associated changes in proteinuria (P  < 0.05). It normalized plasma soluble fms-like kinase-1 (P  < 0.05) and endothelin-1 (P  < 0.01) levels. In the tube formation assay, hydroxychloroquine increased the total meshes area (P  < 0.05) and mitigated Nω-nitro-l-arginine methyl ester-induced reactive oxygen species formation (P  < 0.05) in human umbilical vein endothelial cells.

CONCLUSION

We conclude that hydroxychloroquine alleviated hypertension, proteinuria, and normalized soluble fms-like kinase-1 and endothelin-1 levels in our preeclampsia model and that these changes may involve the restoration of endothelial dysfunction; thus, hydroxychloroquine could potentially be used for preventing preeclampsia, even in the absence of lupus.

Pregnancy outcomes of immigrant women living in Korea: A population-based study

Although there is a high rate of pregnant immigrant women in Korea, little is known regarding their pregnancy outcomes. The aim of this study was to evaluate the pregnancy outcomes of immigrant women in Korea. Data for all pregnant women who gave birth between January 1, 2007 and December 31, 2016 were obtained using the Health Insurance Review and Assessment Service Database. Pregnant women were divided into two groups: Korean and immigrant women. The main outcome measures were adverse pregnancy outcomes including gestational diabetes of mellitus, preeclampsia, cesarean section, placental abrnomalities, and postpartum hemorrhage. The odds of gestational diabetes mellitus, preeclampsia, cesarean section, placental previa, placental abruptio, and postpartum hemorrhage was compared between the two groups. Among 4,439,778 pregnant women who gave birth during the study period, 168,940 (3.8%) were immigrant women. The odds of gestational diabetes mellitus (adjusted OR: 1.24; 95% CI: 1.21, 1.28), and cesarean section (adjusted OR: 1.26; 95% CI: 1.25-1.28)were higher in immigrant women than in Korean women, but the odds of preeclampsia (adjusted OR: 0.84; 95% CI: 0.81-0.86) and postpartum hemorrhage (adjusted OR 0.96, 95% CI 0.94-0.97) was lower in immigrant women than in Korean women. Immigrant women had different pregnancy outcomes. Pregnancy and postpartum management that reflects these characteristics will be necessary for immigrant women.

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.

Myocardial Infarction, Stroke, and All-Cause Mortality according to Low-Density Lipoprotein Cholesterol Level in the Elderly, a Nationwide Study

BACKGROUND

We assessed the myocardial infarction (MI), stroke, and all-cause death risks during follow-up according to the low-density lipoprotein cholesterol (LDL-C) levels among older adults.

METHODS

The Korean National Health Insurance Service datasets (2002 to 2020) were used for this population-based cohort study. The hazards of MI, stroke, and all-cause mortality during follow-up were analyzed according to LDL-C level in individuals aged ≥65 years without baseline cardiovascular diseases (n=1,391,616).

RESULTS

During a mean 7.55 years, 52,753 MIs developed; 84,224 strokes occurred over a mean 7.47 years. After a mean 8.50 years, 233,963 died. A decrease in LDL-C was associated with lower hazards of MI and stroke. The decreased hazard of stroke in lower LDL-C was more pronounced in statin users, and individuals with diabetes or obesity. The hazard of all-cause death during follow-up showed an inverted J-shaped pattern according to the LDL-C levels. However, the paradoxically increased hazard of mortality during follow-up in lower LDL-C was attenuated in statin users and individuals with diabetes, hypertension, or obesity. In statin users, lower LDL-C was associated with a decreased hazard of mortality during follow-up.

CONCLUSION

Among the elderly, lower LDL-C was associated with decreased risks of MI and stroke. Lower LDL-C achieved by statins in the elderly was associated with a decreased risk of all-cause death during follow-up, suggesting that LDL-C paradox for the premature death risk in the elderly should not be applied to statin users. Intensive statin therapy should not be hesitated for older adults with cardiovascular risk factors including diabetes.

