Relationship between maternal mortality and ritodrine hydrochloride as a tocolytic agent in Japan.

AIM: In Japan, unlike Western countries, tocolytic agents are administered in long-term protocols to treat threatened preterm labor. Evaluating the side effects of this practice is crucial. We examined whether ritodrine hydrochloride had been administered in cases of maternal death, aiming to investigate any relationship between ritodrine administration and maternal death. METHODS: This retrospective cohort study used reports of maternal deaths from multiple institutions in Japan between 2010 and 2020. Data on the reported cases were retrospectively analyzed, and data on the route of administration, administered dose, and clinical findings, including causes of maternal death, were extracted. The amount of tocolytic agents was compared between maternal deaths with ritodrine administration and those without. RESULTS: A total of 390 maternal deaths were reported to the Maternal Death Exploratory Committee in Japan during the study period. Ritodrine hydrochloride was administered in 32 of these cases. The frequencies (n) and median doses (range) of oral or intravenous ritodrine hydrochloride were 34.4% (11) and 945 (5-2100) mg and 84.4% (27) and 4032 (50-18 680) mg, respectively. Frequencies of perinatal cardiomyopathy, cerebral hemorrhage, diabetic ketoacidosis, and pulmonary edema as causes of maternal death were significantly higher with ritodrine administration than without it. CONCLUSIONS: Our results suggest a relationship between long-term administration of ritodrine hydrochloride and an increased risk of maternal death due to perinatal cardiomyopathy, cerebral hemorrhage, diabetic ketoacidosis, and pulmonary edema. In cases where ritodrine should be administered to prevent preterm labor, careful management and monitoring of maternal symptoms are required.

Effects of sturgeon fillet intake on top-ranked Japanese female long-distance runners.

AIMS: The aim of this study is to investigate whether consumption of sturgeon fillets reduces the oxidative stress marker urinary 8-hydroxy-2'-deoxyguanosine (8OHdG) in top-ranked Japanese female long-distance runners. METHODS: In a before-and-after study, nine professional long-distance female athletes ate 100 g/day of sturgeon fillets for 2 weeks. Urinalysis (8OHdG, an oxidative stress marker, and creatinine), blood tests (fatty acids and 25-hydroxyvitamin D [25OHD]), exercise intensity, subjective fatigue, muscle elasticity, muscle mass, body fat mass, and nutritional intake using image-based dietary assessment (IBDA) were compared before, immediately after, and 1 month after the intervention. RESULTS: Consumption of sturgeon fillets suppressed 8OHdG (p < 0.05) in the increased exercise intensity female athletes. Eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and 25OHD levels in blood increased from before to immediately after and 1 month after the intervention (p < 0.05). IBDA showed that intake of n-3 fatty acid increased after and one month after the intervention, whereas DHA, imidazole dipeptide and vitamin D intake increased after the intervention (p < 0.05) and then decreased after 1 month (p < 0.05). There were no significant changes in subjective fatigue, muscle elasticity, muscle mass, and body fat. CONCLUSIONS: The results suggest that eating sturgeon fillets during intense training may increase blood levels of EPA, DHA, and 25OHD, which may suppress urinary oxidative stress (8OHdG) in top-ranked Japanese long-distance runners.

Reference range for C1-esterase inhibitor (C1 INH) in the third trimester of pregnancy.

OBJECTIVES: The objectives of this study were to (i) establish the reference range and mean value for normal levels of C1-esterase inhibitor (C1 INH) during pregnancy, and (ii) investigate the association between C1 INH and uterine atony, as measured by blood loss at delivery. METHODS: We prospectively studied 200 healthy pregnant women who were registered. We studied C1 INH levels in 188 women at 34 and 35 gestational weeks of pregnancy. The reference range for C1 INH during the third trimester of pregnancy was calculated using the value of C1 INH that was determined at registration. RESULTS: The mean value of C1 INH was determined to be 70.3% (95% confidence interval, 68.7-71.9). While the C1 INH levels in four women were determined to be 40% lower than the calculated mean value, amniotic fluid embolism (AFE) did not occur in any of the women studied. CONCLUSIONS: This study successfully demonstrated that a reference value for C1 INH activity can be established using the methods described herein. Further research is needed to determine whether C1 INH is involved in obstetric coagulopathy syndrome such as amniotic fluid embolism.

Pulmonary thromboembolism during pregnancy and puerperium: Comparison of survival and death cases.

