Published papers

Interventions for gestational diabetes mellitus (GDM), diagnosed in early pregnancy, have been a topic of controversy. This study aimed to elucidate factors that predict patients with GDM diagnosed before 24 gestational weeks (early GDM: E-GDM) who require insulin therapy later during pregnancy. Furthermore, we identified patients whose impaired glucose tolerance should be strictly controlled from early gestation onward. Women diagnosed with GDM were categorized based on the gestational age at diagnosis into E-GDM (n = 388) or late GDM (L-GDM, diagnosed after 24 weeks, n = 340) groups. Clinical features were compared between the groups, and the predictors for insulin therapy was evaluated in the E-GDM group. There were no significant between-group differences in terms of perinatal outcomes (e.g., gestational weeks at delivery, fetal growth, hypertensive disorder of pregnancy), with the exception of the Apgar score at 5 min. Moreover, there was no significant difference in the frequency of insulin therapy during pregnancy between the two groups. Using multiple logistic regression analysis, pre-pregnancy body mass index (BMI) ≥25 kg/m2, a family history of diabetes, and higher fasting plasma glucose (FPG), 1 h-plasma glucose (PG), and 2 h-PG values increased insulin therapy risk during pregnancy in the E-GDM group. Furthermore, since E-GDM patients with abnormal levels of FPG, as well as 1 h-PG or 2 h-PG, and those with pre-pregnancy BMI ≥25 kg/m2 and a family history of diabetes had a higher risk of later insulin therapy during pregnancy, they may require more careful follow-up in the perinatal period.

Low-birthweight (LBW; <2,500 g) babies are at a higher risk of poor educational achievement, disability, and metabolic diseases than normal-birthweight babies in the future. However, reliable data on factors that contribute to LBW have not been considered previously. Therefore, we aimed to examine the distribution of the causes for LBW. A retrospective review of cases involving 4,224 babies whose mothers underwent perinatal care at Keio University Hospital between 2013 and 2019 was conducted. The LBW incidence was 24% (1,028 babies). Of the 1,028 LBW babies, 231 babies were from multiple pregnancies. Of the 797 singleton LBW babies, 518 (65%) were born preterm. Obstetric complications in women with preterm LBW babies included premature rupture of membrane or labor onset (31%), hypertensive disorders of pregnancy (HDP, 64%), fetal growth restriction (24%), non-reassuring fetal status (14%), and placental previa/vasa previa (8%). Of the 279 term LBW babies, 109 (39%) were small for gestational age. Multiple logistic regression analyses revealed the following factors as LBW risk factors in term neonates: low pre-pregnancy maternal weight, inadequate gestational weight gain, birth at 37 gestational weeks, HDP, anemia during pregnancy, female sex, and neonatal congenital anomalies. HDP was an LBW risk factor not only in preterm births but also in term births. Our results suggest that both modifiable and non-modifiable factors are causes for LBW. It may be appropriate to consider a heterogeneous rather than a simple classification of LBW and to evaluate future health risks based on contributing factors.

Low birth weight (LBW) is a significant concern not only because of its association with perinatal outcomes, but also because of its long-term impact on future health. Despite the physical differences among individuals of different ethnicities, the definition of LBW remains the same for all ethnicities. This study aimed to explore and discuss this issue. We compiled national data from several countries and found that maternal height was negatively correlated with LBW incidence. We discovered the INTERGROWTH-21st chart may not be suitable for the Japanese population, as the Japanese birth weight chart differs from the INTERGROWTH-21st chart. Researchers have reported different LBW cutoff values used to assess adverse perinatal outcomes for different countries. However, there is currently no definition of LBW independent of the mother’s country of origin that can be used for predicting the risk of adverse health outcomes. Therefore, the current era of personalized healthcare may be the perfect time to establish a standard definition of LBW which is independent of the mother’s country of origin. Considering the future of healthcare, it seems an apt time to discuss the development of a more meaningful definition of LBW that can be applied across ethnicities. Further research is needed to investigate the cutoff values of LBW in every ethnicity.

