Pregnancy-related maternal physiological adaptations and fetal chemical exposure

Higher PFOS exposure associated with higher SHBG in third trimester. The Odense Child Cohort

BACKGROUND

Perfluoroalkyl substances (PFAS) are chemicals with endocrine disrupting properties. Experimental studies indicate that PFAS have estrogenic effects by inducing aromatase activity. Sex hormone-binding globulin (SHBG) is a marker of the balance between estrogen and testosterone, as estrogen stimulates and testosterone inhibits SHBG production.

OBJECTIVE

To investigate associations between maternal PFAS concentrations and levels of SHBG and testosterone in pregnancy.

METHODS

In Odense Child Cohort (OCC), concentrations of PFAS: perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) were measured in 1611 eligible women at median gestational week (GW) 12 (25th, 75th percentile: 10, 15). Among these, levels of sex hormone-binding globulin (SHBG), calculated free testosterone (Free-T), free androgen index (FAI), and total testosterone (TT) were assessed in 1048 at median GW 29 (25th, 75th percentile: 28, 30). Associations between PFAS concentrations and levels of SHBG and testosterone were estimated using multiple linear regression models. The effect of combined exposure to PFAS was also assessed via Quantile G-Computation.

RESULTS

A doubling in PFOS concentration was associated with an increment in SHBG concentration by 2.29% (95%CI: 0.04%, 4.59%) in adjusted analyses. PFOS exposure in the third tertile, as compared to the first tertile, significantly increased SHBG concentrations by 4.60% (95%CI: 0.82%, 8.53%). No significant association was demonstrated between PFAS and TT, however, a non-significant inverse association was found between PFAS and Free-T and FAI. Combined PFAS exposure was non-significantly associated with an increase in SHBG, and decrease in Free-T, FAI, and TT.

CONCLUSION

PFOS exposure was associated with an increase in the proportion of estrogen effects to androgen effects, assessed by higher SHBG concentrations, in pregnant women. Estrogenic effects during pregnancy may have implications on offspring neural, metabolic, and endocrine development, hence supporting the necessity of a follow-up of offspring.

Association between Phthalate exposure and Reproductive Health in Patients Undergoing Assisted Reproductive Treatment: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis synthesizes current literature examining the relationship between phthalate exposure and reproductive health in patients undergoing assisted reproductive treatment (ART). We conducted a comprehensive search across multiple databases, including PubMed, Web of Science, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (CBM), China Science and Technology Journal Database (VIP), and Wanfang databases. From 16 relevant publications identified, five studies were included in the systematic review and 11 in the meta-analysis. Our findings indicate that most of the 18 phthalate metabolites analyzed demonstrated negative associations with reproductive health outcomes in ART patients. High molecular weight phthalates, particularly mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), were most frequently linked to adverse outcomes, followed by metabolites such as mono-isobutyl phthalate (MiBP), mono-benzyl phthalate (MBzP). Both high and low molecular weight phthalates, including monoethyl phthalate (MEP) and MiBP, were correlated with negative reproductive outcomes. However, no significant associations were observed between mono-2-ethyl-5-hydroxyhexyl terephthalate (MEHHTP) or mono-3-hydroxybutyl phthalate (MHBP) and reproductive health parameters. Our analysis suggests that phthalate exposure may adversely affect fertility, hormone levels, and gamete quality, while also being associated with pregnancy complications and oxidative stress. These findings underscore the need for further large-scale studies to confirm these relationships and their clinical implications.

Endocrine-disrupting chemicals and female reproductive health: a growing concern

Female fertility and reproductive health depend on a series of developmental steps from embryogenesis through puberty, in addition to the proper functioning of the reproductive system in adulthood. Two important steps are the establishment of the ovarian reserve and development of the hypothalamic-pituitary-ovarian axis. During reproductive years, maintaining an adequate ovarian reserve of follicles as well as balanced neuroendocrine control of reproductive organs is crucial for fertility. Dysregulation of either of these events, during development or in adulthood, can lead to reproductive disorders. Over the past five decades, human fertility rates have declined, whereas the incidence of female reproductive disorders has risen, trends partially linked to environmental factors such as exposure to endocrine-disrupting chemicals (EDCs). Here we outline epidemiological and mechanistic evidence for how EDCs affect the ovarian reserve during early development, its maintenance during adulthood and the establishment of the hypothalamic-pituitary control of puberty and ovulation. Our Review not only reveals strong support for the role of EDC exposure in the development of female reproductive disorders such as abnormal puberty, impaired fertility, premature menopause or polycystic ovarian syndrome, but also highlights knowledge gaps, including the difficulty to prove causality between exposure and human disease manifestation.

