Impact of changes in recommendation of optimal gestational weight gain in Japan: A retrospective study in a single tertiary center.

AIM: In March 2021, the Japanese Ministry of Health, Labour and Welfare revised the optimal gestational weight gain standards. In this study, we examined whether this revision affected gestational weight gain and low birth weight rates. METHODS: We analyzed the records of singleton pregnant women who underwent checkups from their 1st trimester and delivered at our institute after 37 weeks between 2020 and 2021 (before the revision) and between 2022 and 2023 (after the revision). Pregnancy outcomes were assessed in the following four groups stratified by pre-pregnancy body mass index (BMI): underweight (BMI: <18.5 kg/m2), normal-weight (BMI: 18.5-24.9 kg/m2), overweight (BMI: 25-29.9 kg/m2), and obese (BMI: ≥30 kg/m2). Leaflets on the optimal gestational weight gain standards for each group were distributed to all pregnant women at the first prenatal checkup. RESULTS: In each group, gestational weight gain did not change before and after the revision, with the corresponding values of 10.8 kg and 11.1 kg in the underweight (p = 0.94), 10.7 kg and 10.4 kg in the normal weight (p = 0.14), 9.7 kg and 9.2 kg in the overweight (p = 0.32), and 7.4 kg and 6.7 kg in the obese (p = 0.44) groups. Furthermore, the prevalence of low birth weight did not decrease in all groups. CONCLUSIONS: No significant differences in gestational weight gain or low birth weight were observed after the revision of the 2021 gestational weight gain recommendations. Merely distributing leaflets to pregnant women may not be sufficient to improve gestational weight gain or reduce low birth weight rates.

Impact of Introducing a Controlled-Release Dinoprostone Vaginal Insert for Labor Induction: A Retrospective Single-Center Study in Japan.

AIM: Cervical ripening is commonly performed before oxytocin administration during labor induction in pregnant women with an unfavorable cervix. In Japan, a controlled-release Dinoprostone vaginal insert (CR-DVI) was approved in 2020. Although many studies have compared the mechanical methods of ripening and prostaglandins, few have examined the impact of additional options for labor induction. This study aimed to assess the impact of CR-DVI as an additional option for labor induction in women with an unfavorable cervix. METHODS: In this single-center retrospective study conducted in Japan, 265 participants were divided into two groups: before (January 2018 to May 2020) and after (June 2020 to November 2022) CR-DVI introduction. Before CR-DVI was introduced, hygroscopic dilators were used for all cases instead. On the other hand, after the introduction of CR-DVI, the first choice for cervical ripening was CR-DVI. The CR-DVI was retained vaginally for up to 12 hours after insertion. However, if hyper-stimulation or non-reassuring fetal status was suspected, or if a new membrane rupture occurred, it was removed immediately according to the removal criteria. Oxytocin infusions were used during both periods if needed. We compared delivery and neonatal outcomes between the groups. RESULTS: The 265 participants were divided into two groups: before (n=116) and after (n=149) CR-DVI introduction. There were no significant differences in maternal characteristics except for the primiparous proportion. CR-DVI was used in 93% of cases after introduction. Hygroscopic dilators also continued to be used; however, their use decreased to about 34%. The vaginal delivery rate was significantly higher after the introduction of CR-DVI than before its introduction (50.9% vs. 66.4%; p=0.01). Multivariable analysis revealed a significantly higher rate of vaginal delivery after CR-DVI introduction. Of the 149 cases in which a CR-DVI was used, 111 (79.9%) were removed before 12 hours. There were no significant differences in neonatal outcomes. CONCLUSION: The rate of vaginal delivery was higher after CR-DVI introduction than before its introduction, and adverse pregnancy outcomes did not increase. Therefore, introducing CR-DVI as an option for labor induction may increase the probability of vaginal delivery. Safety can also be ensured by adhering to the removal criteria.

