BACKGROUND The global increase in frozen-thawed embryo transfer (FET) cycles has led to a critical evaluation of endometrial preparation methods. While various approaches such as natural or modified natural cycle FET, stimulated FET by use of letrozole (LTZ) and/or gonadotrophins, and artificial cycle (AC) FET, are currently in clinical use, the optimal regimen remains unclear, particularly for women

BACKGROUND Male germline stem cells are relevant for stem cell researchers but also for andrologists as they are crucial for testis function and initiation/maintenance of spermatogenesis. They are also considered a target for fertility preservation in the male; e.g. germ cell transplantation or testicular grafting rely on spermatogonial stem cells (SSCs) and may soon become clinical tools to recover

BACKGROUND Women are increasingly choosing to delay childbirth, and those with low ovarian reserves indicative of primary ovarian insufficiency are at risk for sub- and infertility and also the early onset of menopause. Experimental strategies that promise to extend the duration of ovarian function in women are currently being developed. One strategy is to slow the rate of loss of existing primordial

BACKGROUND Dissecting the key molecular mechanism of embryonic development provides novel insights into embryogenesis and potential intervention strategies for clinical practices. However, the ability to study the molecular mechanisms of early embryo development in humans, such as zygotic genome activation and lineage segregation, is meaningfully constrained by methodological limitations and ethical

BACKGROUND RNA modifications, collectively known as the epitranscriptome, represent the third layer of gene regulation, influencing gene expression at transcriptional, post-transcriptional, and translational levels. RNA-modifying proteins (RMPs), including writers, erasers, and readers, are responsible for depositing, removing, and recognizing chemical modifications on RNA molecules. These modifications

BACKGROUND The advent of organoid culture systems has revolutionized our ability to model and study complex tissues in vitro. The placenta is one of the last human organs to have a functional organoid model developed: trophoblast organoids. These 3-dimensional structures, derived from placental tissue, offer researchers a valuable tool for studying previously inaccessible processes that occur within

Mitochondrial DNA (mtDNA) diseases pose unique challenges for genetic counselling and require tailored approaches to address recurrence risks and reproductive options. The intricate dynamics of mtDNA segregation and heteroplasmy shift significantly impact the chances of having affected children. In addition to natural pregnancy, oocyte donation, and adoption, IVF-based approaches can reduce the risk

BACKGROUND Sperm head shaping, controlled by the acrosome-acroplaxome-manchette complex, represents a significant morphological change during spermiogenesis and involves numerous proteins expressed in a spatially and temporally specific manner. Defects in sperm head shaping frequently lead to teratozoospermia concomitant with oligozoospermia and asthenozoospermia, but the pathogenic mechanism underlying

BACKGROUND Ovarian aging occurs earlier than the aging of many other organs and has a lasting impact on women’s overall health and well-being. However, effective interventions to slow ovarian aging remain limited, primarily due to an incomplete understanding of the underlying molecular mechanisms and drug targets. Recent advances in omics data resources, combined with innovative computational tools

INTRODUCTION The embryonic period in human development is the foundation of lifelong and even transgenerational health. Although previously believed to be uniform, there is increasing evidence that embryonic growth is influenced by the conditions and modifiable lifestyle factors of parents in the periconception period. In ongoing pregnancies, a delay in growth in the first trimester has been associated

BACKGROUND mRNA splicing is a fundamental process in the reproductive system, playing a pivotal role in reproductive development and endocrine function, and ensuring the proper execution of meiosis, mitosis, and gamete function. Trans-acting factors and cis-acting elements are key players in mRNA splicing whose dysfunction can potentially lead to male and female infertility. Although hundreds of trans-acting

BACKGROUND Transgender and gender diverse (TGD) people seek gender-affirming care at any age to manage gender identities or expressions that differ from their birth gender. Gender-affirming hormone treatment (GAHT) and gender-affirming surgery may alter reproductive function and/or anatomy, limiting future reproductive options to varying degrees, if individuals desire to either give birth or become