A Predictive Model for Large-for-Gestational-Age Infants among Korean Women with Gestational Diabetes Mellitus Using Maternal Characteristics and Fetal Biometric Parameters

Background: With increasing incidence of gestational diabetes mellitus (GDM), newborn infants with perinatal morbidity, including large-for-gestational-age (LGA) or macrosomia, are also increasing. The purpose of this study was to develop a prediction model for LGA infants with GDM mothers. Methods: This was a retrospective case-control study of 660 women with GDM and singleton pregnancies in four tertiary care hospitals from 2006 to 2013 in Korea. Biometric parameters were obtained at diagnoses of GDM and within two weeks before delivery. These biometric data were all transformed retrospectively into Z-scores calculated using a reference. Interval changes of values between the two periods were obtained. Multivariable logistic and stepwise backwards regression analyses were performed to develop the most parsimonious predictive model. The prediction model included pre-pregnancy body mass index (BMI), head circumference (HC), Z-score at 24 + 0 to 30 + 6 weeks’ gestation, and abdominal circumference (AC) Z-score at 34 + 0 to 41 + 6 weeks within 2 weeks before delivery. The developed model was then internally validated. Results: Our model’s predictive performance (area under the curve (AUC): 0.925) was higher than estimated fetal weight (EFW) within two weeks before delivery (AUC: 0.744) and the interval change of EFW Z-score between the two periods (AUC: 0.874). It was internally validated (AUC: 0.916). Conclusions: A clinical model was developed and internally validated to predict fetal overgrowth in Korean women with GDM, which showed a relatively good performance.

Prenatal Diagnosis of Congenital Heart Diseases and Associations with Serum Biomarkers of Aneuploidy: A Multicenter Prospective Cohort Study

PURPOSE

We assessed prenatal detection rates of congenital heart disease (CHD) and associations between maternal serum biomarkers and non-chromosomal CHD in singleton pregnancies.

MATERIALS AND METHODS

This study was conducted as a secondary analysis of data obtained during a multicenter prospective cohort study that investigated the cost-effectiveness of prenatal testing for fetal aneuploidy. We analyzed the prenatal detection rate and accuracy for CHD screening via ultrasound during the second trimester, as well as associations between serum biomarkers and CHDs, in singleton newborns without chromosomal abnormalities.

RESULTS

Among 6715 women, 142 (2.1%) newborns were born with CHDs, of which 67 (1.0%) newborns had major CHDs. The prenatal detection rate for all CHDs and major CHDs were 34.5% and 58.2%, respectively. After excluding isolated ventricular septal defects, the detection rate for critical CHDs was 85.9%. Women with low pregnancy-associated plasma protein A (PAPP-A) (<0.4 multiples of the median, MOM) face increased risks of non-chromosomal CHDs [adjusted odds ratio (aOR) 2.76; 95% confidence interval (CI) 1.36-5.13] and major CHDs (aOR 7.30; 95% CI 3.18-15.59), compared to those without CHDs. A higher inhibin A level (≥2.5 MOM; aOR 4.84; 95% CI 1.42-12.46) was associated with non-chromosomal major CHDs.

CONCLUSION

Ultrasonography performed during the second trimester by obstetricians detected over 85% of critical CHDs. Low maternal serum PAPP-A or high inhibin-A was associated with non-chromosomal CHDs. These results may contribute to an improvement in prenatal diagnosis of CHDs.

Short-term neonatal and long-term infant outcome of late-preterm twins: nationwide population-based study

OBJECTIVES

To evaluate the short- and long-term outcome of late-preterm compared with term birth in twin pregnancy.

METHODS

This retrospective observational cohort study included all women who had a twin delivery between 1 January 2007 and 31 December 2010 recorded in the claims database of the Korea National Health Insurance, with at least one follow-up recorded in the database of the National Health Screening Program for Infants and Children. Outcomes were analyzed at the pregnancy level, with adverse outcome being defined as an adverse outcome in one or both twins, identified by a diagnosis according to the International Classification of Diseases 10^th Revision. The primary short-term outcome was composite morbidity, which included any of the following: transient tachypnea, respiratory distress syndrome, necrotizing enterocolitis, intraventricular hemorrhage and bronchopulmonary dysplasia. Long-term adverse outcome included any neurological or neurodevelopmental outcome, defined by prespecified neurological and developmental diagnoses; these were assessed by following up all neonates until the end of 2018, by which time they were 8-11 years of age. Outcomes were compared between twins delivered late preterm (34 + 0 to 36 + 6 weeks) and those delivered at term (≥ 37 weeks).

