Background: Vitamin D concentrations during pregnancy are measured to diagnose states of insufficiency or deficiency. The aim of this study is to apply accurate assays of vitamin D forms [single- hydroxylated [25(OH)D₂, 25(OH)D₃], double-hydroxylated [1α,25(OH)₂D₂, 1α,25(OH)₂D₃], epimers [3-epi-25(OH)D₂, 3-epi-25(OH)D₃] in mothers (serum) and neonates (umbilical cord) to i) explore maternal and neonatal vitamin D biodynamics and ii) to identify maternal predictors of neonatal vitamin D concentrations. Methods: All vitamin D forms were quantified in 60 mother- neonate paired samples by a novel liquid chromatography -mass spectrometry (LC-MS/MS) assay. Maternal characteristics [age, ultraviolet B exposure, dietary vitamin D intake, calcium, phosphorus and parathyroid hormone] were recorded. Hierarchical linear regression was used to predict neonatal 25(OH)D concentrations. Results: Mothers had similar concentrations of 25(OH)D₂ and 25(OH)D₃ forms compared to neonates (17.9 ± 13.2 vs. 15.9 ± 13.6 ng/mL, p = 0.289) with a ratio of 1:3. The epimer concentrations, which contribute approximately 25% to the total vitamin D levels, were similar in mothers and neonates (4.8 ± 7.8 vs. 4.5 ± 4.7 ng/mL, p = 0.556). No correlation was observed in mothers between the levels of the circulating form (25OHD₃) and its active form. Neonatal 25(OH)D₂ was best predicted by maternal characteristics, whereas 25(OH)D₃ was strongly associated to maternal vitamin D forms (R² = 0.253 vs. 0.076 and R² = 0.109 vs. 0.478, respectively). Maternal characteristics explained 12.2% of the neonatal 25(OH)D, maternal 25(OH)D concentrations explained 32.1%, while epimers contributed an additional 11.9%. Conclusions: By applying a novel highly specific vitamin D assay, the present study is the first to quantify 3-epi-25(OH)D concentrations in mother - newborn pairs. This accurate assay highlights a considerable proportion of vitamin D exists as epimers and a lack of correlation between the circulating and active forms. These results highlight the need for accurate measurements to appraise vitamin D status. Maternal characteristics and circulating forms of vitamin D, along with their epimers explain 56% of neonate vitamin D concentrations. The roles of active and epimer forms in the maternal - neonatal vitamin D relationship warrant further investigation.

Endocrine-disrupting chemicals (EDCs) are exogenous compounds that interfere with the endocrine system by mimicking or blocking the action of endogenous hormones such as estrogens, androgens, and thyroid hormones. This systematic review aims to evaluate the current epidemiological evidence linking EDC exposure with adverse reproductive outcomes in males and females of reproductive age. A total of 14 observational studies published between 2014 and 2024 were included following structured searches in PubMed, Scopus, and Google Scholar. The most commonly studied EDCs included bisphenol A (BPA), its analogs (such as bisphenol S, BPS), phthalates, parabens, per- and polyfluoroalkyl substances (PFAS), and persistent organic pollutants (POPs). The review found consistent associations between EDC exposure and multiple reproductive endpoints, such as impaired semen quality, decreased ovarian reserve, infertility, polycystic ovary syndrome (PCOS), altered hormone levels—specifically estradiol (E2), luteinizing hormone (LH), and follicle-stimulating hormone (FSH)—and adverse outcomes in assisted reproductive technologies (ART), including in vitro fertilization (IVF). Despite methodological heterogeneity, the findings support the biological plausibility of EDCs in disrupting reproductive function. The review highlights the urgent need for regulatory measures, increased public awareness, and longitudinal studies to assess the cumulative effects of chronic EDC exposure on human fertility.

Ceramides are a group of sphingolipids located in the external plasma membrane layer and act as messengers in cellular pathways such as inflammatory processes and apoptosis. Plasma ceramides are biomarkers of cardiovascular disease, type 2 diabetes mellitus, Alzheimer’s disease, various autoimmune conditions and cancer. During pregnancy, ceramides play an important role as stress mediators, especially during implantation, delivery and lactation. Based on the current literature, plasma ceramides could be potential biomarkers of obstetrical adverse outcomes, although their role in metabolic pathways under such conditions remains unclear. This review aims to present current studies that examine the role of ceramides during pregnancy and obstetrical adverse outcomes, such as pre-eclampsia, gestational diabetes mellitus and other complications.

Background: Maternal vitamin D status during pregnancy has been hypothesized to influence offspring neurodevelopment; however, the evidence remains inconsistent. Methods: We studied 66 mother–child pairs from the KLOTHO cohort with serum 25-hydroxyvitamin D [25(OH)D] measurements at delivery (maternal and umbilical cord). At 10 years of age, neurodevelopment was assessed using standardized questionnaires, generating composite z-scores for cognitive (cognitive, communication, motor) and psychosocial (social–sentimental, special interests) domains. Multivariable models were adjusted for sex, maternal body mass index and education, and neonatal birth weight and gestational age. Results: Maternal 25(OH)D deficiency (<50 nmol/L) was not associated with cognitive composite scores (p = 0.77). The psychosocial composite scores showed a non-significant negative trend (p = 0.29). Neonatal deficiency showed no consistent association with cognition (p = 0.99) or psychosocial outcomes (p = 0.30). Exploratory partial correlations suggested a positive association between maternal 25(OH)D and psychosocial development (r = 0.60, p = 0.038, n = 12). Seasonal variation in maternal vitamin D was observed (autumn: 56.0 ± 24.6 vs. winter: 32.0 ± 18.3 nmol/L; p < 0.0001), but did not translate into differences in 10-year outcomes. Conclusions: In this cohort of 66 pairs, perinatal vitamin D status was not a determinant of global cognition at 10 years of age. A potential link with psychosocial development requires replication in larger longitudinal studies. Due to the limited sample size, all findings should be interpreted as exploratory.