Human Reproduction
Audio Summaries

Heat exposure during susceptible windows of spermatogenesis and sperm epigenetic age

Mar 24, 2026

The authors investigate whether preconception exposure to outdoor heat stress during spermatogenesis affects sperm epigenetic age in men undergoing infertility treatment. They find that increased exposure to high wet bulb temperatures during critical stages of spermatogenesis is associated with accelerated sperm epigenetic age, suggesting that heat stress may negatively impact men's reproductive health. The study highlights the potential implications of environmental temperature on sperm DNA methylation and fertility outcomes.

Human stem cell-based embryo models: innovation, ethics, and policy

Mar 24, 2026

The authors aim to establish a foundational framework for research, technological development, and regulation in the emerging field of stem cell-based embryo models (SCBEMs), which are designed to mimic early human development. They seek to address the potential applications of SCBEMs in understanding embryo development and addressing health challenges, while also highlighting the ethical and legal implications that arise from this innovative research. The paper serves as a consensus document reflecting the views of a group of researchers, providing guidance for future work in this area.

How big is the time window for cell-free fetal DNA testing after pregnancy loss and which factors are associated with a successful result?

Mar 24, 2026

The authors investigate the decline of cell-free fetal DNA (cffDNA) following early pregnancy loss and the factors influencing its detectability. They find that cffDNA levels can remain detectable for up to three days post-tissue passage, with higher β-hCG levels correlating with increased odds of obtaining a conclusive test result. These findings suggest a need for refined cffDNA diagnostics to improve reproductive care and decision-making after pregnancy loss.

Early pregnancy concentrations of pregnancy-associated plasma protein-A (PAPP-A) and insulin-like growth factor-1 (IGF-1) following frozen embryo transfer: secondary analyses from a randomized controlled trial

Mar 24, 2026

The authors aimed to determine whether maternal concentrations of pregnancy-associated plasma protein-A (PAPP-A) and insulin-like growth factor-1 (IGF-1) are influenced by the frozen embryo transfer (FET) protocol during early pregnancy. They found that women undergoing programmed cycle (PC) FET had significantly lower levels of both PAPP-A and IGF-1 compared to those in modified natural cycle (mNC) and gonadotrophin-stimulated cycle (gSC) FETs, suggesting that PC-FET may alter early placental function and contribute to increased obstetric risks.

Ovarian and reproductive hormone characteristics and risk of cycle cancellation in immediate versus postponed modified natural cycle frozen embryo transfer (mNC-FET) cycles

Mar 23, 2026

This study investigates whether ovarian and reproductive hormone characteristics, as well as the risk of cycle cancellation, differ between immediate and postponed modified natural cycle frozen embryo transfer (mNC-FET) cycles. The findings indicate significant differences in ovarian morphology, hormone levels, and follicular phase length between the two approaches, with a higher but not statistically significant cancellation rate in immediate cycles. These results raise concerns about the clinical feasibility of immediate FET treatment following ovarian stimulation.

Periconceptional ultra-processed food consumption in women and men, fertility, and early embryonic development

Mar 23, 2026

The study investigates the association between periconceptional ultra-processed food (UPF) consumption in both women and men and its effects on fertility, embryonic growth, and yolk sac development. The findings indicate that higher maternal UPF intake is linked to reduced embryonic growth and yolk sac volume, while increased paternal UPF consumption correlates with lower fertility rates. These results highlight the importance of dietary patterns during the preconception period for reproductive outcomes and early embryonic development.

Depression and anxiety among women going through medically assisted reproduction: a register-based cohort study

Mar 23, 2026

The study investigates how the incidence and prevalence of depression and anxiety change for women undergoing medically assisted reproduction (MAR) over a three-year period before and after treatment initiation. The findings reveal a decline in mental health issues prior to treatment, followed by an increase post-treatment, with levels returning to pre-treatment status after three years. This suggests that mental health support may be particularly important during specific phases of the MAR process.

A clinical protocol for the detection of comorbidities associated with monogenic causes of male infertility

Mar 21, 2026

The authors aimed to establish a systematic framework for identifying comorbidities associated with monogenic causes of male infertility. They developed a seven-step protocol to generate gene-specific phenotyping for two men with infertility linked to the genes MEI1 and DNAH17, assessing potential health risks through targeted questionnaires and clinical tests. While initial results showed no significant comorbidities, the authors emphasize the need for further phenotyping of additional patients to confirm these findings.

From tablets to targeted therapy: the APHRODITE era in male infertility

Mar 21, 2026

The authors explore whether the newly proposed APHRODITE criteria can improve the treatment of idiopathic male infertility by transitioning from empirical oral therapies to targeted gonadotropin therapy. They argue that this biologically driven approach, akin to advancements in ovarian stimulation for IVF, may enhance treatment outcomes by better aligning interventions with individual hormonal profiles. The article emphasizes the need for future prospective trials to validate the effectiveness of these criteria and compare the efficacy of traditional oral agents with injectable gonadotropins.

CD138 expression in the endometrium associates with endometrial timing and inflammatory status but not microbiota composition

Mar 20, 2026

The authors investigate the relationship between CD138 expression in the endometrium and the composition of the reproductive tract microbiota in women with a history of recurrent pregnancy loss. They find that while CD138+ cells in the endometrial stroma are cycle-dependent and associated with impaired endometrial timing, there is no significant correlation with the microbiota composition. This challenges the previously assumed link between CD138+ chronic endometritis and adverse reproductive outcomes, suggesting that CD138 levels are not influenced by bacterial factors and are more indicative of endometrial immaturity.