RESULTS

Among 17 189 women who delivered twins at ≥ 34 weeks of gestation during the study period, 5032 (29.27%) women delivered in the late-preterm period. On multivariate analysis, compared with the twins delivered at term, the late-preterm twins had an increased risk for the primary short-term outcome of composite morbidity (adjusted odds ratio (aOR), 2.09; 95% CI, 1.90-2.30), including transient tachypnea (aOR, 1.85; 95% CI, 1.64-2.09), respiratory distress syndrome (aOR, 2.31; 95% CI, 2.04-2.62), necrotizing enterocolitis (aOR, 2.10; 95% CI, 1.20-3.69) and intraventricular hemorrhage (aOR, 2.13; 95% CI, 1.46-3.11). For the long-term outcome, the late-preterm twins also had an increased risk for any neurological or neurodevelopmental outcome (adjusted hazard ratio, 1.14; 95% CI, 1.07-1.21).

CONCLUSIONS

Twins delivered in the late-preterm period have an increased risk for short- and long-term morbidity compared with twins delivered at term. These results should be considered when determining the timing of delivery in uncomplicated twin pregnancy. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

The risk for future cerebrovascular disease in pregnant women with Moyamoya disease: a nationwide population-based study in South Korea

Background

Physiologic changes during pregnancy affect the development of postpartum cerebrovascular disease (CVD) in women with Moyamoya disease. Due to the rare prevalence of Moyamoya disease and its large regional variations, large-scale based studies on the risk of CVD after delivery have not been conducted. This study aimed to evaluate whether women with Moyamoya disease have an increased risk of CVD after delivery.

Methods

Research data was collected from the National Health Insurance Claims Database of the Health Insurance Review and Assessment Service. Patients who delivered in Korea from 2007 to 2014 were enrolled in this study. We classified women as having CVD if they were diagnosed with any of the following conditions between delivery and December 31, 2016; cerebral infarction (I63.X in the International Classification of Diseases-10th Revision [ICD-10]) and/or intracranial hemorrhage (I61.X, I62.X in ICD-10) and/or subarachnoid hemorrhage (I60.X in ICD-10). Women with Moyamoya disease were identified as having I67.5 in ICD-10. We matched the study cohort by the ratio of 1:10 to analyze the risk CVD occurrence. The matching technique applied in this study was based on the variables of age and parity. To evaluate the adjusted hazard ratio (HR) for CVD in women with Moyamoya disease, we used multivariate Cox proportional hazard regression.

Results

Among a total of 3,611,216 Korean women who underwent delivered, we identified 412 women with Moyamoya disease diagnosis and 1420 age- and parity-matched women without Moyamoya disease (control). Compared to the control group, women with Moyamoya disease had a significantly higher rate of Cesarean section, overt DM, and essential hypertension (all p < 0.0001). Among women with Moyamoya disease, 55 (13.35%) women developed CVD within the follow-up postpartum period. The presence of Moyamoya disease was associated with an increased risk of CVD after delivery (adjusted HR 37.42; 95% confidence interval (CI) 17.50-80.02 within 2.3 years) after adjusting for pregnancy-induced hypertension, gestational diabetes mellitus, pregestational diabetes, chronic hypertension.

Conclusion

This population based study showed that the occurrence rate of CVD after delivery was higher in women with Moyamoya disease than in those without. Therefore, careful and long-term postpartum surveillance is required for women with Moyamoya disease.