AIM: In Japan, the frequency of maternal deaths due to obstetric hemorrhage has been decreasing in the last decade, while that resulting from other causes such as pulmonary thromboembolism (PTE) was consistent. To help reduce maternal deaths due to PTE, we investigated PTE during pregnancy and puerperium and compared the survival and death cases, and aimed to find out life and death factors. METHODS: This study was a retrospective analysis based on a clinical chart review in 407 maternal and perinatal centers. We compared the survival and death cases of PTE during pregnancy and puerperium from 2013 to 2017. RESULTS: In PTE during pregnancy, the survival cases underwent significantly earlier diagnoses than the death cases, and thromboprophylaxis was performed in most of both the survival and death cases of PTE during puerperium according to the existing Japanese guidelines; however, only one fourth of the total cases underwent anticoagulation to prevent venous thromboembolism (VTE). CONCLUSIONS: Early diagnosis of PTE in suspected cases was associated with better survival during pregnancy.

Pregnancy-associated hemorrhagic stroke: A nationwide survey in Japan.

AIM: The number of maternal deaths due to pregnancy-associated hemorrhagic stroke has not decreased despite a gradual decrease of maternal death in Japan. This study aimed to clarify the risk factors of hypertensive disorders of pregnancy-associated hemorrhagic stroke. METHODS: This retrospective study analyzed pregnancy-associated hemorrhagic stroke patients with hypertensive disorders of pregnancy between 2013 and 2017 among 407 Japanese maternal and perinatal centers. Patients were divided into good or poor outcome groups and their maternal backgrounds and neonatal prognoses were compared. RESULTS: We analyzed 61 cases, including 41 survival and 20 death cases, obtained from a secondary survey. Among the 61 hemorrhagic stroke cases, 62% were related to hypertensive disorders. Hypertensive disorders of pregnancy were observed in 75% of death cases. Use of MgSO4 or antihypertensive medication did not differ between the poor and good outcomes groups. In cases with antepartum onset of hypertensive disorders of pregnancy, outcomes were poor in 12 and good in 6 cases. Nine patients with poor outcomes and one with a good outcome had hypertension at the outpatient department without systemic evaluation (p = 0.043). Six poor outcomes patients and one good outcome spent more than 1 day from diagnosis at an outpatient clinic. Neurosurgery was performed in 11 poor outcome patients. CONCLUSION: Pregnant women who present with a hypertensive disorder at an outpatient clinic probably need to undergo blood tests and careful observation. Delayed systemic evaluation and intensive care for only a few days may result in the development of hemorrhage.

Aortic dissection during pregnancy and puerperium: A Japanese nationwide survey.

AIM: This study aimed to characterize the incidence and clinical significance of pregnancy-related aortic dissection using a large-scale survey in Japan. METHODS: A questionnaire requesting the detailed information included in the clinical charts of pregnancy-related aortic dissection cases (without any personally identifying information) was designed between 2013 and 2017 and administered to 407 perinatal centers in Japan. The response rate was 70.5%. Seventeen cases of pregnancy-related aortic dissection were identified. RESULTS: Maternal death due to aortic dissection was observed in nine patients (56.2%) while seven survived (43.8%). Dissection occurred during the postpartum period in 10 cases (62.5%), the third trimester in 4 (25.0%), labor in 1 (6.2%), and the second trimester in 1 (6.2%). The most common underlying diseases were: Marfan syndrome (25.0%), Loeys-Dietz syndrome (6.2%), hypertension (6.2%), and Takayasu aortitis (6.2%). Stanford type A aortic dissection was associated with maternal death during both pregnancy and the postpartum period. However, deceased patients showed lower rates of pre-diagnosed connective tissue disease than did survivors. CONCLUSIONS: The mortality rate of aortic dissection that occurred during pregnancy or postnatal periods was more than 50%. Aortic dissection occurred more frequently in the postnatal period than during pregnancy, and less frequently in women previously diagnosed with connective tissue disease than in women without any medical history of aortic disorders. If symptoms suggestive of aortic dissection, such as severe back pain, are observed, even after the end of pregnancy, exhaustive diagnostic examinations should be carried out.

Relationship between thin physique at 6 years and metabolic disease risks in middle-aged Japanese women: The Suita study.

