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Objectives: This study aimed to evaluate the association between atopic dermatitis in pregnant women and preterm births, accounting for maternal ritodrine hydrochloride administration status., Methods: Data of 83,796 women with singleton pregnancies at and after 22 weeks of gestation (enrolled between 2011 and 2014) were analyzed. These data were obtained from the Japan Environment and Children's Study. Atopic dermatitis was defined based on self-reported questionnaire responses obtained during the first trimester. The primary outcome measures were preterm births before 37, 32, and 28 weeks of gestation. Using a multivariable logistic regression model, odds ratios for preterm births in pregnant women with atopic dermatitis were calculated, with women without atopic dermatitis included in the reference group. This analysis considered confounding factors and maternal ritodrine hydrochloride administration., Results: Among pregnant women with atopic dermatitis, the adjusted odds ratios (95% confidence intervals) for preterm births before 37, 32, and 28 weeks of gestation were 0.89 (0.81-0.98), 0.98 (0.74-1.30), and 0.88 (0.50-1.55), respectively. This trend remained consistent after excluding participants who received ritodrine hydrochloride., Conclusions for Practice: Atopic dermatitis in pregnant women was significantly associated with a decreased incidence of preterm births before 37 weeks of gestation, even after accounting for the effects of maternal ritodrine hydrochloride administration., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Preterm birth (PTB) is a leading cause of neonatal morbidity and mortality. Therefore, this study aimed to determine whether preconception dietary fiber intake is associated with PTB. This was a prospective cohort Japan Environmental and Children's Study (JECS). The study population comprised 85,116 singleton live-birth pregnancies from the JECS database delivered between 2011 and 2014. The participants were categorized into five groups based on their preconception dietary fiber intake quintiles (Q1 and Q5 were the lowest and highest groups, respectively). Multiple logistic regression analysis was performed to determine the association between preconception dietary fiber intake and PTB. Multiple logistic regression analysis revealed that the risk for PTB before 34 weeks was lower in the Q3, Q4, and Q5 groups than in the Q1 group (Q3: adjusted odds ratio [aOR] 0.78, 95% confidence interval [CI] 0.62-0.997; Q4: aOR 0.74, 95% CI 0.57-0.95; Q5: aOR 0.68, 95% CI 0.50-0.92). However, there was no significant difference between preconception dietary fiber intake and PTB before 37 weeks. In conclusion, higher preconception dietary fiber intake correlated with a reduced the risk for PTB before 34 weeks. Therefore, new recommendations on dietary fiber intake as part of preconception care should be considered.

Objectives: To evaluate the association between urinary 8-hydroxy-2'-deoxyguanosine (U8-OHdG) level-a marker of oxidative stress-and the incidence of preterm births (PTBs)., Design: Prospective cohort study., Setting: The Japan Environment and Children's Study (JECS)., Participants: Data from 92 715 women with singleton pregnancies at and after 22 weeks of gestation who were enrolled in the JECS, a nationwide birth cohort study, between 2011 and 2014 were analysed. U8-OHdG levels were assessed once in the second/third trimester using liquid chromatography-tandem mass spectrometry. Participants were categorised into the following three or five groups: low (<1.95 ng/mg urinary creatinine (Cre)), moderate (1.95-2.94 ng/mg Cre) and high (≥2.95 ng/mg Cre) U8-OHdG groups, or groups with <1.87, 1.87-2.20, 2.21-2.57, 2.58-3.11 and ≥3.12 ng/mg Cre. For stratification, participants with representative causes for artificial PTB were excluded., Primary and Secondary Outcome Measures: Adjusted OR (aOR) for PTB before 37 and 34 weeks of gestation were calculated using a multivariable logistic regression model while adjusting for confounding factors; the moderate or lowest U8-OHdG group was used as the reference, respectively., Results: The aORs for PTB before 37 weeks of gestation in the high U8-OHdG group were 1.13 (95% CI 1.05 to 1.22) and 1.13 (95% CI 1.04 to 1.23) after stratification. The aOR for PTB before 37 weeks in the fourth group was 0.90 (95% CI 0.81 to 0.99). After stratification, the aORs for PTB before 37 and 34 weeks in the fifth group were 1.15 (95% CI 1.03 to 1.29) and 1.46 (95% CI 1.08 to 1.97), respectively., Conclusions: High U8-OHdG levels were associated with increased PTB incidence, especially in participants without representative causes for artificial PTB. Our results can help identify the mechanisms leading to PTB, considering the variable aetiologies of this condition; further validation is needed to clarify clinical impacts., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