Anti-Viral Activities of Umbilical Cord Mesenchymal Stem Cell-Derived Small Extracellular Vesicles Against Human Respiratory Viruses

The endemic and pandemic caused by respiratory virus infection are a major cause of mortality and morbidity globally. Thus, broadly effective antiviral drugs are needed to treat respiratory viral diseases. Small extracellular vesicles derived from human umbilical cord mesenchymal stem cells (U-exo) have recently gained attention as a cell-free therapeutic strategy due to their potential for safety and efficacy. Anti-viral activities of U-exo to countermeasure respiratory virus-associated diseases are currently unknown. Here, we tested the antiviral activities of U-exo following influenza A/B virus (IFV) and human seasonal coronavirus (HCoV) infections in vitro. Cells were subject to IFV or HCoV infection followed by U-exo treatment. U-exo treatment significantly reduced IFV or HCoV replication and combined treatment with recombinant human interferon-alpha protein (IFN-α) exerted synergistically enhanced antiviral effects against IFV or HCoV. Interestingly, microRNA (miR)-125b, which is one of the most abundantly expressed small RNAs in U-exo, was found to suppress IFV replication possibly via the induction of IFN-stimulated genes (ISGs). Furthermore, U-exo markedly enhanced RNA virus-triggered IFN signaling and ISGs production. Similarly, human nasal epithelial cells cultured at the air-liquid interface (ALI) studies broadly effective anti-viral and anti-inflammatory activities of U-exo against IFV and HCoV, suggesting the potential role of U-exo as a promising intervention for respiratory virus-associated diseases.

Prior pregnancy complications and maternal cardiovascular disease in young Korean women within 10 years after pregnancy

BACKGROUND

This study aimed to compare obstetric outcomes in Korean women with and without future cardiovascular disease (CVD) within 10 years after pregnancy, and assessed whether pregnancy complications are independent risk factors, and whether the combination of pregnancy complications has an additive function for risk factors for CVD.

METHODS

This was a nationwide population-based study combining the database of the Korea National Health Insurance claims and National Health Screening Programs to assess preeclampsia, low birth weight (LBW), and preterm delivery as risk factors for CVD. Cox proportional hazards models was used to evaluate the risk of total CVD, ischemic heart disease (IHD), and stroke after the pregnancy complications, with adjustment for potential confounding variables.

RESULTS

Women with CVD were likely to have a higher prevalence of pregnancy complications than women without CVD. The risk of total CVD was associated with preeclampsia (adjusted hazard ratio (HR), 1.60 [95% confidence interval (CI) 1.50-1.72]), LBW (1.20 [1.12-1.28]), and preterm delivery (1.32 [1.22-1.42]), after adjustment for confounders, including cardiovascular risk factors before pregnancy. The risk estimates of pregnancy complications for IHD were higher than those for stroke. In this study, the risk of total CVD was higher in the combined presence of preeclampsia and preterm delivery (2.23 [1.57-3.17] or all three complications (2.06 [1.76-2.40]), relative to no complications. The highest HR was noted in the risk of all pregnancy complications for IHD (2.39 [1.98-2.89]).

CONCLUSION

Preeclampsia, preterm delivery, and LBW were independently associated with CVD in young Korean women. In addition, the combination of pregnancy complications had less-than-additive effects on CVD incidence.

Pre-pregnancy blood pressure and pregnancy outcomes: a nationwide population-based study

Background

Hypertension has been known to increase the risk of obstetric complications. Recently, the American College of Cardiology endorsed lower thresholds for hypertension as systolic blood pressure of 130-139 mmHg or diastolic blood pressure 80-89 mmHg. However, there is a paucity of information regarding the impact of pre-pregnancy blood pressure on pregnancy outcomes. We aimed to evaluate the effect of pre-pregnancy blood pressure on maternal and neonatal complications.

Methods

In this nationwide, population based study, pregnant women without history of hypertension and pre-pregnancy blood pressure < 140/90 mmHg were enrolled. The primary outcome of composite morbidity was defined as any of the followings: preeclampsia, placental abruption, stillbirth, preterm birth, or low birth weight.

Results

A total of 375,305 pregnant women were included. After adjusting for covariates, the risk of composite morbidity was greater in those with stage I hypertension in comparison with the normotensive group (systolic blood pressure, odds ratio = 1.68, 95% CI: 1.59 – 1.78; diastolic blood pressure, odds ratio = 1.56, 95% CI: 1.42 – 1.72). There was a linear association between pre-pregnancy blood pressure and the primary outcome, with risk maximizing at newly defined stage I hypertension and with risk decreasing at lower blood pressure ranges.