AIM: We previously reported that female babies born small developed cardiovascular risks in middle age. The present study was conducted using the same cohort to examine the relationship between physique at 6 years and the metabolic disease risk in middle age. METHODS: Data collected from 721 women aged 41-69 years who underwent a medical examination at a single institution between 2007 and 2008 were retrospectively examined. We collected data from medical examinations and a questionnaire on physique (thin, normal, and fat) at 6 years. The relationship between birthweight and physique at 6 years was investigated. RESULTS: Among females who were born small (< 2500 g), 80%, 16%, and 4% became thin, normal, or fat, respectively, by 6 years. Physique at 6 years had a negative relationship with future triglyceride, fasting glucose, HbA1C , insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) levels and a positive relationship with high-density lipoprotein cholesterol levels. CONCLUSION: Although our findings may be specific to the study population, physique at 6 years had a negative relationship with the metabolic disease risk in middle-aged Japanese women. Insulin and MOMA-IR levels negatively correlated with physique at 6 years, and development from low birthweight infants to childhood obesity was rare in this cohort.

Tadalafil Treatment Ameliorates Hypoxia and Alters Placental Expression of Proteins Downstream of mTOR Signaling in Fetal Growth Restriction.

Background and Objectives: Fetal growth restriction (FGR) is associated with fetal mortality and is a risk factor for cerebral palsy and future lifestyle-related diseases. Despite extensive research, no effective treatment strategy is available for FGR. Mammalian target of rapamycin (mTOR) signaling is important for the growth of fetal organs and its dysregulation is associated with miscarriage. Here, we focused on mTOR signaling and investigated how the activities of phospho-ribosomal protein S6 (rps6) and phospho-eukaryotic translation initiation factor 4E (eIF-4E), which act downstream of mTOR signaling in the human placenta, change following treatment of FGR with tadalafil and aimed to elucidate the underlying mechanism of action. Placental hypoxia was investigated by immunostaining for hypoxia-inducible factor (HIF)-2α. Materials and Methods: Phosphor-rps6 and phosphor-eIF4E expression were examined by Western blotting and enzyme-linked immunosorbent assay, respectively. Results: HIF-2α expression significantly increased in FGR placenta compared with that in the control placenta but decreased to control levels after tadalafil treatment. Levels of phospho-rps6 and phospho-eIF-4E were significantly higher in FGR placenta than in control placenta but decreased to control levels after tadalafil treatment. Conclusions: Tadalafil restored the levels of HIF-2α, phospho-rps6, and eIF-4E in FGR placenta to those observed in control placenta, suggesting that it could be a promising treatment strategy for FGR.

The most common causative bacteria in maternal sepsis-related deaths in Japan were group A Streptococcus: A nationwide survey.

The present retrospective study provides an in-depth analysis of the maternal sepsis-related deaths reported in Japan, and aims to guide future care regarding maternal sepsis. This is a nationwide, retrospective, descriptive cohort study. Data were retrospectively analyzed on all maternal death cases related to sepsis reported in Japan from 2010 through 2016. A total of 7,347,727 births and 317 maternal deaths were reported during the study period. The cause of maternal death was sepsis in 24 women (7.5%). Causative bacteria were Streptococcus pyogenes (54.2%), Chlamydia psittaci (8.3%), Mycobacterium tuberculosis (8.3%), Escherichia coli (4.2%), Neisseria meningitidis (4.2%), Epstein-Barr virus (4.2%), and unknown (16.6%). In maternal death due to S. pyogenes (13 women), onset periods ware antepartum in 10 women (76.9%) and postpartum in 3 (23.1%); death within 24 h after hospital admission occurred in 7 women (53.8%); and the median time from hospital admission to death was 12 h (6-744 h). The most common causative bacteria in to maternal sepsis-related death were GAS. When encountering severe sepsis during the peripartum period, we recommend considering severe GAS infection and early intervention.

Cardiovascular profile and biophysical profile scores predict short-term prognosis in infants with congenital heart defect.

AIM: To predict the prognosis of infants with congenital heart disease, accurate prenatal diagnosis of structural abnormality and heart failure are both necessary. The aim of this study was to investigate whether cardiovascular profile (CVP) and biophysical profile (BP) scores are useful for predicting prognosis in infants with congenital heart defect (CHD). METHODS: A retrospective review of singletons prenatally diagnosed with CHD at a tertiary pediatric cardiac center between 2011 and 2015 was undertaken. RESULTS: A total of 202 patients with CHD were analyzed. Perinatal and infant deaths occurred in 16 (7.9%) and 10 cases (5.0%), respectively. Infants with the last CVP score ≤ 5 had 18.7-fold higher perinatal mortality than those with a last CVP score > 5 (P < 0.01). Infants with a last BP score ≤ 6 had 18.7-fold higher perinatal mortality than those with a last BP score > 6 (P < 0.01). Infants with a CVP score decrease in utero had 4.5-fold higher infant mortality than those with an increase or no change (P < 0.01). Multivariate analysis showed that single-ventricle physiology, pre-term birth at <37 weeks of gestation, last CVP score ≤ 5, and last BP score ≤ 6 were independent predictors of perinatal mortality. Single-ventricle physiology and a CVP score decrease were independent predictors of infant mortality. CONCLUSION: CVP and BP scores are useful for predicting perinatal prognosis in infants with CHD. A CVP score decrease in utero is associated with infant mortality, suggesting that serial CVP score assessment may be useful for management planning.