We evaluated the association between gestational age at threatened preterm birth (TPTB) diagnosis and preterm birth (PTB) incidence using a nationwide birth cohort. Data of 94,236 women with singleton deliveries from the Japan Environment and Children's Study (enrolled between 2011 and 2014) were analysed. Participants were divided based on parity and gestational age at TPTB diagnosis (22-24, 25-27, 28-30, 31-33, and 34-36 weeks). Multivariable logistic regression models were used to calculate the odds ratios (ORs) for PTB before 37 and 34 weeks in women from all groups, using participants without TPTB as the reference. The adjusted ORs for PTB before 37 weeks were the highest in the latest gestational age group in nulliparous and multiparous women without previous PTB, while those before 34 weeks were the highest in the earliest and latest gestational age group in multiparous women without previous PTB and in the earliest gestational age group in multiparous women with previous PTB. The association between gestational age at TPTB diagnosis and PTB incidence varies based on maternal parity and PTB before 37 or 34 weeks. Further studies with detailed clinical data and a unified TPTB diagnosis protocol are necessary to clarify this association., (© 2023. Springer Nature Limited.)

Objective: To evaluate the association between maternal asthma (MA) and obstetric complications, while considering subdivided total serum immunoglobulin E (IgE) levels., Methods: Data of the participants enrolled in the Japan Environment and Children's Study between 2011 and 2014 were analyzed. In total, 77,131 women with singleton live births at and after 22 weeks of gestation were included. MA was defined based on a self-administered questionnaire. Women with MA were stratified based on the quartile of total serum IgE levels during pregnancy as follows: low IgE levels (< 52.40 IU/mL), moderate IgE levels (52.40-331.00 IU/mL), and high IgE levels (> 331.00 IU/mL). The adjusted odds ratios (aORs) for preterm births (PTB), small for gestational age (SGA) infants, gestational diabetes mellitus, and hypertensive disorders of pregnancy (HDP) were calculated using multivariable logistic regression, while considering women without MA as reference and maternal socioeconomic factors as confounders., Results: The aORs for SGA infants and HDP in women with MA and high total serum IgE levels were 1.26 (95% confidence interval [CI], 1.05-1.50) and 1.33 (95% CI, 1.06-1.66), respectively. The aOR for SGA infants among women with MA and moderate total serum IgE levels was 0.85 (95% CI, 0.73-0.99). The aOR for PTB among women with MA and low total serum IgE levels was 1.26 (95% CI, 1.04-1.52)., Conclusions for Practice: MA with subdivided total serum IgE levels was associated with obstetric complications. Total serum IgE level may be a potential prognostic marker to predict obstetric complications in pregnancies with MA., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Although maternal triglyceride (TG) is important for fetal growth, there are few large cohort studies investigating the relationships between maternal TG during pregnancy and neonatal outcomes., Objectives: The objective of this study was to investigate the associations between maternal TG during the second and third trimesters and neonatal outcomes including preterm birth (PTB), low birth weight (LBW), small for gestational age (SGA) and large for gestational age (LGA)., Methods: This was a prospective birth cohort study using data of the Japan Environment and Children's Study included data of births from 2011-2014 in Japan including 79,519 pairs. Participants were divided into tertiles according to maternal TG in the second or third trimesters. Multiple logistic regression modeling was used to examine the risks of LBW, SGA, LGA and PTB in association with maternal TG levels in the second or third trimesters RESULTS: In the second trimester, compared with reference TG group (T2), women in higher TG group (T3) and lower TG group (T1) were also at increased risk of LGA (aOR 1.20, 95% CI 1.11-1.29) and SGA (aOR 1.25, 95% CI 1.10-1.41), respectively. In the third trimester, women in T3 and T1 were at increased risk of LGA (aOR 1.27, 95% CI 1.17-1.38) and SGA (aOR 1.17, 95% CI 1.02-1.34), respectively., Conclusion: In this study, higher maternal TG levels in the second or third trimesters were associated with risks of LGA, however, lower maternal TG levels in the second or third trimesters were conversely associated with risks of SGA., (Copyright © 2023. Published by Elsevier Inc.)