Gestational diabetes and its effect on fetal thymus size: a case-control study

INTRODUCTION

Fetal thymus size has recently been recognized as a sensitive parameter linked to pregnancy complications. This study investigates whether maternal diabetes affects fetal thymus size, potentially offering a means to identify at-risk fetuses before birth.

METHODS

This study was designed as a case-control study conducted from September 2023 to November 2024 in Iran. The study samples included 112 diabetic women (gestational diabetes or pre-pregnancy diabetes) as the case group and 112 healthy pregnant women attending the same hospital as the control group. Data were collected using a researcher-designed demographic questionnaire, and fetal thymus size was measured via abdominal ultrasound. Fetal thymus size is calculated using the thymic-thoracic ratio (TTR) and the thymus circumference.

RESULTS

A statistically significant difference was observed between the two groups regarding body mass index (BMI), an obstetric and demographic variable. The thymic-thoracic ratio (TTR) and the thymus circumference in diabetic pregnancies were statistically significantly lower than in the control group (p = 0.000). Odds ratios (95% CI) for the TTR index were 0.61 (CI 95%: 0.48 to 0.78), and thymus circumference was 0.95 (CI 95%: 0.93 to 0.97).

CONCLUSION

The present study indicated that a reduction in fetal thymus size may be associated with diabetes in pregnant women. However, it remains to be determined whether ultrasound evaluation of fetal thymus size can help predict perinatal outcomes in diabetic women.

Protective Effects of Phycobiliproteins from Arthrospira maxima (Spirulina) Against Cyclophosphamide-Induced Embryotoxicity and Genotoxicity in Pregnant CD1 Mice

Background/Objectives: In recent years the global incidence of cancer during pregnancy is rising, occurring in 1 out of every 1000 pregnancies. In this regard, the most used chemotherapy drugs to treat cancer are alkylating agents such as cyclophosphamide (Cp). Despite its great efficacy, has been associated with the production of oxidative stress and DNA damage, leading to embryotoxicity, genotoxicity, and teratogenicity in the developing conceptus. Therefore, this study aimed to investigate the protective role of phycobiliproteins (PBP) derived from Arthrospira maxima (spirulina) in reducing Cp-induced embryotoxicity and genotoxicity in pregnant CD1 mice. Methods: Pregnant CD1 mice were divided into five groups: control, Cp 20 mg/kg, and three doses of PBP (50, 100, and 200 mg/kg) + Cp co-treatment. PBP were administered orally from day 6 to 10.5 dpc, followed by a single intraperitoneal dose of Cp on 10.5 dpc. Embryos were collected at 12.5 dpc to assess morphological development and vascular alterations, while maternal DNA damage was evaluated using micronucleus assays and antioxidant enzyme activity in maternal plasma. Results: PBP exhibited a dose-dependent protective effect against Cp-induced damage. The 200 mg/kg PBP dose significantly reduced developmental abnormalities, micronucleated polychromatic erythrocytes, and oxidative stress, (as evidenced by increased SOD and GPx activity). Conclusions: Phycobiliproteins from Arthrospira maxima (spirulina) effectively reduced Cp-induced morphological and vascular alterations in embryos and genotoxicity in pregnant mice. These findings highlight their potential as a complementary therapy to mitigate teratogenic risks during chemotherapy. Further research is needed to optimize dosing and explore clinical applications.