Relationship between reproductive medicine for women with severe complications and maternal death in Japan.

AIM: To investigate the influence of reproductive medicine in maternal death cases in Japan. METHODS: This retrospective study investigated the incidence of maternal deaths related to reproductive medicine in Japan from 2013 to 2015, and the relationship between fertility treatment and maternal death. RESULTS: Fifteen out of 134 women (11.2%) involved in this study who underwent treatment for infertility died. Four experienced pregnancy with severe maternal complications (26.6%). The complications were active systemic lupus erythematosus, exacerbated depression, uncontrolled arrhythmia and uncontrolled type 2 diabetes mellitus. At least three of these four died due to these complications. CONCLUSION: The maternal death rate of women who have undergone fertility treatment is similar to the birth rate due to assisted reproductive technology in Japan. Some maternal death cases involve severe uncontrolled complications. Therefore, medical histories should be evaluated before fertility treatment.

Management of pregnancy complicated with intracranial arteriovenous malformation.

AIM: To clarify the perinatal outcomes in pregnancy complicated with intracranial arteriovenous malformation (i-AVM). METHODS: A retrospective study was performed in 36 pregnancies complicated by i-AVM from 1981 to 2013 at one institution. RESULTS: In total, 6 women miscarried, and 30 had live births. The median (range) gestational age at delivery was 38 (24-40) weeks; 11 cases experienced initial i-AVM rupture during pregnancy (first, second and third trimester: 18%, 64% and 18%, respectively). At onset, 4 cases had a Glasgow Coma Scale ≤10, 10 cases needed emergency maternal transport, 4 underwent neurosurgery with the fetus in utero and 4 had termination of pregnancy in the second trimester for emergent treatment for i-AVM. Two cases delivered vaginally. Another 25 cases had already been diagnosed as i-AVM at conception. Of these, as an indication for epidural birth, 18 cases had either residual lesion of i-AVM or neurological symptoms, although 18 cases had received treatments of i-AVM before conception. Without rupture of i-AVM and worsening of symptoms, 15 cases succeeded in epidural birth. One case was delivered by cesarean section for residual i-AVM with indication of treatment. Another case who had refused treatment of i-AVM experienced rupture of i-AVM 1 year after delivery. CONCLUSION: Most of the cases with residual i-AVM lesion and neurological symptoms could deliver vaginally without worsening of symptoms. However, pregnancy with i-AVM can be complicated by rupture of i-AVM. In cases with a residual lesion with indication of treatment and rupture of i-AVM during pregnancy, meticulous care is required during pregnancy and after delivery.

The first genome-wide association study identifying new susceptibility loci for obstetric antiphospholipid syndrome.

Antiphospholipid syndrome (APS) is the most important treatable cause of recurrent pregnancy loss. The live birth rate is limited to only 70-80% in patients with APS undergoing established anticoagulant therapy. Lupus anticoagulant (LA), but not anticardiolipin antibody (aCL), was found to predict adverse pregnancy outcome. Recent genome-wide association studies (GWAS) of APS focusing on aCL have shown that several molecules may be involved. This is the first GWAS for obstetric APS focusing on LA. A GWAS was performed to compare 115 Japanese patients with obstetric APS, diagnosed according to criteria of the International Congress on APS, and 419 healthy individuals. Allele or genotype frequencies were compared in a total of 426 344 single-nucleotide polymorphisms (SNPs). Imputation analyses were also performed for the candidate regions detected by the GWAS. One SNP (rs2288493) located on the 3'-UTR of TSHR showed an experiment-wide significant APS association (P=7.85E-08, OR=6.18) under a recessive model after Bonferroni correction considering the number of analyzed SNPs. Another SNP (rs79154414) located around the C1D showed a genome-wide significant APS association (P=4.84E-08, OR=6.20) under an allelic model after applying the SNP imputation. Our findings demonstrate that a specific genotype of TSHR and C1D genes can be a risk factor for obstetric APS.