Background: Low birth weight (LBW), small for gestational age (SGA), and preterm birth (PTB) are important neonatal outcomes that may affect infant morbidity and mortality. The aim of this study is to investigate associations between maternal hemoglobin (Hb) concentrations and pregnancy outcomes of LBW, SGA, and PTB., Methods: This was a prospective birth cohort study using data of the Japan Environment and Children's Study. Participants were divided into five groups according to maternal Hb (g/dL) in the first and second trimesters: group 1, Hb < 9; group 2, 9 ≤ Hb < 11.0; group 3, 11.0 ≤ Hb < 13.0; group 4, 13.0 < Hb < 14.0; and group 5, 14.0 ≤ Hb. We examined the relationships between LBW, PTB, SGA, and maternal Hb in the first and second trimesters., Results: Excluding 29,673, a total of 74,392 newborns (first trimester: n  = 39,084, second trimester: n  = 35,308) were included. We obtained adjusted odds ratios (aORs) (95% confidence intervals (CIs)) using multivariate analysis; compared with group 3 in the first trimesters, women in group 1 were at increased risk of PTB (aOR, 3.20; 95% CI, 1.69-6.09), LBW (aOR, 2.21; 95% CI, 1.19-4.09). In the second trimester, multivariate analysis revealed that, compared with group 3 in the second trimester, women in group 1 were at increased risk of PTB (aOR, 2.30; 95% CI, 1.19-4.42) and women in group 5 were at increased risk of LBW (aOR, 1.87; 95% CI, 1.24-2.81) and PTB (aOR, 1.73; 95% CI, 1.06-2.83)., Conclusions: Elevated maternal Hb in the second trimester was associated with risks of PTB and LBW.

This study aimed to investigate the impact of Chlamydia trachomatis (CT) infection on pregnancy outcome in pregnant Japanese women. We utilized the data from a nationwide birth cohort study, the Japan Environment and Children's Study (JECS), for this study. We enrolled 26,385 individuals who could refer to data on pregnancy outcomes and confounding factors, with data on CT. Binominal logistic regression models were used to determine whether pregnant women with CT positivity were at more risk of experiencing adverse pregnancy outcomes, preterm birth (PTB), preterm prelabor rupture of membrane (pPROM), low birth weight (LBW) infants, small for gestational age (SGA) births, or hypertensive disorders of pregnancy (HDP). After adjusting for maternal age, parity, marital status, smoking status, and education status, there were no significantly increased risks of PTB, pPROM, LBW infants, SGA, and HDP in the odds ratios. No significant increase in the risk of adverse pregnancy outcomes was observed in any of the subgroup analyses, which were limited to the pregnancy women in Fukushima prefecture, where CT screening could be confirmed at 28-30 weeks of gestation. We believe that the results of this study will make a significant contribution to the future of medical care for pregnant women in Japan. Our findings are important for medical practitioners to contribute to the future medical treatment of Japanese pregnant women, and also to contribute to pre-conception care for Japanese society as a whole, including pregnant women., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2022 Yasuda et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: In reproductive medicine, vitamin D (VitD) is of particular interest because its deficiency has been linked to various infertility issues. Thus, preconception care, including appropriate VitD supplementation, is essential, especially in women using assisted reproductive technology (ART). Despite the therapeutic benefits of VitD, adverse events due to a high daily intake may influence obstetric outcomes. However, the effects of either low or high preconception VitD intake on obstetric outcomes, including the outcomes in women who used ART, remain unclear. Therefore, the aim of this study was to examine the association between pre-pregnancy daily VitD intake and obstetric outcomes in Japanese women, including those who conceived through ART., Methods: Data were obtained from the Japan Environment and Children's study database comprising 92,571 women recruited between January 2011 and March 2014 in Japan. Participants were categorized into five quintiles according to pre-pregnancy VitD intake (Q1 and Q5 had the lowest and highest VitD intake, respectively) and stratified according to the use of ART. Multiple logistic regression was performed to identify the effects of pre-pregnancy VitD intake on preterm birth (PTB), low-birth weight infant (LBW), and small for gestational age (SGA)., Results: Using Q3 (middle VitD intake) as a reference, our analysis revealed that Q5 (highest VitD intake) showed an increased risk of LBW < 1500 g (adjusted odds ratio [aOR]: 1.09, 95% confidence interval [CI]: 1.00-1.18) and SGA (aOR: 1.26, 95% CI: 1.14-1.39) among women who conceived without ART. Among women who conceived with ART, we found that Q5 (highest VitD intake) showed an increased risk of PTB at < 37 weeks (aOR: 2.05, 95% CI: 1.27-3.31)., Conclusion: The present study revealed that higher VitD intake before pregnancy may affect perinatal outcomes, particularly in women using ART. Our findings may facilitate personalized preconceptional counseling regarding VitD intake based on the method of conception, especially among women using ART., (© 2022. The Author(s).)

