BackgroundThe Institute of Medicine (IOM) guidelines are the most widely used guidelines on gestational weight gain; however, accumulation of evidence that body composition in Asians differs from other races has brought concern regarding whether their direct application is appropriate. We aimed to study to what extent optimal gestational weight gain among women in Japan differs by pre-pregnancy body mass index (BMI) and to compare estimated optimal gestational weight gain to current Japanese and Institute of Medicine (IOM) recommendations.MethodsWe retrospectively studied 104,070 singleton pregnancies among nulliparous women in 2005–2011 using the Japanese national perinatal network database. In five pre-pregnancy BMI sub-groups (17.0–18.4, 18.5–19.9, 20–22.9, 23–24.9, and 25–27.4 kg/m2), we estimated the association of the rate of gestational weight gain with pregnancy outcomes (fetal growth, preterm delivery, and delivery complications) using multivariate regression.ResultsWeight gain rate associated with the lowest risk of adverse outcomes decreased with increasing BMI (12.2 kg, 10.9 kg, 9.9 kg, 7.7 kg, and 4.3 kg/40 weeks) for the five BMI categories as described above, respectively. Current Japanese guidelines were lower than optimal gains, with the lowest risk of adverse outcomes for women with BMI below 18.5 kg/m2, and current IOM recommendations were higher than optimal gains for women with BMI over 23 kg/m2.ConclusionOptimal weight gain during pregnancy varies largely by pre-pregnancy BMI, and defining those with BMI over 23 kg/m2 as overweight, as proposed by the World Health Organization, may be useful when applying current IOM recommendations to Japanese guidelines.

Caesarean section (CS) is increasing globally, and women with prior CS are at higher risk of uterine rupture in subsequent pregnancies. However, little is known about the incidence, risk factors, and outcomes of uterine rupture in women with prior CS, especially in developing countries. To investigate this, we conducted a secondary analysis of the World Health Organization Multicountry Survey on Maternal and Newborn Health, which included data on delivery from 359 facilities in 29 countries. The incidence of uterine rupture among women with at least one prior CS was 0.5% (170/37,366), ranging from 0.2% in high-Human Development Index (HDI) countries to 1.0% in low-HDI countries. Factors significantly associated with uterine rupture included giving birth in medium- or low-HDI countries (adjusted odds ratio [AOR] 2.0 and 3.88, respectively), lower maternal educational level (≤6 years) (AOR 1.71), spontaneous onset of labour (AOR 1.62), and gestational age at birth <37 weeks (AOR 3.52). Women with uterine rupture had significantly higher risk of maternal death (AOR 4.45) and perinatal death (AOR 33.34). Women with prior CS, especially in resource-limited settings, are facing higher risk of uterine rupture and subsequent adverse outcomes. Further studies are needed for prevention/management strategies in these settings.

BackgroundThe relationship between maternal hemoglobin (Hb) levels during pregnancy and birth outcomes has been controversial. Changes in Hb level during pregnancy may have an impact on birth outcomes. This study aimed to investigate whether changes in Hb levels from early to mid- or late pregnancy is associated with birth outcomes.MethodsParticipants were singleton mothers who delivered at the National Center for Child Health and Development between 34 and 41 weeks of gestation in 2010 and 2011 (n = 1,986). Hb levels were measured at three time points: early (<16 weeks), mid- (16–27 weeks), and late (28–36 weeks) pregnancy. Associations between changes in Hb levels from early to mid- or late pregnancy and birth outcomes (birth weight, Z-score of birth weight, placental weight, and placental ratio) were assessed by multiple regression, adjusting for maternal and fetal covariates.ResultsA smaller reduction in Hb levels from early to mid- or late pregnancy was significantly associated with lower birth weight, Z-score of birth weight, placental weight, and placental ratio. Compared to women with an intermediate reduction from early to late pregnancy, women with the least reduction had a significantly increased risk of delivering low birth weight (LBW) (adjusted odds ratio [aOR], 2.0; 95% confidence interval [CI], 1.3-3.1) and small-for-gestational-age (SGA) (aOR, 1.6; 95% CI, 1.04-2.3) infants, while women with the greatest reduction had a significantly decreased risk of delivering SGA (aOR, 0.38; 95% CI, 0.23-0.65) infants, but an increased risk of high placental ratio (aOR, 1.7; 95% CI, 1.2-2.5).ConclusionsHb changes from early to mid- or late pregnancy were inversely associated with birth weight, placental weight, and placental ratio.

Not applicable.