BACKGROUND The ovarian response to gonadotropin stimulation varies widely among women, and could impact the probability of live birth as well as treatment risks. Many studies have evaluated the impact of different gonadotropin starting doses, mainly based on predictive variables like ovarian reserve tests (ORT) including anti-Müllerian hormone (AMH), antral follicle count (AFC), and basal follicle-stimulating

BACKGROUND Varicocele is an abnormal dilation and torsion of the pampiniform venous plexus in the scrotum due to venous reflux, primarily affecting the left side. It affects 15% of men and is a prevalent contributor to male infertility. Varicocele is a complex disorder influenced by genetic, epigenetic, and environmental factors. Epigenetic modifications, which regulate genome activity independently

BACKGROUND Successful implantation is a critical step for embryo survival. The major losses in natural and assisted human reproduction appeared to occur during the peri-implantation period. Because of ethical constraints, the fascinating maternal–fetal crosstalk during human implantation is difficult to study and thus, the possibility for clinical intervention is still limited. OBJECTIVE AND RATIONALE

BACKGROUND To prevent the transfer of embryos affected by monogenic conditions and/or chromosomal defects, preimplantation genetic testing (PGT) requires trophectoderm biopsy and cryopreservation. In 2–6% of biopsies, the diagnosis may be inconclusive due to DNA amplification failure or low-quality results. In these cases, a round of re-warming, re-biopsy, and re-cryopreservation is required to obtain

BACKGROUND Functional hypothalamic amenorrhoea (FHA) is responsible for 20–35% of all cases of secondary amenorrhoea and, thus, is the second most common cause of secondary amenorrhoea after polycystic ovary syndrome (PCOS). A high number of patients with FHA reveal polycystic ovarian morphology (PCOM) on ultrasound. The combination of amenorrhoea and PCOM can lead to confusion. First, amenorrhoeic

BACKGROUND Studies have inconsistently observed that children conceived by IVF or ICSI have higher blood pressure compared to children not conceived by these ARTs. OBJECTIVE AND RATIONALE The aim was to perform a systematic review and meta-analysis of blood pressure measures of offspring conceived by ART and those conceived naturally. Resolving the suspicion of ART as a risk factor of higher blood

BACKGROUND Successful ovulation is essential for natural conception and fertility. Defects in the ovulatory process are associated with various conditions of infertility or subfertility in women. However, our understanding of the intra-ovarian biochemical mechanisms underlying this process in women has lagged compared to our understanding of animal models. This has been largely due to the limited availability

BACKGROUND Biochemical hyperandrogenism is a hallmark and diagnostic feature of polycystic ovary syndrome (PCOS). However, the most accurate androgen measurement for assessing biochemical hyperandrogenism in PCOS diagnosis remains uncertain. OBJECTIVE AND RATIONALE This systematic review aimed to assess different androgen measures [including total testosterone (TT), calculated free testosterone (cFT)

BACKGROUND Intermittent fasting, such as during Ramadan, is prevalent among pregnant women. However, the association between Ramadan during pregnancy and offspring health along the life course has not been fully established. OBJECTIVE AND RATIONALE Fetal programming research indicates that prenatal exposures, particularly during early pregnancy, can cause long-term structural and physiological changes

BACKGROUND Bisphenol A (BPA) is an endocrine disrupting chemical released from plastic materials, including food packaging and dental sealants, persisting in the environment and ubiquitously contaminating ecosystems and human populations. BPA can elicit an array of damaging health effects and, alarmingly, ‘BPA-free’ alternatives mirror these harmful effects. Bisphenol exposure can negatively impact

BACKGROUND Women with endometriosis may constitute a group at a particularly increased risk of pregnancy-related complications. Furthermore, women selected for assisted reproductive technology (ART) are exposed to additional endocrinological and embryological factors that have been associated with adverse pregnancy outcomes. OBJECTIVE AND RATIONALE This study aimed to investigate the independent effect

BACKGROUND Fibrosis is an important pathological feature of endometriotic lesions of all subtypes. Fibrosis is present in and around endometriotic lesions, and a central role in its development is played by myofibroblasts, which are cells derived mainly after epithelial-to-mesenchymal transition (EMT) and fibroblast-to-myofibroblast transdifferentiation (FMT). Transforming growth factor-β (TGF-β) has