Purpose: To evaluate the association between disease activity, serological activity, and adverse pregnancy outcomes (APOs) in women with systemic lupus erythematosus (SLE) and determine the cut-off values of complements to predict APOs in live birth cases., Methods: This retrospective chart review included pregnant women with SLE who had singleton live births after 22 weeks between 2006 and 2020. First trimester maternal disease activity was assessed for SLE onset during pregnancy, antiphospholipid syndrome, SLE pregnancy disease activity index (SLEPDAI), disease flare-ups, lupus nephritis, pancytopenia, and daily prednisolone dosage. Serological activity was assessed for autoantibodies and complements. APOs included preterm birth (PTB), low birth weight infants, small-for-gestational age infants, preterm premature rupture of membranes, and preeclampsia (PE). Chi-square and Fisher's exact tests were used to compare categorical variables; a receiver-operating characteristic analysis was performed to calculate the cut-off values of complements to predict APOs., Results: Fifty-two participants met the inclusion criteria. The incidence of PTB and PE was associated with a high SLEPDAI (p < 0.001, p = 0.001), disease flare-ups (p = 0.007, p < 0.001), lupus nephritis (p = 0.020, p = 0.012), anti-dsDNA antibodies (p = 0.047, p = 0.016), anti-SSA antibodies (p = 0.003, p = 0.004), low CH 50 (p < 0.001, p < 0.001), low C3 (p < 0.001, p < 0.001), and low C4 (p < 0.001, p = 0.001), respectively. The cut-off values of C4 to predict PTB and PE were 13.0 mg/dL (higher than the normal lowest limit)., Conclusion: High maternal disease activity and high serological activity in the first trimester in women with SLE are significantly associated with APOs. Proper disease control and close management for hypocomplementemia are required for better perinatal outcomes., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Aim: Age at menarche is used as a risk indicator of gestational diabetes mellitus, preterm birth, and fetal growth. However, little is known regarding the age impact on obstetric outcomes among nulliparous women. This study investigated whether menarche age was correlated with obstetric outcomes among nulliparous women., Methods: We analyzed the data obtained for 37 645 singleton pregnancies between 2011 and 2014 in the Japan Environment and Children's Study. Age at menarche was categorized into the ≤9-, 10-, 11-, 12-, 13-, 14-, and ≥15-year-old groups (n = 363, 3155, 8390, 11 164, 6713, 5446, and 2414, respectively). We calculated the relative risk for cases of preterm birth <37 weeks, low birthweight <2500 g, small for gestational age, early and late-onset hypertension disorders of pregnancy, and early- and late-diagnosed (diagnosed < or ≧ 24 weeks) gestational diabetes mellitus using a reference of 12 years at menarche., Results: Women with an age at menarche ≤9 years showed an increased incidence of developing early-diagnosed gestational diabetes mellitus (relative risk: 2.42; 95% confidence interval: 1.05-5.60). A high body mass index before pregnancy increased the risk of developing gestational diabetes mellitus., Conclusions: Age at menarche helped in assessing the risk of early-diagnosed gestational diabetes mellitus among nulliparous women. Future studies are needed to clarify the underlying mechanisms. This study is the first to use data from the largest prospective birth cohort study of Japan and to investigate the relationship between menarche age and obstetric outcomes among nulliparous women., (© 2021 Japan Society of Obstetrics and Gynecology.)