Managing RhD-negative pregnancies is vital for preventing hemolytic disease of the fetus and newborn, which occurs when RhD-negative mothers develop anti-D antibodies after exposure to RhD-positive fetal blood. This retrospective cohort study evaluated the proportion of RhD-negative pregnancies and newborns in Japan by assessing current management practices and outcomes. This study included RhD-negative pregnant women who delivered at 22 weeks or later at 47 Japanese facilities between April 2018 and March 2023. Pregnancies with unknown newborn RhD status were excluded. Data were obtained from medical records. Among the 1088 RhD-negative women, 1062 met the inclusion criteria. RhD-negative pregnancies comprised 0.71% of the total cohort, with 8.7% RhD-negative newborns. Anti-D immunoglobulin was administered in 96.5% of pregnancies, with a maternal spontaneous sensitization rate of 0.6% before 28 weeks and no sensitization detected from 28 weeks to postpartum. Sensitized RhD-negative women had higher cesarean section, preterm delivery, and neonatal hemolytic anemia rates than the non-sensitized group, leading to increased neonatal intensive care unit admissions. Despite the low incidence of RhD-negative pregnancies, this study underscores the need for tailored management strategies, suggesting that non-invasive prenatal diagnosis of fetal RhD status could prevent unnecessary anti-D immunoglobulin administration, improving outcomes and resource utilization in Japan.

© 2020 Royal College of Obstetricians and Gynaecologists Objective: Fetal fractional limb volume has been proposed as a useful measure for quantifying fetal soft tissue development. The aim of this study was to investigate the growth of fractional arm volume (AVol) and fractional thigh volume (TVol) of fetuses with maternal gestational diabetes (GDM) compared with those of fetuses with normal glucose tolerance (NGT). We hypothesised fetal fractional limb volume would be larger in the GDM group than in the NGT group in late gestation. Design: Exploratory observational study. Setting: Saitama Municipal Hospital. Sample: A total of 165 (125 NGT and 40 GDM) singleton Japanese pregnant women. Methods: AVol and TVol were assessed between 20 and 37 weeks’ gestation as cylindrical limb volumes based on 50% of the fetal humeral or femoral diaphysis length. Women were diagnosed as GDM based on the criteria of the Japan Society of Obstetrics and Gynecology. Main outcome measures: AVol and TVol were compared between women with NGT and those with GDM at each gestational age period (2-week intervals from 20 to 37 weeks’ gestation). Results: Overall, 287 ultrasound scans were performed (NGT group, 205 scans; GDM group, 82 scans). There was no significant difference of AVol between the groups before 32 weeks’ gestation. AVol was significantly larger in the GDM group than in the NGT group after 32 weeks’ gestation (P < 0.05). TVol was not statistically different between the groups across gestation. Conclusions: Detection of variations in fetal AVol may provide greater insight into understanding the origins of altered fetal body proportion in GDM. Tweetable abstract: AVol, but not TVol, is significantly larger in fetuses with GDM than in those with NGT after 32 weeks’ gestation.

© 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group. Background: No reports have focused on the clinical and metabolic characteristics of gestational diabetes (GDM) in underweight women. The aim of this study is to investigate the clinical and metabolic features of underweight GDM (pregravid BMI, <18.5 kg/m2: U-GDM). Materials and methods: Women diagnosed with GDM were categorized based on their pre-pregnancy BMI as either underweight (n = 49) or normal weight (pregravid BMI, 18.5–25.0 kg/m2: n = 271: N-GDM). During the study period, GDM was diagnosed using the International Association of Diabetes in Pregnancy Study Group criteria. Women with multi-fetal pregnancies, fetal congenital anomalies, overt diabetes in pregnancy, and pre-gestational diabetes mellitus were excluded. Results: There were no notable differences in maternal age at delivery and the rate of nulliparous between the U-GDM and N-GDM groups. Regarding antepartum oral glucose tolerance test profiles, women with U-GDM exhibited significantly lower fasting plasma glucose (FPG) levels than those with N-GDM (p <.01). The Insulinogenic Index of women with U-GDM was significantly lower than that of women with N-GDM (p <.05). Conclusion: Impaired early phase insulin secretion was associated with GDM onset in underweight women.