BACKGROUNDChemotherapy-associated ovarian damage (CAOD) is one of the most feared short- and long-term side effects of anticancer treatment in premenopausal women. Accumulating detailed data show that different chemotherapy regimens can lead to disturbance of ovarian hormone levels, reduced or lost fertility, and an increased risk of early menopause. Previous studies have often focused on the direct

BACKGROUND Monozygotic (MZ) twins are believed to arise from the fission of a single fertilized embryo at different stages. Monochorionic MZ twins, who share one chorion, originate from the splitting of the inner cell mass (ICM) within a single blastocyst. In the classic model for dichorionic MZ twins, the embryo splits before compaction, developing into two blastocysts. However, there are a growing

BACKGROUND The genetic composition of embryos generated by in vitro fertilization (IVF) can be examined with preimplantation genetic testing (PGT). Until recently, PGT was limited to detecting single-gene, high-risk pathogenic variants, large structural variants, and aneuploidy. Recent advances have made genome-wide genotyping of IVF embryos feasible and affordable, raising the possibility of screening

BACKGROUND The establishment and maintenance of pregnancy depend on endometrial competence. Asherman syndrome (AS) and intrauterine adhesions (IUA), or endometrial atrophy (EA) and thin endometrium (TE), can either originate autonomously or arise as a result from conditions (i.e. endometritis or congenital hypoplasia), or medical interventions (e.g. surgeries, hormonal therapies, uterine curettage

BACKGROUNDWhile there is a recognized role of optimizing lifestyle (diet and physical activity) behaviours in the management of infertility, the best practice remains unknown and factors influencing the lifestyle of people with infertility are not well understood.OBJECTIVE AND RATIONALEThis systematic review evaluated barriers and enablers to a healthy lifestyle in people with infertility, from the

BACKGROUND Awareness of the age-related decline in fertility potential has increased the popularity of planned oocyte cryopreservation (POC). However, data regarding outcomes of POC, including rates of women returning to thaw oocytes, as well as pregnancy and live birth rates, are scarce and based mostly on small case series. OBJECTIVE AND RATIONALE POC was defined as cryopreservation exclusively for

BACKGROUNDThe increasing prevalence of obesity worldwide poses a significant threat to reproductive function owing, in part, to hormonal disturbances caused by negative feedback between excess adiposity and the hypothalamic–pituitary–ovarian axis. Consequently, finding the most appropriate strategies to lose weight and improve ovulation in women with overweight or obesity is a clinically relevant matter

BACKGROUNDDisclosure of donor conception has been advocated in several jurisdictions in recent years, especially in those that practice identity-release donation. However, research on disclosure decisions has not been consolidated systematically in the last 10 years to review if parents are telling and what factors may be impacting their decisions.OBJECTIVE AND RATIONALEAre parents disclosing to their

BACKGROUND The placenta is a unique and pivotal organ in reproduction, controlling crucial growth and cell differentiation processes that ensure a successful pregnancy. Placental development is a tightly regulated and dynamic process, in which the transforming growth factor beta (TGFβ) superfamily plays a central role. This family of pleiotropic growth factors is heavily involved in regulating various

BACKGROUND With increasing significance of developmental programming effects associated with placental dysfunction, more investigations are devoted to improving the characterization and understanding of placental signatures in health and disease. The placenta is a transitory but dynamic organ adapting to the shifting demands of fetal development and available resources of the maternal supply throughout

BACKGROUND Girls with Turner syndrome (TS) lack a partial or complete sex chromosome, which causes an accelerated decline of their ovarian reserve. Girls have to deal with several dilemmas related to their fertility, while only a limited number of them are referred to a fertility specialist and counselled about options of family planning on time. OBJECTIVE AND RATIONALE This scoping review provides

BACKGROUND Family-planning policies have focused on contraceptive approaches to avoid unintended pregnancies, postpone, or terminate pregnancies and mitigate population growth. These policies have contributed to significantly slowing world population growth. Presently, half the countries worldwide exhibit a fertility rate below replacement level. Not including the effects of migration, many countries