A deletion variant in LMX1B causing nail-patella syndrome in Japanese twins.

Nail-patella syndrome (NPS) is a hereditary disease caused by pathogenic variants in LMX1B and characterized by nail, limb, and renal symptoms. This study revealed a likely pathogenic LMX1B variant, NM_002316.4: c.723_726delinsC (p.Ser242del), in Japanese twins with clubfoot. The patients' mother, who shared this variant, developed proteinuria after delivery. p.Ser242del is located in the homeodomain of the protein, in which variants that cause renal disease tend to cluster. Our findings highlight p.Ser242del as a likely pathogenic variant, expanding our knowledge of NPS.

Difficulty in Serologic Screening for Subclinical Rubella during Pregnancy.

In Japan, rubella antibodies are tested in all pregnant women to detect subclinical infections. This study aimed to assess the validity of measuring rubella antibodies for detecting subclinical rubella among pregnant women in Japan. This single-center retrospective study measured rubella hemagglutination inhibition (HI) titers and rubella-specific IgM antibody index (IgM) values. IgM values were measured by conducting enzyme immunoassay, and IgM-values >1.2 were considered positive. Of 14,965 included pregnant women, 186 (1.2%) were IgM-positive. Only one patient was clinically diagnosed with rubella (HI titer, 1:2,048; IgM value, 10) and developed fever and skin rash. She decided to terminate her pregnancy without undergoing repeated blood tests. Of the IgM-positive patients, 136 (73.1%) had rubella HI titers of < 1:256. The correlation coefficient between rubella HI and IgM titers was weakly positive (0.2527; P < 0.0001). This study showed that a single combination of rubella HI and rubella-specific IgM measurements alone could not detect subclinical rubella. Creating awareness among pregnant women by informing them that almost all rubella-specific IgM-positive individuals without symptoms are not acutely infected could decrease their anxiety and prevent unnecessary pregnancy termination.

Women with elevated blood pressure and stage 1 hypertension are at high risk for preeclampsia. A retrospective study at a tertiary facility in Japan.

AIM: In 2017, the American College of Cardiology (ACC) re-defined hypertension (HT) as follows: elevated blood pressure (EBP), systolic blood pressure (SBP) 120-129 mmHg and diastolic blood pressure (DBP) <80 mmHg; stage 1 HT, SBP 130-139 mmHg or DBP 80-89 mmHg; and stage 2 HT: SBP ≥140 mmHg or DBP ≥90 mmHg. It is well known that women with stage 2 HT are at higher risk of preeclampsia and have poorer pregnancy and delivery outcomes. While there are few reports on the risk in women with EBP and stage 1 HT, and none from Japan. This study aimed to determine whether women in Japan with EBP and stage 1 HT are at risk of preeclampsia. METHODS: In this single-center retrospective study conducted in Japan, subjects were classified into stage 2 HT, stage 1 HT, EBP, and normal groups based on blood pressure measurements at the time of the first visit before 20 weeks of gestation. Women with a diagnosis of hypertension made before pregnancy were classified into the stage 2 HT group. We compared pregnancy and delivery outcomes, such as preeclampsia, between groups. RESULTS: A total of 5129 cases (normal, n = 4283; EBP, n = 427; stage 1 HT, n = 303; stage 2 HT, n = 116) were included. Preeclampsia incidence rates were 2.7%, 5.6%, 10.6%, and 21.6%, respectively. The adjusted OR (95% CI) for preeclampsia incidence were 2.90 (1.81-4.66), 5.90 (3.87-9.20), and 13.80 (7.97-24.0), respectively. CONCLUSIONS: Women with EBP and stage 1 HT are at high risk of preeclampsia, similar to those with stage 2 HT.

Non-efficacy of early intervention strategy for non-obese patients with early-onset gestational diabetes mellitus: solely based on the short-term outcomes.