Introduction: Women who have undergone radical trachelectomy as a fertility-sparing treatment for early-stage cervical cancer may be at higher risk for retained tissues after early-term miscarriage due to cervical cerclage or cervical necrosis. Dilatation and curettage or aspiration may present additional risks in these women. The aim of this study was to assess the efficacy of expectant management for early pregnancy miscarriage after radical trachelectomy. Material and methods: Keio University Hospital records were reviewed for women who conceived after abdominal radical trachelectomy and received perinatal care between 1 April 2012 and 31 March 2020. A total of 62 women (76 pregnancies) were identified, and 13 of these women experienced miscarriage before 12 gestational weeks. The management and outcome of these cases were reviewed in detail. Results: The median maternal age at miscarriage was 39 years (range 31–42 years) and the median duration from abdominal radical trachelectomy to conception was 2.60 years (range 0.49–7.30 years). Cervical necrosis before conception occurred in one case (8%). One patient requested treatment with aspiration and the remaining 12 cases were managed with observation for a median of 23 days (range 7–50 days). There were no cases of endometritis or cases requiring dilatation and curettage for residue tissue. Further, no cases developed laceration of the residual cervix and no loss of cerclage sutures after discharge was noted. Conclusions: Expectant management seems to be safe and appropriate for first trimester miscarriage after abdominal radical trachelectomy.

Background and objectives: Massive postpartum hemorrhage (PPH) is the most common cause of maternal death worldwide. A massive transfusion protocol (MTP) may be used to provide significant benefits in the management of PPH; however, only a limited number of hospitals use MTP protocol to manage massive obstetric hemorrhages, especially in Japan. This study aimed to assess the clinical outcomes in patients in whom MTP was activated in our hospital. Materials and Methods: We retrospectively reviewed the etiology of PPH, transfusion outcomes, and laboratory findings among the patients treated with MTP after delivery in our hospital. Results: MTP was applied in 24 cases (0.7% of deliveries). Among them, MTP was activated within 2 h of delivery in 15 patients (62.5%). The median estimated blood loss was 5017 mL. Additional procedures to control bleeding were performed in 19 cases, including transarterial embolization (18 cases, 75%) and hysterectomy (1 case, 4.2%). The mean number of units of red blood cells, fresh frozen plasma, and platelets were 17.9, 20.2, and 20.4 units, respectively. The correlation coefficients of any two items among red blood cells, fresh frozen plasma, platelets, blood loss, and obstetrical disseminated intravascular coagulation score ranged from 0.757 to 0.892, indicating high levels of correlation coefficients. Although prothrombin time and activated partial thromboplastin time levels were significantly higher in the <150 mg/dL fibrinogen group than in the ≥150 mg/dL fibrinogen group at the onset of PPH, the amount of blood loss and blood transfusion were comparable between the two groups. Conclusions: Our MTP provides early access to blood products for patients experiencing severe PPH and could contribute to improving maternal outcomes after resuscitation in our hospital. Our study suggests the implementation of a hospital-specific MTP protocol to improve the supply and utilization of blood products to physicians managing major obstetric hemorrhage.