BACKGROUND The World Health Organization (WHO) system for the classification of disorders of ovulation was produced 50 years ago and, by international consensus, has been updated by the International Federation of Gynecology and Obstetrics (FIGO). OBJECTIVE AND RATIONALE This review outlines in detail each component of the FIGO HyPO-P (hypothalamic, pituitary, ovarian, PCOS) classification with a concise

BACKGROUND Levels of anti-Müllerian hormone (AMH) are known to be associated with lifestyle determinants such as smoking and oral contraception (OC) use. When measuring AMH in clinical practice, it is essential to know which factors may influence circulating levels or ovarian reserve in general. OBJECTIVE AND RATIONALE To date, there is no systematic review or summarizing consensus of the nature and

BACKGROUND ART is associated with higher rates of twin pregnancies than singleton pregnancies. Whether twin pregnancies conceived following ART have additional maternal and neonatal complications compared with non-ART twin pregnancies is not known. OBJECTIVE AND RATIONALE The objective was to quantify the risk of adverse maternal and perinatal outcomes among twin pregnancies conceived following ART

BACKGROUND ART differs in effectiveness, side-effects, administration, and costs. To improve the decision-making process, we need to understand what factors patients consider to be most important. OBJECTIVE AND RATIONALE We conducted this systematic review to assess which aspects of ART treatment (effectiveness, safety, burden, costs, patient-centeredness, and genetic parenthood) are most important

BACKGROUND Polycystic ovary syndrome (PCOS) is a common and distressing endocrine disorder associated with lower quality of life, subfertility, diabetes, cardiovascular disease, depression, anxiety, and eating disorders. PCOS characteristics, its comorbidities, and its treatment can potentially influence sexual function. However, studies on sexual function in women with PCOS are limited and contradictory

BACKGROUND The last decade has seen increased research on the relationship between diet and male fertility, but there are no clearly defined nutritional recommendations for men in the preconception period to support clinical fertility outcomes. OBJECTIVE AND RATIONALE The purpose of this scoping review is to examine the extent and range of research undertaken to evaluate the effect(s) of diet in the

BACKGROUND Millions of children have been born throughout the world thanks to ARTs, the harmlessness of which has not yet been fully demonstrated. For years, efforts to evaluate the specific effects of ART have focused on the embryo; however, it is the oocyte quality that mainly dictates first and foremost the developmental potential of the future embryo. Ovarian stimulation, cryopreservation, and

BACKGROUND IVF and IUI with ovarian stimulation (IUI-OS) are widely used in managing unexplained infertility. IUI-OS is generally considered first-line therapy, followed by IVF only if IUI-OS is unsuccessful after several attempts. However, there is a growing interest in using IVF for immediate treatment because it is believed to lead to higher live birth rates and shorter time to pregnancy. OBJECTIVE

BACKGROUND During the human menstrual cycle and pregnancy, the endometrium undergoes a series of dynamic remodeling processes to adapt to physiological changes. Insufficient endometrial remodeling, characterized by inadequate endometrial proliferation, decidualization and spiral artery remodeling, is associated with infertility, endometriosis, dysfunctional uterine bleeding, and pregnancy-related complications

BACKGROUND Pregnant women infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are more likely to experience preterm birth and their neonates are more likely to be stillborn or admitted to a neonatal unit. The World Health Organization declared in May 2023 an end to the coronavirus disease 2019 (COVID-19) pandemic as a global health emergency. However, pregnant women are still

BACKGROUND The Endometriosis Health Profiles (EHPs), the EHP-30 and EHP-5, are patient-reported outcome measures that were developed to measure the health-related quality of life (HRQoL) of women living with endometriosis. Prior to their development, a systematic review was undertaken which identified that the HRQoL of women living with endometriosis was poorly understood, with only three medical and

BACKGROUND Polycystic ovary morphology (PCOM) on ultrasonography is considered as a cardinal feature of polycystic ovarian syndrome (PCOS). Its relevance as a diagnostic criterion for PCOS was reaffirmed in the most recent International Evidence-Based Guideline for the Assessment and Management of PCOS. However, there remains a lack of clarity regarding the best practices and specific ultrasonographic