INTRODUCTION: To verify the effectiveness of intervention in early pregnancy for women with early-onset gestational diabetes mellitus (GDM). RESEARCH DESIGN AND METHODS: This study included women with a singleton pregnancy who were diagnosed with early-onset GDM by 20 weeks of gestation according to the International Association of Diabetes and Pregnancy Study Group (IADPSG) threshold. We retrospectively evaluated the pregnancy outcomes in pregnant women with early-onset GDM. In the treatment from early pregnancy group (n=286), patients were diagnosed with early-onset GDM at the Yokohama City University Medical Center (YCU-MC) in 2015-2017 and were treated for GDM from early pregnancy. Concerning the treatment from mid-pregnancy group (n=248), participants were diagnosed with early-onset GDM at five sites, including the YCU-MC in 2018-2019, and were followed up without treatment until the second 75 g oral glucose tolerance test (OGTT) at 24-28 weeks of gestation. Treatment for GDM was given only if the GDM pattern was still present in the second OGTT. RESULTS: There were no significant differences in maternal backgrounds, including GDM risk factors and gestational weight gain, between the groups. Among the treatment from mid-pregnancy group, the false-positive early GDM was 124/248 (50%). Regarding pregnancy outcome, the rate of large for gestational age (LGA) was 8.8% in the treatment from early pregnancy group and 10% in the treatment from mid-pregnancy group, with no significant difference, whereas small for gestational age (SGA) was significantly higher in the treatment from early pregnancy group (9.4%) than in the treatment from mid-pregnancy group (4.8%) (p=0.046). There were no significant differences in maternal adverse events and neonatal outcomes between the groups. In a subanalysis limited to body mass index >25 kg/m2, LGA was significantly lower in the treatment from early pregnancy group than in the treatment from mid-pregnancy group. CONCLUSIONS: The strategy for diagnosing GDM by IADPSG thresholds in early pregnancy and providing treatment to all patients from early pregnancy did not improve the pregnancy outcomes, but rather increased the SGA rate.

Successful fertility preservation by expectant management of a cervico-isthmic pregnancy with fetal death in the second trimester: A case report.

In a cervico-isthmic pregnancy, the risk of placenta accreta increases with advancing gestational age. Previous reports have detailed cases that required hysterectomy at delivery or artificial abortion at an early gestational age. However, to the best of our knowledge, there have been no previous reports on the management of a cervico-isthmic pregnancy with fetal death during the second trimester. A 33-year-old primigravid woman was diagnosed with a cervico-isthmic pregnancy and fetal death at 15 weeks of gestation. Placenta accreta was suspected; hence, we chose expectant management and to observe the patient for placental tissue regression. After 5 weeks of expectant management, the ultrasonographic findings suggested remission of placenta accreta. Therefore, we performed a cesarean delivery and terminated the pregnancy. All uterine contents were removed, and the uterus was preserved. In cervico-isthmic pregnancy cases with fetal death, as in the current case, the possibility of fertility preservation could be increased by observing for placental tissue regression through expectant management.

Do pregnancy outcomes of women with false-positive early gestational diabetes mellitus differ from those of women with normal glucose tolerance?

BACKGROUND: To investigate whether false-positive early gestational diabetes mellitus (GDM) women can be managed similarly as normal glucose tolerance (NGT) women. METHODS: This retrospective study was conducted at a tertiary care center in Japan. Pregnancy and neonatal outcomes of 67 singleton pregnancies with false-positive early GDM and 1774 singleton pregnancies with NGT who delivered after 22 weeks of gestation were compared. GDM was diagnosed according to the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria (patients having one or more of the following: fasting plasma glucose ≥ 92 mg/dL and a 75 g oral glucose tolerance test (OGTT) value ≥ 180 mg/dL at 1 h, or ≥ 153 mg/dL at 2 h). Pregnant women diagnosed with GDM in early pregnancy who did not meet the diagnostic criteria on the second OGTT were defined as having false-positive early GDM. Women with false-positive early GDM did not receive any therapeutic intervention during gestation. RESULTS: Maternal age, pre-pregnancy body mass index, and gestational weight gain were significantly higher in the false-positive GDM group than in the NGT group. No significant differences were found in pregnancy outcomes, including gestational age, birth weight, large for gestational age rate, and cesarean delivery rate. Except for a higher neonatal hypoglycemia rate in the false-positive early GDM group, no significant differences were found in neonatal outcomes. CONCLUSIONS: There were no clinically significant differences between early GDM false-positive women exhibiting GDM patterns only during early pregnancy and NGT women. False-positive early GDM women can be managed similarly as NGT women, suggesting that World Health Organization diagnostic guidelines, applying the IADPSG criteria during early pregnancy, need revision.

