An adverse in utero experience negatively impacts perinatal growth in livestock. Maternal heat stress (HS) during gestation reduces placental growth and function. This progressive placental insufficiency ultimately leads to fetal growth restriction (FGR). Studies in chronically catheterized fetal sheep have shown that FGR fetuses exhibit hypoxemia, hypoglycemia, and lower anabolic hormone concentrations. Under hypoxic stress and nutrient deficiency, fetuses prioritize basal metabolic requirements over tissue accretion to support survival. Skeletal muscle is particularly vulnerable to HS-induced placental insufficiency due to its high energy demands and large contribution to total body mass. In FGR fetuses, skeletal muscle growth is reduced, evidenced by smaller myofiber size and mass, reduced satellite cell proliferation, and slower rate of protein synthesis. Disruptions in skeletal muscle growth are associated with mitochondrial dysfunction, including reduced pyruvate flux into the mitochondrial matrix and lower complex I activity in the mitochondrial electron transport chain. This review summarizes current research on the mechanisms by which HS-induced placental insufficiency affects skeletal muscle growth in the fetus, with an emphasis on myogenesis, hypertrophy, protein synthesis, and energy metabolism. The evidence presented is primarily drawn from experiments using chronically catheterized fetal sheep exposed to maternal HS during mid-gestation. Additionally, we explore emerging nutritional strategies aimed at enhancing skeletal muscle growth in animals with FGR. These strategies hold promise not only for improving reproductive efficiency in livestock affected by prenatal stress but also for their translational relevance to human pregnancies complicated by placental insufficiency.

Using a behavioural intervention to target nutrition during pregnancy may be key in meeting recommendations for healthy eating. The aim was to assess the use of a short-term dietary intake measurement tool (3-day food intake record) to infer long-term habitual dietary intake during pregnancy (using a short-form food frequency questionnaire). A convenience sample (n=90) between 12- and 18-weeks’ gestation were recruited from a larger randomised controlled trial for cross-sectional analysis. Participants completed a 44-item food frequency questionnaire and 3-day food intake record. Using the participant food intake record, the investigator blindly completed a second frequency questionnaire. The frequency questionnaires were scored using Dietary Quality Scores (DQS) and compared. Aggregate data were evaluated using a Wilcoxon signed rank test, and individual-level data were evaluated using a Bland-Altman plot. No significant difference was observed in the scores (Z=-1.88, p=0.06), with small effect size (r=0.19). The Bland-Altman plot showed that comparing the DQS derived from the two different dietary assessments underestimated scores by a mean difference of 0.4 points (95% limits of agreement: -3.50 to 4.26). The data points were evenly spread suggesting no systematic variation for over- or underestimation of scores. Minimal difference was observed between the functionality of the two assessment instruments. However, the food intake record can be completed by pregnant individuals to estimate short-term nutrient intake, and then scored by the investigator to estimate long-term dietary quality. Combining these two instruments may best capture the most accurate representation of dietary habits over time.

Acute infection with Toxoplasma gondii in pregnant people can lead to vertical transmission to the foetus and congenital toxoplasmosis. As part of risk assessment, the epidemiology of toxoplasmosis among pregnant people must be quantitatively elucidated. Herein, we investigated the risk of primary T. gondii infection during pregnancy in Japan, estimating the incidence of T. gondii infection among pregnant people as well as that of congenital toxoplasmosis. We used a compartment model that captured the infection dynamics in pregnant people, analysing prescription data for spiramycin in Japan, together with local serological testing results and the screening rate of primary T. gondii infection during pregnancy. The nationwide risk of T. gondii infection pregnant people in Japan was estimated to be 0.016% per month. Among prefectures investigated, the risk estimate was highest in Tokyo with 0.030% per month. Nationally, the number of T. gondii infections among pregnant people in the years 2019, 2020, and 2021 was estimated to be 1507, 1440, and 1388 infections, respectively. The nationwide number of cases of congenital toxoplasmosis in each year was estimated at 613, 588, and 567 cases, respectively. Our study indicated that T. gondii infection continues to place a substantial burden on public health in Japan.

Lamotrigine is beneficial in bipolar disorder and is often prescribed to patients during their period of reproductive potential. We summarise aspects of the pharmacology of lamotrigine, highlight its uses in psychiatric practice, drawing attention to recent findings relating to potential hazards arising from lamotrigine exposure in utero, and make some suggestions for clinical management.

During pregnancy, colonization by genital mycoplasmas may be associated with adverse outcomes. This study was conducted to investigate the prevalence of four species of Mollicutes (Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma parvum, and Ureaplasma urealyticum) in pregnant women receiving high-risk prenatal care and to evaluate possible associated factors. Data collection included the application of a questionnaire and the collection of cervical swabs from pregnant women. Species identification was performed by real-time PCR. The overall prevalence of Mollicutes was 60.97%. 55.9% of pregnant women were colonized by Ureaplasma spp., and 19.51% by Mycoplasma spp. The prevalence rates by species were 48.78% for U. parvum, 11.59% for U. urealyticum, 18.9% for M. hominis, and 1.22% for M. genitalium. Age, 12 years of schooling or more, age at first sexual intercourse up to 14 years, third trimester of pregnancy, having undergone infertility treatment, presence of STI, and groin lymph nodes were associated with a higher prevalence of microorganisms. The results presented are of utmost importance for understanding the prevalence of these microorganisms, the characteristics of colonized pregnant women, and planning screening strategies and interventions that minimize the negative impacts of these infections.

Several dietary strategies are designed to achieve optimal glycaemic control in managing gestational diabetes mellitus (GDM), considering factors such as energy needs, the glycaemic index, high fibre content and the reduction or exclusion of sugary foods and drinks. However, in achieving therapeutic goals, there is a lack of consensus in the formulation of uniform recommendations. This article reviews the literature to assess the impact of dietary interventions on GDM risk – measured by the percentage of at-risk women who develop GDM – and on the progression of GDM pregnancies, including weight gain, hyperglycaemia severity, insulin requirements and perinatal outcomes such as macrosomia, hypertensive disorders, caesarean delivery and neonatal size. We conducted a thorough search of PubMed and the Cochrane Library, focusing on randomised controlled trials, cohort studies, systematic reviews and meta-analyses involving women either at risk of or diagnosed with GDM. These search criteria yielded 2800 articles, whose titles and abstracts were reviewed to determine their relevance to the research objective. In the initial search, 192 relevant articles met the inclusion criteria. The comprehensive analysis of these studies highlights the current uncertainty regarding the long-term consequences of recommended diets during pregnancy, especially among women with GDM. While the available literature is substantial, conclusions drawn from various methodologies and study populations have not yielded a consensus on the most effective diet for reducing perinatal complications. Nonetheless, it is reasonable to advocate for the early initiation of dietary interventions, particularly during pregnancy planning, especially among women exhibiting risk factors for GDM.