Conclusions

‘The lower, the better’ phenomenon was still valid for both maternal and neonatal outcomes. Our results suggest that the recent changes in diagnostic thresholds for hypertension may also apply to pregnant women. Therefore, women with stage I hypertension prior to pregnancy should be carefully observed for adverse outcomes.

Increased Risk of Type 2 Diabetes in Patients With Thyroid Cancer After Thyroidectomy: A Nationwide Cohort Study

CONTEXT

Abnormal thyroid function after thyroidectomy and subsequent thyroid-stimulating hormone suppression can have detrimental effects on glucose homeostasis in patients with thyroid cancer.

OBJECTIVE

To investigate whether thyroidectomy increases the risk of type 2 diabetes in patients with thyroid cancer and to explore the association between levothyroxine dosage and type 2 diabetes risk.

METHODS

A retrospective population-based cohort study using the Korean National Health Insurance database. We included 36 377 thyroid cancer patients without known diabetes who underwent thyroidectomy between 2004 and 2013. Matched subjects with nonthyroid cancer were selected using 1:1 propensity score matching. The main outcome measure was newly developed type 2 diabetes mellitus.

RESULTS

Patients with thyroid cancer who underwent thyroidectomy had a higher risk of developing type 2 diabetes mellitus than the matched controls (hazard ratio [HR] 1.43, 95% CI 1.39-1.47). Among patients with thyroid cancer, when the second quartile group (in terms of the mean levothyroxine dosage; 101-127 μg/day) was considered the reference group, the risk of type 2 diabetes mellitus increased in the first quartile (<101 μg/day; HR 1.45, 95% CI 1.36-1.54) and fourth quartile groups (≥150 μg/day; HR 1.37, 95% CI 1.29-1.45); meanwhile, the risk decreased in the third quartile group (128-149 μg/day; HR 0.91, 95% CI 0.85-0.97).

CONCLUSION

Patients with thyroid cancer who underwent thyroidectomy were more likely to develop type 2 diabetes mellitus than the matched controls. There was a U-shaped dose-dependent relationship between the levothyroxine dosage and type 2 diabetes mellitus risk.

Increased Cardiac Arrhythmia After Pregnancy-Induced Hypertension: A South Korean Nationwide Database Study

Background

Although pregnancy‐induced hypertension (PIH) is associated with an elevated cardiovascular risk, long‐term studies or prepregnancy baseline data are scarce. Therefore, using a large nationwide cohort with prepregnancy periodic health screening data, we investigated whether clinically significant arrhythmia incidence increases after PIH.

Methods and Results

Data were extracted from the Korea National Health Insurance database and combined with the National Health Screening Examination database; women who gave birth between 2007 and 2015 and underwent the national health screening test within a year before pregnancy were followed up until 2016. We excluded women who had a diagnosis of arrhythmia within 1 year before pregnancy. The primary outcome was significant arrhythmia during the year after delivery. Secondary analysis included only specific diagnostic codes of arrhythmia with clinical significance. Additionally, the risk of arrhythmia was stratified by the use of magnesium sulfate. Of 2 035 684 women (PIH; n=37 297 versus normotensive pregnancy; n=1 998 387), the PIH group had a higher prepregnancy risk profile and showed a higher incidence of arrhythmia than women with normotensive pregnancies within 1 year. Women with PIH had a significantly higher risk of atrial flutter/fibrillation and atrioventricular block, but not lethal arrhythmias. Other predictors of arrhythmia development included advanced maternal age and cesarean section. Stratified analysis showed a higher risk of arrhythmia with magnesium sulfate use.

Conclusions

PIH was significantly associated with the development of arrhythmia within 1 year after delivery. Nevertheless, the incidence of lethal arrhythmias was not increased by PIH. Arrhythmia, especially atrial fibrillation, may largely contribute to increasing the future cardiovascular risk in women with a PIH history.