An extremely prolonged second stage of labor increases maternal complications but has no adverse effect on neonatal outcomes.

AIM: To investigate how an extremely prolonged second stage of labor of 12 h or more affects maternal and neonatal outcomes. MATERIAL AND METHODS: This retrospective cohort study included nulliparous, pregnant women with 37 + 0 to 41 + 6 weeks of gestation whom vaginal delivery was attempted at the Yokohama City University Medical Center between 2014 and 2018. RESULTS: In 446 cases of the prolonged second stage of labor, there were 296 women (66%) in the 2- to 6-h second stage of labor group, 112 women (25%) in the 6- to 12-h group, and 38 women (8.5%) in the 12-h or longer group. The longer the second stage of labor, the more significant was the increase in the rates of augmentation of the delivery, emergency cesarean delivery, and operative vaginal delivery. Even in the 12 h or longer group, 82% were able to have vaginal delivery. The 6- to 12-h group had a significant increase in third- or fourth-degree perineal lacerations compared to the 2- to 6-h group (aOR 8.12 [95% CI 1.55-42.6]). Clinical chorioamnionitis was significantly increased in the 12 h or longer group (aOR 4.88 [95% CI 1.62-14.8]). In terms of neonatal outcomes, comparison between the three groups showed no significant difference. CONCLUSION: With an extremely prolonged second stage of labor, maternal complications involved a significant increase in severe perineal lacerations and chorioamnionitis; however, there was no increase in adverse outcomes for neonates. It was not possible to conclusively determine if the duration of the second stage is acceptable.

Spontaneous labor curve based on a retrospective multi-center study in Japan.

AIM: In Japan, the criteria of the latent and active phases of the first stage of labor have not been decided. The Japan Society of Obstetrics and Gynecology (JSOG) Perinatal Committee conducted a study to construct a spontaneous labor curve in order to determine the point of onset of the active phase. METHODS: The participants were women who had spontaneous deliveries at four health facilities in Japan between September 1, 2011, and September 31, 2019. Spontaneous delivery was defined as the spontaneous onset of labor at term (37 weeks, 0 days to 41 weeks, 6 days) with vaginal delivery of a mature fetus in a cephalic position without uterotonic agents or epidural analgesia. The time points for each "cm" of dilation were collected starting from the time of full dilation retrogradely. The relationship between time since labor onset and cervical dilation was expressed as a curve using a smoothing B-spline. RESULTS: A total of 4215 primiparous and 5266 multiparous women were included in this study. The spontaneous labor curve showed that in both primiparous and multiparous women, labor progress was slow until 5 cm cervical dilation, accelerating between 5 and 6 cm dilation, and steadily progressed after 6 cm dilation. CONCLUSION: We propose that the active phase of the first stage of labor be defined as starting at 5 cm dilation of the cervix, and that it be divided into an acceleration phase (5-6 cm dilation) and a maximal phase (>6 cm dilation).

Weight gain during twin pregnancy with favorable pregnancy outcomes in Japan: A retrospective investigation for new criteria based on perinatal registry data.