Objective: Pregnancy after conization is associated with a high risk of preterm delivery. However, because risk factors for preterm delivery after conization remain unknown, we conducted a multicenter observational study to investigate risk factors associated with preterm delivery. Methods: We selected patients who had previously undergone conization and reviewed medical records from 18 hospitals in cooperation with Keio University School of Medicine between January 2013 and December 2019. Women were classified as nulliparous and primiparous, and a multiple logistic regression analysis was performed to evaluate the relative contributions of the various maternal risk factors for preterm delivery (i.e. delivery before 37 gestational weeks). Results: Among 409 pregnant women after conization, 68 women delivered preterm (17%). The incidence of nulliparity (p =.014) was higher and a history of preterm delivery (p =.0010) was more common in the preterm delivery group than in the term delivery group. Furthermore, the proportion of women diagnosed with adenocarcinoma in situ (AIS) and cervical cancer in the preterm delivery group was higher than that in the term delivery group (p =.0099 and.0004, respectively). In multiple regression models in nulliparous women, cervical cancer or AIS (Odds ratio [OR]: 4.16, 95% CI: 1.26–13.68, p =.019) and a short cervix in the second trimester (OR: 13.41, 95% CI: 3.88–46.42, p <.0001) increased the risk of preterm delivery. Furthermore, a history of preterm delivery (OR: 7.35, 95% CI: 1.55–34.86, p =.012), cervical cancer or AIS (OR: 5.07, 95% CI: 1.24–20.73, p =.024), and a short cervix in the second trimester (OR: 4.29, 95% CI: 1.11–16.62, p =.035) increased the risk of preterm delivery in the multiple regression models in primiparous women. Conclusion: Pregnant women who previously underwent conization are at risk for preterm delivery. The histological type of AIS and cervical cancer was evaluated as a risk factor for preterm delivery. KEY MESSAGES Prior preterm delivery, presence of a short cervix, and cervical cancer or AIS were predictors of preterm delivery after conization. The depth of conization in cervical cancer or AIS group was significantly larger than that in the CIN group.

Preterm birth (PTB), defined as the birth of a baby at <37 weeks of gestation, is known to be the main cause of neonatal morbidity and mortality. Here, we report genetic associations between preterm birth and gestational age in a Japanese population. We conducted a genome-wide association study (GWAS) of 384 cases who delivered prematurely and 644 controls and considered gestational age as a quantitative trait in 1028 Japanese women. Unfortunately, we were unable to identify any significant variants associated with PTB or gestational age using the current sample. We also examined genetic associations previously reported in European populations and identified no associations, even with the genome-wide subthreshold (p value < 10–6). This data report aims to provide summary statistics of current GWASs on PTB in a Japanese population for future meta-analyses of genetics and PTB with larger sample sizes.

Aim: The induction of labor before due date has recently been proved to reduce the rate of cesarean sections and is not associated with increased risk of adverse perinatal outcomes as compared to expectant management. Controlled-release dinoprostone (PGE2) vaginal insert has recently been approved for use in Japan. However, evidence regarding its efficacy in cervical ripening and labor induction before due date remains limited. We aimed to compare the efficacy of PGE2 vaginal inserts and mechanical dilation for labor induction before due date. Methods: This retrospective cohort study included 206 mothers at 37, 38, and 39 weeks' gestation delivered at our institution between January 2021 and October 2022. Perinatal outcomes, including the success rate of vaginal delivery, were compared between the PGE2 (n = 46) and metreurynter/laminaria tent (non-PGE2) (n = 160) groups. The success rate of vaginal delivery was defined as the proportion of women who delivered vaginally within 48 h of initiating oxytocin augmentation. Results: The success rate of vaginal delivery was significantly higher in the PGE2 group (37/49, 80.4%) than in the non-PGE2 group (106/177, 66.2%). Emergency cesarean section related to non-reassuring fetal status was performed with none in the PGE2 group and with eight (5.0%) in the non-PGE2 group. Conclusions: The rate of vaginal delivery was significantly higher in the PGE2 group for elective labor induction between 37 and 39 weeks. The PGE2 vaginal insert could increase the success rate of vaginal delivery for elective induction of labor at 39 weeks.