There are limited studies on the long-term effects of natural/environmental disasters, especially nuclear disasters, on obstetric outcomes. This study aimed to review the results of perinatal outcomes immediately after the Great East Japan Earthquake (GEJE) and the Fukushima Daiichi Nuclear Power Plant accident, as well as their long-term trends over 8 years, in the Fukushima Health Management Survey. The annual population-based Pregnancy and Birth Survey is conducted as part of the Fukushima Health Management Survey. The Fukushima Prefecture government launched it to assess the health conditions of pregnant women and their neonates after the GEJE. The self-reported questionnaire was sent to 115,976 pregnant women by mail from January 2012, with 58,344 women responding to the questionnaire (50.3% response rate). Pregnancy complications, such as gestational hypertension, respiratory diseases, and mental disorders, increased in some women who were pregnant at the time of the earthquake and immediately after the earthquake. However, the direct effects on newborns, such as preterm birth, low birth weight, and congenital anomalies, were not immediately clear after the earthquake. Although there were significant differences in the occurrence of preterm birth and low birth weight among the districts, there was no change in the occurrences of preterm birth, low birth weight, or anomalies in newborns in Fukushima Prefecture from the fiscal year 2011 to the fiscal year 2018. Therefore, the long-term effects of the post-disaster radiation accident on perinatal outcomes are considered to be very small.

Background: This study aimed to investigate the effects of maternal exposure to external radiation on perinatal outcomes among women who experienced the Fukushima Daiichi Nuclear Disaster (FDND) using the Fukushima Health Management Survey (FHMS)., Methods: Data from the Pregnancy and Birth Survey and Basic Survey in the FHMS were combined to analyze external maternal radiation exposure following the FDND, and the relationship between radiation dose and perinatal outcomes was analyzed using binomial logistic regression analysis. Missing dose data were supplemented using multiple imputation., Results: A total of 6,875 individuals responded to the survey. Congenital anomalies occurred in 2.9% of patients, low birth weight (LBW) in 7.6%, small for gestation age (SGA; <10th percentile) in 8.9%, and preterm birth in 4.1%. The median maternal external radiation dose was 0.5 mSv (maximum, 5.2 mSv). Doses were classified as follows: <1 mSv (reference), 1 to <2 mSv, and ≥2 mSv. For congenital anomalies, the crude odds ratio for 1 to <2 mSv was 0.81 (95% confidence interval [CI], 0.56-1.17) (no participants with congenital anomaly were exposed to ≥2 mSv). At 1 to <2 mSv and ≥2 mSv, the respective adjusted odds ratios were 0.91 (95% CI, 0.71-1.18) and 1.21 (95% CI, 0.53-2.79) for LBW, 1.14 (95% CI, 0.92-1.42) and 0.84 (95% CI, 0.30-2.37) for SGA, and 0.91 (95% CI, 0.65-1.29) and 1.05 (95% CI, 0.22-4.87) for preterm birth., Conclusion: External radiation dose due to the FDND was not associated with congenital anomalies, LBW, SGA, or preterm birth.

Background: The effects of maternal ritodrine hydrochloride administration (MRA) during pregnancy on fetuses and offspring are not entirely clear. The present study aimed to evaluate the association between MRA and childhood wheezing using data from a nationwide Japanese birth cohort study., Methods: This study analyzed the data of the participants enrolled in the Japan Environment and Children's Study, a nationwide prospective birth cohort study, between 2011 and 2014. Data of women with singleton live births after 22 weeks of gestation were analyzed. The participants were divided according to MRA status. Considering childhood factors affecting the incidence of wheezing, including smoking environment and childhood viral infections, a logistic regression model was used to calculate odds ratios for "wheezing ever," diagnosis of asthma in the last 12 months, and "asthma ever" in women with MRA, with women who did not receive MRA as the reference. Additionally, participants were stratified by term births, and odds ratios for outcomes were calculated using a logistic regression model., Results: A total of 68,123 participants were analyzed. The adjusted odds ratio for wheezing was 1.17 (95% confidence interval, 1.12-1.22). The adjusted odds ratios for the other outcomes did not significantly increase after adjusting for childhood factors. The same tendency was confirmed after excluding women with preterm births., Conclusion: MRA was associated with a slightly increased incidence of childhood wheezing up to three years, irrespective of term or preterm birth status. It is important that perinatal physicians consider the potential effects of MRA on the offspring's childhood health., (© 2021 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.)

