Aims: This study investigated the association between maternal age and early and late gestational diabetes mellitus (GDM).Methods: In total, 72,270 pregnant women were included in this prospective birth cohort study. Associations between maternal age and early GDM (diagnosed at <24 gestational weeks) and late GDM (diagnosed at ≥24 gestational weeks) were evaluated using a multinomial logistic regression model with possible confounding factors. The reference category was maternal age of 30–34.9 years.Results: Higher maternal age was associated with higher odds of early and late GDM (P‐value for trend <0.0001 and <0.0001, respectively). The adjusted odds ratios (aORs) for early GDM with maternal age of 35–39.9 years and ≥40 were 1.399 (95% confidence interval [CI]: 1.134–1.725) and 2.494 (95% CI: 1.828–3.402), respectively. The aORs for late GDM with maternal age of 35–39 years and ≥40 were 1.603 (95% CI: 1.384–1.857) and 2.276 (95% CI: 1.798–2.881), respectively.Conclusions: Higher maternal age was associated with an increased risk of GDM regardless of when GDM was diagnosed. The association between maternal age and early GDM was similar to that between maternal age and late GDM.

Introduction. This is the first case report of septic abortion due to β-lactamase-negative ampicillin-resistant (BLNAR) non-typeable Haemophilus influenzae infection. In Japan, BLNAR H. influenzae is widespread and has become a clinical concern, especially in paediatrics and otolaryngology, but H. influenzae has not been previously recognized as a causative agent of obstetric or gynaecological infection. Case presentation. A 31-year-old pregnant woman presented at 17 weeks and 6 days of gestation with a high fever; she was admitted with a diagnosis of threatened premature delivery. Despite tocolytic treatment, she aborted spontaneously 2 h after admission and then entered septic shock. BLNAR H. influenzae was detected in both blood and vaginal cultures. Her condition gradually improved after several days of treatment with cefotaxime, and she was ultimately discharged without sequelae or complaints. Conclusion. Although penicillin with a β-lactamase inhibitor is currently recommended for the treatment of septic abortion, this combination will probably lead to treatment failure in the case of BLNAR H. influenzae infection. As this study reveals, H. influenzae can cause septic abortion; hence, future efforts should be undertaken to detect and therapeutically target this pathogen during pregnancy.

Aims: This study aimed to investigate the association of maternal birth weight (MBW) with early and late gestational diabetes mellitus (GDM).Methods: A total of 69318 pregnant Japanese women were included in this birth cohort study. The associations between maternal birth weight and early gestational diabetes mellitus (diagnosed at <24 gestational weeks) and late GDM (diagnosed at ≥24 gestational weeks) were investigated using a multinomial logistic regression model, with an maternal birth weight of 3000–3499 g as the reference category.Results: Lower maternal birth weight was associated with higher odds of developing early and late gestational diabetes mellitus (P < 0.0001 and P < 0.0001, respectively). The adjusted odds ratios (aORs) for early gestational diabetes mellitus in participants with a MBW of <2500 g and 2500–2999 g were 1.345 (95% confidence interval [CI]: 0.912–1.984) and 1.338 (95% CI: 1.098–1.629), respectively. The aORs for late gestational diabetes mellitus in participants with a MBW of <2500 g and 2500–2999 g were, 1.657 (95% CI: 1.298–2.115) and 1.218 (95% CI: 1.058–1.402), respectively.Conclusions: Regardless of the gestational age when gestational diabetes mellitus was diagnosed, a lower maternal birth weight was associated with an increased risk of gestational diabetes mellitus. Furthermore, the association of a MBW <2500 g with late gestational diabetes mellitus tended to be stronger than that with early gestational diabetes mellitus.

This study aimed to evaluate the association between parental and infant birth weights in Japan. In total, 37,504 pregnant Japanese women and their partners were included in this birth cohort study. A multinomial logistic regression model was used to evaluate the associations of parental birth weights with small-for-gestational-age (SGA) or large-for-gestational-age (LGA) infants. Associations between parental birth weight and low birth weight (LBW) infants or macrosomia were also examined, and linear associations between parental birth weight and SGA or LGA were found. The adjusted odds ratios (aORs) for SGA infants per 500 g decrease in maternal and paternal birth weights were 1.50 (95% confidence interval [CI],1.43–1.58) and 1.31 (95% CI, 1.25–1.38), respectively. The aORs for LGA infants per 500 g increase in maternal and paternal birth weights were 1.53 (95% CI, 1.47–1.60) and 1.41 (95% CI, 1.35–1.47), respectively. The association between parental birth weight and LBW infants or macrosomia was also linear. The aORs for LBW infants per 500 g decrease in maternal and paternal birth weights were 1.47 (95% CI, 1.40–1.55) and 1.25 (95% CI, 1.19–1.31), respectively. The aORs for macrosomia per 500 g increase in maternal and paternal birth weights were 1.59 (95% CI, 1.41–1.79) and 1.40 (95% CI, 1.23–1.60), respectively. Parental birth weight was found to be associated with infant birth weight even after adjusting for various parental factors. Furthermore, maternal birth weight was more strongly associated with infant birth weight than with paternal birth weight.

In this study, we aimed to reveal the trends of self‐measured blood pressure (SMBP) and SMBP‐derived indices during pregnancy and the postpartum period. The Babies and Their Parents Longitudinal Observation in Suzuki Memorial Hospital in the Intrauterine Period (BOSHI) Study is a prospective cohort study in Japan. Participants were instructed to measure SMBP daily during pregnancy and for 1 month after delivery. Among 237 participants with normotensive blood pressure (BP) during pregnancy and the postpartum period who were analyzed using mixed‐effects models for repeated measures, the SMBP was measured, on average, 14.3 times from the day before delivery to 28 days postpartum. The systolic blood pressure (SBP) and diastolic blood pressure (DBP) on the day before delivery were 110.6 ± 1.0 and 68.1 ± 0.8 mmHg (estimate ± standard error). Postpartum BP increased from postpartum Days 3–8 in SBP and from Days 3–22 in DBP, compared to that on the day before delivery. The SBP and DBP were 4.9 and 4.7 mmHg higher on postpartum Days 8 and 7 than the day before pregnancy, respectively. During pregnancy, the pulse rate (PR) showed an inverted U‐shaped trend and then sharply increased rapidly until the first postpartum day after delivery. The Shock Index showed a similar trend to that of the PR, decreased from labor until postpartum Day 8, and plateaued thereafter. The double product peaked during labor, remained higher than the prelabor levels for approximately 10 days, and then decreased in the postpartum period.

This study aimed to investigate the association between maternal birth weight (MBW) with preterm delivery (PTD) in the Japanese population. To this end, a total of 78,972 Japanese pregnant women were included in a prospective birth cohort study. Multiple logistic regression and multinominal logistic regression models were applied to investigate the associations of MBW with PTD (delivery from 22 to < 37 weeks of gestation), early PTD (delivery from 22 to < 34 weeks), and late PTD (delivery from 34 to < 37 weeks). The results showed that MBW was inversely associated with PTD, early PTD, and late PTD (p-for-trend < 0.0001, 0.0014, and < 0.0001, respectively). The adjusted odds ratios per each 500 g of MBW decrease were 1.167 (95% confidence interval [CI]: 1.118–1.218) for PTD, 1.174 (95% CI: 1.070–1.287) for early PTD and 1.151 (95% CI: 1.098–1.206) for late PTD. The effect size of the association of MBW with early PTD was similar to that with late PTD. This study demonstrated for the first time an association of a low MBW with PTD, early PTD, and late PTD in a Japanese nationwide cohort.