25-hydroxyvitamin D (25(OH)D) regulates lipid metabolism, and its decrease is proposed as a pathogenesis of metabolic syndrome, gestational diabetes mellitus (GDM), and eventually fetal adiposity. Decreased 25(OH)D is also linked with the development of gestational diabetes mellitus (GDM), which is associated with increased fetal adiposity. Fetuses are dependent on the supply of 25(OH)D from maternal circulation. However, the influence of maternal serum 25(OH)D on fetal adiposity remains unclear. This study aimed to investigate the association between maternal serum 25(OH)D and fetal adiposity. A prospective longitudinal study was conducted in a cohort of 89 (including 21 GDM) singleton pregnancies. Maternal blood samples were obtained at 10, 24, 30, and 36 weeks, and fetal ultrasonography was performed at 24, 30, and 36 weeks of gestation. Estimated fetal adiposity (EFA) was calculated as the average z-score of cross-sectional arm and thigh percentage fat area and anterior abdominal wall thickness as previously reported. The multiple linear regression analyses indicated that maternal 25(OH)D levels across gestation were not associated with EFA at 24 and 30 weeks, while maternal 25(OH)D at 24 weeks was inversely correlated with EFA at 36 weeks. Particularly, in the GDM group, maternal 25(OH)D levels at 10, 24, 30, and 36 weeks all showed a significant negative correlation with EFA at 36 weeks. Decreased maternal serum 25(OH)D level could be an early biomarker of increased fetal adiposity in late gestation, especially in diabetic pregnancies.

Objective: We report a case of pregnancy following lung transplantation (LT) for idiopathic pulmonary arterial hypertension (IPAH) in Japan. Case Report: A female developed IPAH at 14 years of age and underwent a successful bilateral living-donor lobar LT from her parents at 19 years of age (gravida 2, para 0). At the age of 40 years, the patient became pregnant via artificial insemination. At 28 weeks of gestation, polyhydramnios and a fetal goiter were detected on transabdominal ultrasound. The patient was diagnosed with deep vein thrombosis and pulmonary embolism. The patient underwent emergency cesarean section to deliver a male neonate weighing 1340 g (−0.41SD) at 30 weeks of gestation, with an Apgar score of 5/5 (1/5 min). Conclusion: To our knowledge, this is the first reported case of a successful pregnancy following LT in Japan. Specialists should work together to manage pregnancies following LT.

Background/Objectives: Recently, it was reported that glucose variability (GV) calculated using the 75 g oral glucose tolerance test (OGTT) is associated with adverse perinatal outcomes. However, its role in gestational diabetes mellitus (GDM) remains unclear. We investigated the association between GV and insulin parameters in Japanese women diagnosed with GDM after 24 weeks of gestation (late GDM). Methods: A total of 280 mothers with late GDM cared for at Keio University Hospital were included in this study. Using 75 g OGTT, the initial increase and subsequent decrease were calculated as the GV. Results: The initial increase was significantly positively associated with 1 h plasma glucose level (PG) and 2 h PG with 75 g OGTT (p < 0.001), but fasting PG, insulinogenic index (IGI), and homeostasis model assessment—insulin resistance were negatively associated with the initial increase (all p < 0.001). The subsequent decrease was significantly positively correlated with 1 h PG (p < 0.001) but negatively correlated with 2 h PG (p < 0.001), IGI (p = 0.009), and the whole-body insulin sensitivity index derived from the OGTT (p = 0.02). Insulin Secretion-Sensitivity Index-2 was not associated with an initial increase or subsequent decrease. Conclusions: Since the initial increase might reflect insulin secretion and the subsequent decrease might reflect insulin sensitivity in Japanese women with late GDM, GV could alter several insulin parameters. Further studies are required to investigate the usefulness of GV in the management of GDM.

Birth weight is an important predictor of perinatal complications and long-term health outcomes of offspring. Fetal programming influenced by maternal obesity, overnutrition, and hyperglycemia has been proposed as the fuel overload hypothesis. Recent investigations related with fetal body composition have revealed that neonatal adiposity can be predicted by fetal fat mass, and that maternal insulin resistance and serum leptin level are indicators of fetal adiposity. Based on the current evidence, the origins of obesity can partly be traced back into the fetal life. Further clarification of the determinants of fetal fat mass may lead to the clinical interventions and treatment strategies for fetal growth and development. This effort potentially leads to the elucidation of pathological conditions related with long-term health outcomes and the primary prevention of childhood obesity and early onset metabolic syndrome.