Birthweight and cardiovascular risk factors in a Japanese general population.

AIM: This study was conducted to examine whether babies born small develop cardiovascular problems in later life. METHODS: Data were examined retrospectively for 1241 city dwellers (men 521, women 720) aged 40-69 years who received a medical examination at a single institution. Blood tests, physical measurements, and a questionnaire survey regarding birth weight (small, medium, large), medication history and lifestyle (alcohol consumption, smoking, exercise) was administered. We selected 28 persons (12 men and 16 women) from and studied the rate of conformity between the participants' memory (small, medium, large) and the actual birth weight recorded in their maternal and child health handbook (< 2500, 2500-3500, > 3500 g). RESULTS: Participants' recall of their birth weight correlated well with the weight recorded in the maternal notebook (r = 0.73; P < 0.025). Low-density lipoprotein (P < 0.05), and total cholesterol (P < 0.01) levels in men, and systolic (P < 0.05) and diastolic (P < 0.05) blood pressure in women were significantly inversely related to birth weight when controlling for age, body mass index, medication, and lifestyle. The percentage of women born small, medium, and large taking antidiabetic agents was 17.8%, 2.9% and 0% (P < 0.05), respectively. CONCLUSION: A low birth weight was associated with high low-density lipoprotein and total cholesterol levels in men, and hypertension and diabetes mellitus in women aged 40-69.

Efficacy of transfusion with fresh-frozen plasma:red blood cell concentrate ratio of 1 or more for amniotic fluid embolism with coagulopathy: a case-control study.

BACKGROUND: The Japan Association of Obstetricians and Gynecologists (JAOG) recommends transfusion with a fresh-frozen plasma (FFP):red blood cell (RBC) ratio of 1 or more in postpartum hemorrhage. However, no global consensus exists concerning this, and little is known regarding the impact of FFP:RBC ratio on maternal mortality. This study evaluates the efficacy of transfusion with FFP:RBC ratio of 1 or more for amniotic fluid embolism (AFE) with coagulopathy. STUDY DESIGN AND METHODS: The Maternal Death Exploratory Committee, established by the JAOG, conducted this retrospective nationwide case-control study in Japan. Women with AFE and coagulopathy were included in the study and were stratified into survival and death groups. Obstetric variables and therapy methods (hysterectomy, uterine artery embolism, and transfusion with FFP:RBC ratio ≥ 1) were compared between the survival and death groups. RESULTS: A total of 54 women had AFE and coagulopathy (death group, n = 22; survival group, n = 32). Only nine (40.9%) women in the death group were transfused with FFP:RBC ratio of 1 or more, whereas 29 (90.6%) women in the survival group were transfused with FFP:RBC ratio of 1 or more. FFP:RBC ratio of 1 or more was found to be associated with better survival rate (adjusted odds ratio, 28.32; 95% confidence interval, 4.26-188.37). No difference was found in obstetric variables, hysterectomy, and uterine artery embolism between survival and death groups. CONCLUSION: Transfusion with FFP:RBC ratio of 1 or more is associated with higher survival rate in women with AFE with coagulopathy.

Beta-Blockers and Fetal Growth Restriction in Pregnant Women With Cardiovascular Disease.

BACKGROUND: The effects of ß-adrenergic blockers on the fetus are not well understood. We analyzed the maternal and neonatal outcomes of ß-adrenergic blocker treatment during pregnancy to identify the risk of fetal growth restriction (FGR). METHODS AND RESULTS: We retrospectively reviewed 158 pregnancies in women with cardiovascular disease at a single center. Maternal and neonatal outcomes were analyzed in 3 categories: the carvedilol (α/ß-adrenergic blocker; α/ß group, n=13); ß-adrenergic blocker (ß group, n=45), and control groups (n=100). Maternal outcome was not significantly different between the groups. FGR occurred in 1 patient (7%) in the α/ß group, in 12 (26%) in the ß group, and in 3 (3%) in the control group; there was a significant difference between the incidence of FGR between the ß group and control group (P<0.05). The ß group included propranolol (n=22), metoprolol (n=12), atenolol (n=6), and bisoprolol (n=5), and the individual incidence of FGR with these medications was 36%, 17%, 33%, and 0%, respectively. CONCLUSIONS: As a group, ß-adrenergic blockers were significantly associated with FGR, although the incidence of FGR varied with individual ß-blocker. Carvedilol, an α/ß-adrenergic blocker, had no association with FGR. More controlled studies are needed to fully establish such associations. (Circ J 2016; 80: 2221-2226).