In 2009, the United States Institute of Medicine (IOM) reported the optimal gestational weight gain (GWG) during twin pregnancy based on the pre-pregnancy body mass index (BMI). However, there are ethnic variations in the relationship between GWG and pregnancy outcomes. We aimed to establish the criteria for optimal GWG during twin pregnancy in Japan. The study included cases of dichorionic diamniotic twin pregnancy registered in the Japan Society of Obstetrics and Gynecology Successive Pregnancy Birth Registry System between 2013 and 2017. We analyzed data for cases wherein both babies were appropriate for gestational age and delivered at term. Cases were classified into four groups based on the pre-pregnancy BMI: underweight (BMI <18.5 kg/m2), normal weight (18.5 kg/m2 ≤BMI< 25.0 kg/m2), overweight (25.0 kg/m2 ≤BMI< 30.0 kg/m2), and obese (BMI ≥30.0 kg/m2) and we calculated the 25th-75th percentile range for GWG for the cases. The 3,936 cases were included. The GWG ranges were 11.5-16.5 kg, 10.3-16.0 kg, 6.9-14.7 kg, and 2.2-11.7 kg in the underweight, normal weight, overweight, and obese groups, respectively. Thus, in the current study, the optimal GWG during twin pregnancy was lower than that specified by the IOM criteria. Factoring this in maternal management may improve the outcomes of twin pregnancies in Japan.

Effect of interventions in pregnant women with mildly impaired glucose tolerance.

AIM: In 2010, the Japan Society of Obstetrics and Gynecology (JSOG) changed the diagnostic criteria for gestational diabetes mellitus (GDM) to follow the International Association of Diabetes and Pregnancy Study Group (IADPSG) criteria. As a result, many pregnant women with mildly impaired glucose tolerance (IGT) were newly diagnosed with GDM. This study aimed to verify the effects of interventions in pregnant women with mild IGT who were newly diagnosed with GDM based on the present JSOG criteria. METHODS: We defined mild IGT as a degree of IGT that would be diagnosed as GDM according to the present but not the previous JSOG criteria. We compared pregnancy and delivery outcomes in women with mild IGT who delivered a singleton at 22 weeks of gestation or later, between 2000 and 2009 (untreated group, n = 503) versus between 2011 and 2017 (treated group, n = 781). RESULTS: The incidence of GDM-related composite complications such as macrosomia, shoulder dystocia, neonatal hypoglycemia, neonatal hyperbilirubinemia, and neonatal respiratory distress syndrome was comparable in the untreated and treated groups (10.1% vs. 11.9%, p = 0.11). The pregnancy outcomes were also comparable, except for infant birth weights, which were lower in the treated group than in the untreated group (3014 g vs. 3094 g; p = 0.02). CONCLUSIONS: Pregnancy outcomes were not affected by the interventions in pregnant women with mild IGT.

Impact of gestational diabetes mellitus diagnosed during the third trimester on pregnancy outcomes: a case-control study.