Maternal and cord blood levels of metals and fetal liver function

Exposure to metals during pregnancy has been associated with adverse birth outcomes, but its impact on fetal liver function remains poorly understood. This study for the first time aimed to investigate the association between maternal and umbilical cord blood Metals levels and umbilical liver enzymes. A comprehensive analysis was conducted on 450 mother-newborn pairs in 2022, measuring 13 Metals in serum samples from pregnant women during the third trimester and umbilical cord blood samples. Regression analyses were utilized to examine the relationship between levels of maternal and umbilical cord blood Metals and the levels of gamma-glutamyl transferase (GGT), umbilical alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). G-comp analyses evaluated the combined effect of metals exposure on umbilical liver enzymes. Elevated levels of certain Metals in cord blood and maternal samples were positively linked with increased umbilical GGT, ALP, ALT, and AST levels. Notably, zinc (Zn) levels in cord blood exhibited an inverse correlation with umbilical liver enzyme levels. Furthermore, g-comp analyses revealed significant positive associations between exposure to metals mixtures and umbilical liver enzyme levels. An increase of one quartile in the mixture of maternal and umbilical Metals was linked with 99.45 U/L (95% CI:37.72, 161.19, p < 0.01), 2.79 (95% CI: 0.92, 4.65, p < 0.01), and 87.17 (95% CI: 53.96, 120.38, p < 0.01) increase in ALP, ALT and GGT levels. Further examination of the weight of Metals revealed As, Cd, Ni, Pb, Hg and Cr with the highest positive effects and Zn with the highest negative effect in the mixture effect on the umbilical liver enzyme. In summary, our results underscore the potential influence of prenatal heavy metal exposure on fetal liver function.

Elementomics of 32 elements in cord serum depicts the risk of orofacial clefts: A case-control study in Shanxi, China

Maternal exposure to various metallic and non-metallic elements has been linked to the occurrence of orofacial clefts (OFCs), yet there remains a dearth of comprehensive research on the potential ramifications of simultaneous exposure to multiple elements. In this study, we investigated the individual and combined effects of element exposure on OFCs in a cohort of 168 pregnant women (49 cases and 119 controls) in the Shanxi province of northern China from 2010 to 2015. Cord serum samples were obtained from all participants to analyze the levels of 32 elements using inductively coupled plasma-mass spectrometry. The study examined the independent correlation between element concentrations and OFCs using two machine screening models, Boruta and Least Absolute Shrinkage and Selection Operator. Bayesian kernel machine regression (BKMR) was utilized to determine the combined effects of key exposure elements on OFCs and to clarify the interaction between exposed elements through the generalized additive model (GAM). The screening models identified lead (Pb), tin (Sn), iron (Fe), and cesium (Cs) as the most significant risk factors for OFC development in offspring. In the BKMR model, the probability of OFCs increased with higher overall levels of these risk elements, with Pb emerging as the primary contributor to the combined effect of the mixture. The findings of the GAM indicated that the combined exposure to Pb and Sn had a synergistic effect on the risk of developing OFCs. Analysis of elemental exposure in umbilical cord serum suggested that Pb exposure may have detrimental effects on OFC development in offspring, which may be further intensified by a synergistic interaction between Sn and Pb in the occurrence of OFCs.

Associations of pentachlorophenol exposure during pregnancy with maternal and infant reproductive hormones based on a birth cohort

Pentachlorophenol (PCP), a typical environmental endocrine disruptor and a new persistent organic pollutant, has been extensively used as a pesticide worldwide. Although its use has been restricted for decades, PCP remains prevalent in both the environment and human bodies. Despite the known endocrine-disrupting and exogenous hormonal effects of PCP, few epidemiological studies examined such impact, especially among sensitive populations and during critical periods. Based on a prospective birth cohort in Wuhan, China, we collected maternal (first trimester; 13.0 ± 1.02 gestational weeks) and infant urine samples (1.16 ± 0.22 months postpartum) from 720 mother-infant pairs. We aimed to examine the association of PCP exposure during early pregnancy with maternal and infant urinary sex steroid hormones, including estrogens (estrone, E1; estradiol, E2; estriol, E3), progestogens (progesterone, P4; pregnenolone, P5; 17α-OH-Progesterone, 17OHP4; 17α-OH-Pregnenolone, 17OHP5), and androgens (testosterone, Testo; dihydrotestosterone, DHT; dehydroepiandrosterone, DHEA; androstenedione, A4). Additionally, gonadotropins [follicle-stimulating hormone (FSH) and luteinizing hormone (LH)] were measured in infant urine. Detection frequencies of all the sex steroid hormones in the maternal urine samples (>99 %) were higher than those in the infants' [most ≥80 %, except for E1 (3.36 %) and E2 (21.4 %)]. Maternal urinary PCP concentration was found to be significantly related with increased maternal sex steroid hormone concentrations; each interquartile increase in PCP concentration was positively related with percent change of the hormones (%Δ) ranging from 26.6 % to 48.5 %. On the other hand, maternal PCP exposure was associated with significantly increased P4 in male infants [%Δ (95 % confidence interval): 10.5 (0.56, 21.4)] but slightly decreased P4 in female infants [-11.9 (-21.8, 0.68)]. In addition, maternal PCP exposure was significantly associated with decreased FSH [%Δ (95 % CI): -9.90 (-17.0, -2.18)] and LH [-8.44 (-16.0, -0.19)] in the female infants, but not in the male infants. Sensitivity analyses, excluding infertility related treatment, pregnancy complications, preterm birth, or low birth weight, showed generally consistent results. Our findings implied that maternal/prenatal PCP exposure might disrupt the homeostasis of maternal and infant reproductive hormones. However, further studies are needed to confirm the findings.