Aim: There is strong evidence that weekly intramuscular (IM) injections of 250 mg of 17-alpha-hydroxyprogesterone caproate (17-OHPC) reduce the risk of recurrent preterm birth (PTB); however, whether a lower dose of 17-OHPC could reduce the risk of recurrent PTB remains unclear. This study aimed to assess whether 125 mg of 17-OHPC reduces recurrent PTB among women with a prior singleton spontaneous PTB and cervical length >25 mm., Methods: This retrospective cohort study at a tertiary-care medical center in Japan included women with a prior singleton spontaneous PTB between 20 and 36 weeks' gestation and cervical length >25 mm, between 2008 and 2018. Primary outcomes were PTB <37 and <34 weeks' gestation. We calculated the adjusted odds ratio (aOR) and 95% confidence interval (CI) using a multiple logistic regression model. Gestational age at delivery was compared using the Kaplan-Meier survival curve and log-rank test., Results: Overall, 173 women met the inclusion criteria. Eighty-four women received weekly injections of 125 mg of 17-OHPC, and 89 did not. Treatment with 125 mg of 17-OHPC significantly reduced the risk of recurrent spontaneous PTB <37 (aOR: 0.156 [95% CI: 0.049-0.497]) and <34 weeks' gestation (aOR: 0.156 [95% CI: 0.049-0.497]). The mean delivery gestational age was also significantly longer in the 17-OHPC group (log-rank p = 0.005)., Conclusions: In this study population, weekly IM injections of 125 mg of 17-OHPC reduced the risk of recurrent PTB <37 and <34 weeks' gestation., (© 2021 Japan Society of Obstetrics and Gynecology.)

Objectives: Increased risk of preterm birth (PTB) in women with endometriosis is considered to be associated with chronic inflammatory conditions. Accordingly, we hypothesized that a prepregnancy antiinflammatory diet is a potential form of preconception care for preventing PTB in women with endometriosis and conducted this study to investigate the correlation of a prepregnancy antiinflammatory diet with obstetric outcomes in this patient population., Methods: We used singleton pregnancy data from the Japan Environment and Children's Study involving live births from 2011 to 2014. Individual meal patterns before pregnancy, derived through food frequency questionnaires, were used to calculate the Dietary Inflammatory Index. Participants were categorized according to Dietary Inflammatory Index quintiles (Q1 and Q5 were the most proinflammatory and antiinflammatory groups, respectively), and a multiple logistic regression model was used to estimate the effect of the antiinflammatory diet on PTB before 37 or 34 wk and on low birth weight (LBW) <2500 or 1500 g., Results: In women who did not undergo assisted reproduction, significantly reduced risk was found in the Q5 group for both PTB at <34 wk significantly decreased (adjusted odds ratio, 0.25; 95% confidence interval, 0.07-0.83) and low birth weight <1500 g (adjusted odds ratio, 0.07; 95% confidence interval, 0.01-0.60)., Conclusions: This study suggests a distinct effect of an antiinflammatory diet on more severe obstetric outcomes, specifically PTB before 34 wk and low birth weight <1500 g, for women with endometriosis. Preconception lifestyle can improve perinatal mortality and morbidity among these women., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Intrauterine inflammation affects short- and long-term neonatal outcomes. Histological chorioamnionitis and funisitis are acute inflammatory responses in the fetal membranes and umbilical cord, respectively. Although labor dystocia includes a potential risk of intrauterine inflammation, the risk of histological chorioamnionitis and funisitis of labor dystocia has not been evaluated yet. This study aimed to examine the association between labor dystocia and risk of histological chorioamnionitis and funisitis., Methods: In this retrospective cohort study, the cases who underwent histopathological examinations of the placenta and umbilical cord at Fukushima Medical University Hospital, Japan, between 2015 and 2020, were included. From the dataset, the pathological findings of the patients with labor dystocia and spontaneous preterm birth were reviewed. Based on the location of leukocytes, the inflammation in the placenta (histological chorioamnionitis) and umbilical cord (funisitis) was staged as 0-3. Multiple logistic regression analysis was performed to evaluate the risk of histological chorioamnionitis, histological chorioamnionitis stage ≥2, funisitis, and funisitis stage ≥2., Result: Of 317 women who met the study criteria, 83 and 144 women had labor dystocia and spontaneous preterm birth, respectively, and 90 women were included as controls. Labor dystocia was a risk factor for histological chorioamnionitis (adjusted odds ratio, 6.3; 95% confidential interval, 1.9-20.5), histological chorioamnionitis stage ≥2 (adjusted odds ratio, 6.0; 95% confidence interval, 1.7-21.8), funisitis (adjusted odds ratio, 15.4; 95% confidence interval, 2.3-101.3), and funisitis stage ≥2 (adjusted odds ratio, 18.5; 95% confidence interval, 2.5-134.0). Spontaneous preterm birth was also a risk factor for histological chorioamnionitis (adjusted odds ratio, 3.7; 95% confidence interval, 1.7-7.8), histological chorioamnionitis stage ≥2 (adjusted odds ratio, 3.0; 95% confidence interval, 1.2-7.9), and funisitis (adjusted odds ratio, 6.6; 95% confidence interval, 1.4-30.6). However, the adjusted odds ratio was smaller in spontaneous preterm births than in labor dystocia., Conclusion: Labor dystocia is a risk factor for severe histological chorioamnionitis and funisitis. Further studies are required to evaluate the effects of histological chorioamnionitis and funisitis on long-term neonatal outcomes.