BACKGROUND: In 2010, the International Association of Diabetes and Pregnancy Study Group (IADPSG) proposed new criteria indicating that gestational diabetes mellitus (GDM) can be diagnosed if the fasting threshold of ≤92 mg/dL, 1-h threshold of ≤180 mg/dL, or 2-h threshold of ≤153 mg/dL are exceeded during the 75-g 2-h oral glucose tolerance test (OGTT) performed at 24-28 weeks of gestation. The World Health Organization (WHO) recommends using the proposed diagnostic threshold values of the IADPSG to diagnose GDM; however, it does not limit the timing of the 75-g OGTT. Since 2010 in Japan, GDM has been diagnosed using the same criteria as that proposed by the WHO. However, neither the JSOG nor the WHO has provided any evidence that it is appropriate to use a threshold beyond the range recommended by the IADPSG. METHODS: This was a single-centre retrospective study based on the medical records and delivery registry database of our centre. We included women who underwent a 50-g glucose challenge test (GCT) with results < 140 mg/dL at 24-28 weeks of gestation and subsequently underwent a 75-g OGTT after 29 weeks of gestation with abnormal glucose tolerance suspected based on clinical findings. The reference values for the 75-g OGTT followed the IADPSG criteria. Subjects were classified into the normal glucose tolerance (NGT) group and the GDM group. The type of delivery and neonatal outcomes of the two groups were compared. A multivariable analysis was performed to match the backgrounds of both groups. RESULTS: In total, the NGT and GDM group comprised 189 and 49 women, respectively. Emergency caesarean delivery rates were similar in the GDM and NGT groups (10.6 and 12.2%, respectively; adjusted odds ratio [OR], 1.25; 95% confidence interval [CI], 0.43-3.64; p = 0.74); however, the elective caesarean delivery rate was higher in the GDM group than in the NGT group (16.3 and 5.3%, respectively, adjusted OR, 3.60; 95% CI, 1.27-10.19; p = 0.01). No significant differences were observed in other maternal and neonatal outcomes between both groups. CONCLUSION: Although a diagnosis of GDM during the third trimester does not improve pregnancy outcomes, it increases the elective caesarean delivery rate.

Perinatal outcomes of recurrent placental abruption.

INTRODUCTION: The purpose of this study was to classify patients with placental abruption (PA) into those with a history of PA (recurrence group) and those without a history (first-occurrence group), and compare the two groups to investigate whether perinatal outcomes differ between first-time PA and recurrent PA. MATERIALS AND METHODS: Subjects include 6475 patients diagnosed with PA from the Pregnancy Birth Registry System of the Japan Society of Obstetrics and Gynecology. Patients were classified into recurrence group and first-occurrence group. Perinatal outcomes were compared between 141 patients in the recurrence group and 705 patients in the first-occurrence group with 1:5 propensity score matching, adjusting for maternal age, history of smoking, pregnancy-induced hypertension, and premature rupture of membranes as covariates. RESULTS: There were no cases of maternal mortality in either groups, and the perinatal mortality rate did not exhibit a significant difference. Gestational age at delivery was significantly earlier in the recurrence group than in the first-occurrence group (35.3 vs 37.9 weeks, p < .001). The rate of preterm delivery at less than both 32 and 37 weeks of gestation was significantly higher in the recurrence group. The rate of UmApH < 7.1 and 5 min Apgar score < 7 were significantly higher in the recurrence group (21 vs 13%, p = .020, 20% vs 10%, p = .003, respectively). CONCLUSIONS: The results suggest that recurrent PA occurs at an earlier gestational age and follows a more severe course than the first occurrence of PA.

High probability of false-positive gestational diabetes mellitus diagnosis during early pregnancy.

INTRODUCTION: This study aimed to assess the validity of applying the International Association of Diabetes and Pregnancy Study Group (IADPSG) criteria for the diagnosis of gestational diabetes mellitus (GDM) at any time during pregnancy. RESEARCH DESIGN AND METHODS: This multicenter cohort study was conducted at five Japanese facilities from January 2018 to April 2019. The study cohort included women at a high risk of GDM who met one or more of the following IADPSG criteria during early pregnancy: fasting plasma glucose (FPG) ≥92 mg/dL and 75 g oral glucose tolerance test (OGTT) value of ≥180 mg/dL at 1 hour, or ≥153 mg/dL at 2 hour (hereafter early-onset GDM). Women diagnosed with early-onset GDM were followed up without therapeutic intervention and underwent the 75 g OGTT again during 24-28 weeks of gestation. Those exhibiting the GDM patterns on the second 75 g OGTT were diagnosed with true GDM and treated, whereas those exhibiting the normal patterns were diagnosed with false positive early GDM and received no therapeutic intervention. RESULTS: Of the 146 women diagnosed with early-onset GDM, 69 (47%) had normal 75 g OGTT values at 24-28 weeks of gestation, indicating a false-positive result. FPG levels were significantly higher in the first 75 g-OGTT test than in the second 75 g-OGTT test (93 mg/dL and 87.5 mg/dL, respectively; p<0.001). FPG levels were high in 86 (59%) women with early-onset GDM during early pregnancy but in only 39 (27%) women during mid-pregnancy. Compared with false positive early GDM, true GDM was more frequently associated with adverse pregnancy outcomes. CONCLUSIONS: Although women with early-onset GDM were followed up without treatment, the results of repeated 75 g OGTT during mid-pregnancy were normal in about 50%. Our data did not support the adoption of IADPSG thresholds for the diagnosis of GDM prior to 20 weeks of gestation.