Recommendations for saving mothers' lives in Japan: Report from the Maternal Death Exploratory Committee (2010-2014).

To make recommendations for saving mothers' lives, issues related to maternal deaths including diseases, causes, treatments, and hospital and regional systems are analyzed by the Maternal Death Exploratory Committee in Japan. In this report, we present ten clinical important recommendations based on the analysis of maternal deaths between 2010 and 2014 in Japan.

Maternal Death Due to Stroke Associated With Pregnancy-Induced Hypertension.

BACKGROUND: The aim of this study was to clarify the clinical features of maternal death due to stroke associated with pregnancy-induced hypertension (PIH) in Japan. METHODS AND RESULTS: Reported maternal deaths occurring between 2010 and 2012 throughout Japan were analyzed by the Maternal Death Exploratory Committee. Among a total of 154 reports of maternal death, those due to stroke with (n=12) or without (n=13) PIH were compared. Cerebral stroke occurred more frequently in the third trimester and during the second stage of labor in deaths with PIH, whereas it occurred at any time point in deaths not involving PIH. Although 83% of patients with PIH who died had experienced initial symptoms in a hospital, more than half of them required maternal transport due to lack of medical resources. Among the patients without PIH, some vascular abnormalities were identified, but no evidence was found among the patients with PIH. In addition, 58% of PIH cases resulting in stroke were complicated by hemolysis, elevated liver enzymes and low platelet count (HELLP) syndrome. CONCLUSIONS: Appropriate management of PIH during pregnancy and labor, including anti-hypertensive therapy and early maternal transport to tertiary hospital, may reduce the maternal death rate.

Increase in maternal death-related venous thromboembolism during pregnancy in Japan (2010-2013).

BACKGROUND: The aim of the present work was to understand the current circumstances of maternal-death-related venous thromboembolism (MD-VTE) in Japan. We retrospectively investigated the characteristics of cases of MD-VTE, and compared past and present rates of occurrence. METHODS AND RESULTS: We examined the Japanese data for MD-VTE in 2010-2013, and compared it with that from 1991-1992. MD-VTE occurred in 17 women in 1991-1992, and in 13 women in 2010-2013. The maternal mortality ratio of MD-VTE was 0.7 per 100,000 in 1991-1992 and 0.4 per 100,000 in 2010-2013. Both the maternal mortality ratio and rate of MD-VTE in 2010-2013 deceased significantly compared with 1991-1992 (P<0.05). However, the number of cases of MD-VTE during pregnancy was 6 among 13 women (41%) in 2010-2013, but 1 in 17 women (6%) in 1991-1992, showing an increase (P<0.05). In the present study, cesarean delivery was more frequently associated with MD-VTE. CONCLUSIONS: MD-VTE overall has decreased within the past 20 years in Japan. But, MD-VTE during pregnancy in 2010-2013 increased relative to 1991-1992. Future guidelines for prevention of VTE may need to extend beyond the perioperative period to decrease the incidence of MD-VTE.

Fetal bradyarrhythmia associated with congenital heart defects - nationwide survey in Japan.

BACKGROUND: Because there is limited information on fetal bradyarrhythmia associated with congenital heart defects (CHD), we investigated its prognosis and risk factors. METHODS AND RESULTS: In our previous nationwide survey of fetal bradyarrhythmia from 2002 to 2008, 38 fetuses had associated CHD. Detailed clinical data were collected from secondary questionnaires on 29 fetuses from 18 institutions, and were analyzed. The 29 fetuses included 22 with isomerism, 4 with corrected transposition of the great arteries (TGA) and 3 with critical pulmonary stenosis; 14 had complete atrioventricular block (AVB), 8 had second-degree AVB, and 16 had sick sinus syndrome; 5 died before birth, and 10 died after birth (5 in the neonatal period). Neonatal and overall survival rates for fetal bradyarrhythmia with CHD were 66% and 48%, respectively. Pacemaker implantation was needed in 17 cases (89%). Beta-sympathomimetics were administered in utero in 13 cases and were effective in 6, but were not associated with prognosis. All cases of corrected TGA or ventricular rate ≥70 beats/min survived. A ventricular rate <55 beats/min had significant effects on fetal myocardial dysfunction (P=0.02) and fetal hydrops (P=0.04), resulting in high mortality. CONCLUSIONS: The prognosis of fetal bradyarrhythmia with CHD is still poor. The type of CHD, fetal myocardial dysfunction, and fetal hydrops were associated with a poor prognosis, depending on the ventricular rate.