This study aimed to clarify the association between uterine myomas and preterm birth (PTB), preterm premature rupture of membranes (pPROM), and intrauterine infection (II). The study was based on data from the Japan Environment and Children's Study, a nationwide birth-cohort study. Data of 86,370 women with singleton births after 22 weeks of gestation (with uterine myomas, n = 5354) were retrospectively analyzed. Using logistic regression, adjusted odds ratios (aORs) for PTB, pPROM, and II were calculated considering women without uterine myomas as the reference. Additionally, the effects of II on the incidence of PTB and pPROM were evaluated. In women with uterine myomas, the aORs for PTB before 37 and 34 weeks, pPROM, and II were 1.37 (95% confidence interval, 1.22-1.54), 1.61 (1.27-2.05), 1.65 (1.33-2.04), and 1.05 (0.75-1.46), respectively. The aORs for PTB and pPROM in women with II and uterine myomas were not significantly increased. Uterine myomas during pregnancy were associated with an increased incidence of PTB and pPROM. However, II in women with uterine myomas was not associated with an increased incidence of PTB or pPROM. These findings suggest a potential risk of occult PTB in pregnant women with uterine myomas., Competing Interests: The authors declare no conflicts of interest.

Objective: To validate the utility of fetal fibronectin (fFN) and cervical length (CL) in predicting preterm delivery among symptomatic nulliparous women., Methods: A retrospective cohort study of nulliparous women who presented with uterine contractions, abdominal pain, or cervical change at 21-34 gestational weeks at Fukushima Medical University Hospital, Japan, between 2008 and 2017. fFN (categorized as <50 ng/dL, 50-199 ng/dL, >200 ng/dL) and CL (≥15 mm or <15 mm) were evaluated simultaneously. Adjusted odds ratios (aORs) and confidence intervals (CIs) for preterm delivery before 37 or 34 weeks, and delivery within 28 or 14 days were calculated (references: fFN, <50 ng/dL; CL, ≥15 mm)., Result: Among 285 women who met the study criteria, CL less than 15 mm was a risk factor for preterm delivery before 37 (aOR, 4.1; 95% CI, 1.1-6.7) and 34 (aOR, 6.8; 95% CI, 2.3-20.2) weeks. fFN of 200 ng/dL or higher was a risk factor for delivery within 28 (aOR, 19.8; 95% CI, 4.3-90.2) and 14 (aOR, 10.8; 95% CI, 1.7-67.6) days., Conclusion: Among symptomatic nulliparous women, short CL was found to be a risk factor for preterm delivery and higher fFN levels were related to short gestational latency., (© 2019 International Federation of Gynecology and Obstetrics.)

Background: In Japan, mean maternal age at first childbirth is increasing. The aim of this study was to investigate whether maternal age at the first childbirth is a risk factor for preterm birth (PTB), low birth weight (LBW), and small for gestational age (SGA)., Methods: We used the results of Japan Environment and Children's Study (JECS) who gave birth in 2011-2014. Cases of primiparous singleton pregnancies where the subject was ≥20 years and delivered after 22 weeks were included. All subjects were categorized into five groups according to maternal age: 20-24, 25-29, 30-34, 35-39, and ≥40 years. Adjusted odds ratios (aORs) for PTB (before 37 and 34 weeks), LBW (<2,500 g and <1,500 g), and SGA were calculated using a logistic regression model, with the 20-24-year age group as reference., Results: We analyzed 38,412 singleton primiparous pregnancies. The aORs of all outcomes increased in parallel with each maternal age group >30 years. The aORs of PTB before 37 and 34 weeks, LBW <2,500 g, LBW <1,500 g, and SGA in the 30-34-year age group were 1.39 (95% confidence interval [CI], 1.16-1.67), 2.23 (95% CI, 1.45-3.41), 1.34 (95% CI, 1.18-1.53), 2.30 (95% CI, 1.35-3.94), and 1.24 (95% CI, 1.05-1.46), respectively., Conclusion: The present study showed that higher maternal age (>30 years) at the first childbirth was an independent risk factor for PTB, LBW, and SGA.