Aims/Introduction: This study evaluated the risk factors for insulin therapy before 24 gestational weeks (early insulin therapy) in pregnant women with gestational diabetes diagnosed before 24 gestational weeks (E-GDM). Materials and Methods: This study included 530 singleton mothers with E-GDM who underwent a 75 g oral glucose tolerance test (OGTT) in the first trimester at Keio University Hospital between January 2013 and December 2021. E-GDM can be classified according to its management into only diet therapy until delivery (Diet E-GDM), insulin therapy started before 24 gestational weeks (EarlyIns E-GDM), and insulin therapy started after 24 gestational weeks (LateIns E-GDM). We analyzed the risk factors for EarlyIns E-GDM. Results: Patients with EarlyIns E-GDM had a significantly higher maternal age at delivery, pre-pregnancy BMI, first trimester hemoglobin A1c, 1 h plasma glucose levels (1 h-PG), and 2 h-PG, as well as a more pronounced initial increase and subsequent decrease, compared with those in the Diet E-GDM group. However, the Apgar scores at both 1 and 5 min were significantly lower in patients with EarlyIns E-GDM than in those with Diet E-GDM. The number of abnormal values in the OGTT showed the largest area under the receiver operating characteristic curve (AUC) for predicting EarlyIns E-GDM (0.83, 95% confidence interval [CI]: 0.79–0.86), followed by the 1 h-PG value (AUC: 0.81, 95% CI: 0.77–0.85). The initial increase showed the third largest AUC (0.78, 95% CI: 0.74–0.82). Conclusions: Although further research is needed, our data suggest the importance of early insulin therapy in cases of E-GDM with multiple abnormal OGTT values, especially with high 1 h-PG levels and initial increase.

Objective: This study aimed to investigate the obstetric outcomes of transabdominal cerclage (TAC) in Japan. Methods: Questionnaires on TAC were sent to 183 institutions performing high-quality perinatal management in Japan. As a first-step questionnaire, we asked whether TAC was performed between January 1, 2011, and December 31, 2022. In the second step of the questionnaire, the characteristics of all cases were asked from all institutions in which TAC was performed. Results: The response rate for the first survey was 59% (108/183). Of the 108 institutions, 27 performed TAC (25%) in 133 pregnancies. Of these 27 institutions, 19 responded to the second survey. One hundred twenty-five pregnancies were included in this study, five of which were aborted (gestational weeks <22 weeks), and 69 babies were born after 37 gestational weeks (55%). Eighty-two open abdominal cerclages were performed at 17 institutions and 43 laparoscopic TACs at three institutions. There were no differences in the age at TAC, gestational weeks at TAC, operative time of TAC, gestational weeks at delivery, incidence rate of second-trimester loss, or preterm delivery (before 37 gestational weeks) rate between the two groups. However, blood loss during open TAC was greater than that during laparoscopic TAC. Conclusion: TAC is a rare surgery for cervical insufficiency in Japan. TAC may be a safe and useful method for preventing second-trimester loss and preterm delivery in high-risk patients. TAC may also be a key option in Japan to improve perinatal outcomes in patients with cervical insufficiency.

目的:コロナ禍で妊娠糖尿病(gestational diabetes mellitus:GDM)診断がどのように変化したかを明らかにする。方法:全国の分娩取り扱い施設(2159施設)に対し、コロナ禍でのGDM診断方法の変化について調査した(回答率27%)。結果:妊娠24週未満/以降GDMともに90%前後の施設が診断方法を変更しなかった。一方、妊娠24週未満では19施設、24週以降では17施設が75g経口糖負荷試験を中止し、日本糖尿病・妊娠学会による「妊娠中の糖代謝異常のスクリーニング～COVID-19パンデミック対応～」を使用した。結論:今後のさらなる非常時に備え、有用な簡易型診断基準を作成するため、リスク因子抽出などの検討が必要であると考えられた。(著者抄録)