Current situation and outcomes of pregnancy in women with Turner syndrome in Japan.

AIM: Reports on pregnancy and delivery in women with Turner syndrome (TS) in Japan are limited to case reports, and the current situation remains unclear. Therefore, this study aimed to clarify the current situation of pregnancy and delivery in women with TS in Japan. METHODS: Our study comprised primary and secondary surveys and we included perinatal centers approved by the Ministry of Health, Labor and Welfare. RESULTS: A total of 24 cases from 19 facilities were reported, and we obtained individual information for 20 cases from 16 facilities. Of these 20 patients, 13 (65%) had become pregnant via oocyte donation. Three of these patients had received oocyte donation in Japan, while the other 10 had received donations in foreign countries. The other seven patients became pregnant with their own oocyte, with spontaneous menarche. Live babies were delivered by 18 patients, while an induced abortion was required at 18 weeks of gestation in one patient and an intrauterine fetal death from an unknown cause was detected at 38 weeks of gestation in another patient. Cesarean section was performed in 14 patients, with the most frequent indication being cephalopelvic disproportion. The rate of implementation of screening for complications related to TS was low, suggesting insufficient cooperation between facilities responsible for TS treatment, infertility and pregnancy and delivery management. CONCLUSION: To improve pregnancy outcomes in women with TS, improved cooperation between facilities and laws regarding oocyte donation in Japan are needed.

Have pregnancy outcomes improved with the introduction of the International Association of Diabetes and Pregnancy Study Groups criteria in Japan?

AIMS/INTRODUCTION: This study aimed to investigate the effects of the introduction of the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria for diagnosing gestational diabetes mellitus (GDM) on maternal and neonatal outcomes in Japan. MATERIALS AND METHODS: This was a retrospective study carried out at a tertiary center in Japan. Previously in Japan, GDM was diagnosed if two or more of the following Japan Society of Obstetrics and Gynecology (JSOG) criteria were met: fasting plasma glucose ≥100 mg/dL, 1-h value ≥180 mg/dL or 2-h value ≥150 mg/dL on the 75-g oral glucose tolerance. Since 2010, GDM has been diagnosed if one or more of the following IADPSG criteria are met: fasting plasma glucose ≥92 mg/dL, 1-h value ≥180 mg/dL or 2-h value ≥153 mg/dL on the 75-g oral glucose tolerance. We compared the pregnancy outcomes of all pregnant women with singleton pregnancies after 22 weeks' gestation at our hospital before (JSOG period) and after (IADPSG period) the IADPSG criteria were adopted. RESULTS: There were 3,912 women in the JSOG period and 4,772 in the IADPSG period. GDM prevalence increased from 2.9% in the JSOG period to 13% in the IADPSG period (P < 0.001). No significant differences between the groups were found in rates of macrosomia, or large for gestational age, and no significant differences were found in birthweight. The neonatal hypoglycemia rate and neonatal intensive care unit admission rate were significantly lower in the IADPSG period (adjusted odds ratio 0.51 and 0.78, respectively). CONCLUSIONS: Introduction of the IADPSG criteria for diagnosing GDM increased GDM diagnosis frequency fourfold, but reduced neonatal intensive care unit admission and neonatal hypoglycemia rates significantly.