Sub-Optimal Paternal Diet at the Time of Mating Disrupts Maternal Adaptations to Pregnancy in the Late Gestation Mouse

Pregnancy represents a stage during which maternal physiology and homeostatic regulation undergo dramatic change and adaptation. The fundamental purpose of these adaptations is to ensure the survival of her offspring through adequate nutrient provision and an environment that is tolerant to the semi-allogenic foetus. While poor maternal diet during pregnancy is associated with perturbed maternal adaptations during pregnancy, the influence of paternal diet on maternal well-being is less clearly defined. We fed C57BL/6 male mice either a control (CD), low protein diet (LPD), a high fat/sugar Western diet (WD) or the LPD or WD supplemented with methyl donors (MD-LPD and MD-WD, respectively) for a minimum of 8 weeks prior to mating with C57BL/6 females. Mated females were culled at day 17 of gestation for the analysis of maternal metabolic, gut, cardiac and bone health. Paternal diet had minimal influences on maternal serum and hepatic metabolite levels or gut microbiota diversity. However, analysis of the maternal hepatic transcriptome revealed distinct profiles of differential gene expression in response to the diet of the father. Paternal LPD and MD-LPD resulted in differential expression of genes associated with lipid metabolism, transcription, ubiquitin conjugation and immunity in dams, while paternal WD and MD-WD modified the expression of genes associated with ubiquitin conjugation and cardiac morphology. Finally, we observed changes in maternal femur length, volume of trabecular bone, trabecular connectivity, volume of the cortical medullar cavity and thickness of the cortical bone in response to the father's diets. Our current study demonstrates that poor paternal diet at the time of mating can influence the patterns of maternal metabolism and gestation-associated adaptations to her physiology.

E-Cigarette Exposure Alters Neuroinflammation Gene and Protein Expression in a Murine Model: Insights from Perinatally Exposed Offspring and Post-Birth Mothers

The use of E-cigarettes, often considered a safer alternative to traditional smoking, has been associated with high rates of cellular toxicity, genetic alterations, and inflammation. Neuroinflammatory impacts of cigarette smoking during pregnancy have been associated with increased risks of adverse childhood health outcomes; however, it is still relatively unknown if the same propensity is conferred on offspring by maternal vaping during gestation. Results from our previous mouse inhalation studies suggest such a connection. In this earlier study, pregnant C57BL/6 mice were exposed daily to inhaled E-cig aerosols (i.e., propylene glycol and vegetable glycerin, [PG/VG]), with or without nicotine (16 mg/mL) by whole-body inhalation throughout gestation (3 h/d; 5 d/week; total ~3-week) and continuing postnatally from post-natal day (PND) 4-21. As neuroinflammation is involved in the dysregulation of glucose homeostasis and weight gain, this study aimed to explore genes associated with these pathways in 1-mo.-old offspring (equivalent in humans to 12-18 years of age). Results in the offspring demonstrated a significant increase in glucose metabolism protein levels in both treatment groups compared to filtered air controls. Gene expression analysis in the hypothalamus of 1 mo. old offspring exposed perinatally to E-cig aerosols, with and without nicotine, revealed significantly increased gene expression changes in multiple genes associated with neuroinflammation. In a second proof-of-principal parallel study employing the same experimental design, we shifted our focus to the hippocampus of the postpartum mothers. We targeted the mRNA levels of several neurotrophic factors (NTFs) indicative of neuroinflammation. While there were suggestive changes in mRNA expression in this study, levels failed to reach statistical significance. These studies highlight the need for ongoing research on E-cig-induced alterations in neuroinflammatory pathways.