Introduction: This study evaluated the risk of preterm birth, low birthweight and small-for-gestational-age neonates born to mothers with adenomyosis during pregnancy., Material and Methods: We used the results of a Japanese nationwide prospective birth cohort study, identifying 93 668 singleton deliveries from 2011 to 2014. We identified 314 pregnancies with adenomyosis using self-reported questionnaires. Multiple logistic regression analyses were conducted to examine whether adenomyosis was associated with adverse pregnancy outcome. Maternal age, smoking status, method of conception, history of parity, fibroids, endometriosis and body mass index before pregnancy were analyzed as confounding factors., Results: Multiple logistic regression analysis showed that pregnancy with adenomyosis was a risk factor for preterm birth at less than 37 weeks (adjusted odds ratio [aOR: 2.49, 95% confidence interval [CI] 1.89-3.41), preterm birth at less than 34 weeks (aOR 1.91, 95% CI 1.02-3.55), low birthweight <2500 g (aOR 1.83, 95% CI 1.36-2.45), low birthweight <1500 g (aOR 2.39, 95% CI 1.20-4.77) and small-for-gestational-age neonates (aOR 1.68, 95% CI 1.13-2.51)., Conclusions: This study found that pregnancy with adenomyosis was associated with preterm birth, low birthweight and small-for-gestational-age neonates., (© 2018 Nordic Federation of Societies of Obstetrics and Gynecology.)

Histological chorioamnionitis (CAM) is one form of intrauterine inflammation that is often seen in cases of preterm birth and are usually confirmed based on pathological examination after delivery. Histological CAM is related to significant neonatal morbidity and mortality; however, its etiology is unknown. The objective of this study was to determine the risk factors for histological CAM, using medical background, including fetal heart rate (FHR) patterns in preterm birth cases. The preterm birth cases delivered between 28 and 36 weeks were categorized into two groups according to the presence of histological CAM. Ninety-five preterm infants were included: 48 infants without histological CAM and 47 cases with histological CAM. The odds ratio for histological CAM was adjusted for FHR patterns, gestational age, and delivery mode (vaginal delivery or Caesarean section). Logistic regression analysis showed that vaginal delivery and gestational age were associated with histological CAM (odds Ratio [OR]: 3.1, 95% confidence interval [CI]: 1.0-9.4, p < 0.05, and OR: 0.8, 95% CI: 0.6-0.9, p < 0.05, respectively). However, there were no specific FHR patterns associated with histological CAM. Our study indicates that in preterm birth cases, histological CAM is not related to any specific FHR pattern. However, labor uterine contraction and immature gestational age at the delivery are related to histological CAM. These results may provide better delivery management methods for preterm birth cases.

Aim: The aim of this study was to examine the association between medical institution change for perinatal care and gestational duration after the Great East Japan Earthquake using data from the Fukushima Health Management Survey., Methods: The data of pregnant women who experienced the earthquake in Fukushima prefecture and participated in the Pregnancy and Birth Survey as part of the Fukushima Health Management Survey were analyzed. The primary and secondary outcomes of this study were gestational duration and preterm birth, respectively. The main study factor was prenatal checkup institution (only one institution, changed institution due to self-referral, changed institution due to medical indication, and went to parents' home for childbirth). Self-referral was considered as indicative of relocation after the disaster. Multiple linear and logistic regression analyses were conducted to examine the effect of earthquake on each outcome., Results: A total of 5593 (60.2%) participants experienced the earthquake between the 4th and 37th weeks of their gestational period. After controlling for variables, pregnant women who changed their perinatal checkup institution due to medical indication were significantly associated with shorter gestational duration (β = -10.6, P < 0.001) and preterm birth (adjusted odds ratio, 8.5; 95% confidence interval, 5.8-12.5) compared with women who visited only one institution. Self-referral, however, was not significantly associated with the outcomes., Conclusion: According to prenatal checkup status, our results suggest that the effect on gestational duration of the Great East Japan Earthquake and the subsequent Fukushima Daiichi nuclear disaster was not significant., (© 2016 Japan Society of Obstetrics and Gynecology.)