Risk Factors for Chlamydia trachomatis Infection and Preterm Birth in Pregnant Japanese Women: Does Chlamydial Infection Cause Preterm Birth?

The aim of this study was to clarify the risk factors for chlamydial infection and determine whether infection during pregnancy is associated with preterm birth in Japanese women. The subjects were women who underwent Chlamydia trachomatis polymerase chain reaction testing during a singleton pregnancy and delivered after the 22nd week of gestation at a tertiary care center between January 1, 2000 and December 31, 2016. We compared Chlamydia-positive (n = 259) and Chlamydianegative (n = 1,974) groups and evaluated the pregnancy outcomes. The Chlamydia-positive group had a higher rate of public assistance coverage, smoking during pregnancy, nulliparity, lack of a partner, presence of other sexually transmitted infections, high-risk social status, and younger age (P < 0.01). The incidence of preterm births was not different between the groups, with an odds ratio of 0.95 (95% confidence interval: 0.62-1.46). The incidences of low birth weight deliveries, premature rupture of membranes, and preterm premature rupture of membranes prior to the 37th week were also comparable between the groups. Chlamydial infection during pregnancy had no effect on preterm birth, even after adjustment for confounding factors.

Impact of introducing the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria on pregnancy outcomes in Japan.

To estimate pregnancy complications in women newly diagnosed with gestational diabetes mellitus (GDM) according to the new International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria and verify the validity of introducing the IADPSG criteria in Japan. This retrospective study included data from women with singleton delivery at 22 weeks or later at a tertiary hospital during 2000-2009. We compared pregnancy outcomes between women who would now be diagnosed with GDM according to the IADPSG criteria but not by the old JSOG criteria (IGT group, n = 503) and women with normal glucose tolerance according to both the criteria (NGT group, n = 2,789). Multivariate analysis was performed and adjusted for background factors. Maternal age at delivery and pre-pregnancy BMI were significantly higher in the IGT group than in the NGT group, while gestational weeks at delivery did not differ between the groups. No difference was observed in the rates of GDM-related composite complications (defined as cases with at least one of the following: macrosomia, shoulder dystocia, neonatal hypoglycemia, neonatal hyperbilirubinemia, or neonatal respiratory distress syndrome) at 11.9% and 8.8% (adjusted odds ratio (OR) 1.30, 95% confidence interval (CI) 0.90-1.87, p = 0.16). Pregnancy outcomes did not differ significantly between the IGT and NGT groups, except for frequencies of total neonatal admissions at 10.5% and 7.1%, respectively (adjusted OR 1.55, 95% CI 1.12-2.13, p < 0.01).

Optimal gestational weight gain for underweight pregnant women in Japan.

We aimed to investigate the optimal range of gestational weight gain (GWG) for Japanese underweight (body mass index <18.5 kg/m2) women using the Japanese Birth Registry System. The study subjects included underweight women who were divided into groups according to the GWG recommendations of the Ministry of Health, Labour and Welfare (MHLW) (9-12 kg): <9.0 kg, group A; 9-12 kg, group B; and >12 kg, group C. The subjects were then classified according to the recommendations of the Institute of Medicine (IOM) (12.7-18.1 kg): <12.7 kg, group D; 12.7-18.1 kg, group E; and >18.1 kg, group F. In total, 148,135 cases were analysed. The frequencies of small for gestational age, preterm delivery, and caesarean delivery were as follows: 19.3%, 22.7%, and 28.5% for group A; 11.7%, 8.7%, and 22.8% for group B; 8.0%, 4.9%, and 21.5% for group C; 15.0%, 14.7%, and 25.2% for group D; 8.0%, 5.3%, and 21.5% for group E; and 7.0%, 5.5%, and 25.0% for group F, respectively. These results indicated that groups C and E had the best outcomes. Therefore, the IOM guidelines seem more appropriate than the MHLW guidelines. Therefore, the MHLW recommended GWG guidelines require revision.