Since the first baby in Japan conceived as a result of in vitro fertilization (IVF) was born in 1983, the number of assisted reproductive technology (ART) cycles has increased dramatically each year. According to the latest preliminary report from the International Committee Monitoring Assisted Reproductive Technologies for ART worldwide in 2016, Japan was the second largest user of ART worldwide in terms of the annual total number of treatment cycles performed. 1

http://hyper.ahajournals.org/ Downloaded from Watanabe et al S(P)RR During Pregnancy 1251invasion and migration. 16,17 Clinically during pregnancy, it is well-known that even women with no complication exhibit BP changes with gestational age; the BP is typically at its lowest between 24 and 26 gestational weeks, increasing thereafter until the end of the pregnancy. 18 In addition, the circulating RAS is involved in the development of hypertensive disorders, including preeclampsia, during pregnancy. 1,16,19 However, no evidence suggests that the tissue RAS contributes to BP changes during pregnancy.On the basis of these background findings, the present study was conducted to examine whether the tissue RAS contributed to BP changes during pregnancy and the incidence of preeclampsia. To this end, we assessed the relationship between plasma s(P)RR concentrations and BP levels during pregnancy in a prospective cohort study. Methods Study ParticipantsIn this prospective cohort study, Japanese pregnant women whose first visit to the National Center for Child Health and Development hospital was at <16 weeks and 0 days of gestation were enrolled between January and December 2010. At recruitment, written informed consent was obtained from all participants. The study protocol was approved by the ethics committee of the National Center for Child Health and Development (Tokyo, Japan).The expected due date was confirmed by ultrasound in all participants. Inclusion criteria were systolic BP <140 mm Hg and diastolic BP <90 mm Hg at the time of enrollment (<16 weeks of gestation) and the absence of preexisting hypertensive disorders and renal disease. The study initially enrolled 477 pregnant women who met the criteria; however, 40 pregnant women were excluded because of early abortion (n=8) or the inability to follow-up because of relocation (n=32), resulting in a total of 437 study participants.Plasma samples were obtained at 3 prenatal visits throughout the pregnancy and at time of delivery. The first sample was obtained before 16 weeks 0 days gestation (early pregnancy), the second between 16 weeks 0 days and 27 weeks 6 days gestation (mid-pregnancy), and the third after 28 weeks 0 days gestation (late pregnancy) at routine blood testing during prenatal visits. The fourth blood sample was obtained at time of delivery. We determined s(P)RR concentrations for first, second, and third trimester using the blood samples obtained in early, middle, and late pregnancy, respectively. We then analyzed s(P) RR concentrations in early pregnancy in association with BP values measured at 16 to 20, 20 to 24, 24 to 28, 28 to 32, 32 to 36, and 36 to 40 weeks of gestation (6 periods). Similarly, s(P)RR concentrations in mid-pregnancy were analyzed in association with BP levels measured at 28 to 32, 32 to 36, and 36 to 40 weeks gestation (3 periods) and s(P)RR concentrations in late pregnancy with BP levels measured at 36 to 40 weeks gestation (1 period). Finally, s(P)RR at delivery was used for analysis of the association between s(P)RR conce...

Objective: To investigate the latent effect of breastfeeding on overweight and obesity in late childhood. Methods: Data on breastfeeding and child anthropometric measurements were collected annually from a nation-wide population-based prospective cohort study in Japan (21,425 boys and 20,147 girls). Breastfeeding status (exclusiveness and duration) was assessed when the child was 6 months old. Mixed effects models were used to evaluate trajectories of body mass index (BMI), together with overweight and obesity status, from 1.5 to 8 years of age. Results: Mixed-fed boys and exclusively breastfed boys showed lower BMI as the main effect, as well as a slower increase of inclination in BMI as interaction term between feeding type and age, than exclusively formula-fed boys. Breastfed boys had lower BMI at the ages of 7 and 8, in comparison with exclusively formula fed boys (P 5 0.002 and P < 0.001, respectively). A similar association was found for girls, although the main effect of feeding type was not statistically significant. The analysis of breastfeeding duration had similar results. Conclusions: Breastfeeding, even if partial or for short duration, has a latent protective effect against overweight and obesity in late childhood, especially for boys.

PurposeThe Japan Society of Obstetrics and Gynecology (JSOG) has collected cycle‐based assisted reproductive technology (ART) data in an online registry since 2007. Herein, we present the characteristics and treatment outcomes of ART cycles registered during 2017.MethodsWe collected cycle‐specific information for all ART cycles implemented at participating facilities and performed descriptive analysis.ResultsIn total, 448,210 treatment cycles and 56,617 neonates (1 in 16.7 neonates born in Japan) were reported in 2017, increased from 2016; the number of initiated fresh cycles decreased for the first time ever. The mean patient age was 38.0 years (standard deviation 4.6). A total 110,641 of 245,205 egg retrieval cycles (45.1%) were freeze‐all cycles; fresh embryo transfer (ET) was performed in 55,720 cycles. A total 194,415 frozen‐thawed ET cycles were reported, resulting in 66,881 pregnancies and 47,807 neonates born. Single ET (SET) was performed in 81.8% of fresh transfers and 83.4% of frozen cycles, with singleton pregnancy/live birth rates of 97.5%/97.3% and 96.7%/96.6%, respectively.ConclusionsTotal ART cycles and subsequent live births increased continuously in 2017, whereas the number of initiated fresh cycles decreased. SET was performed in over 80% of cases, and ET shifted from using fresh embryos to frozen ones.