Publications by authors named "Samantha B Schon"
Obesity is a highly prevalent chronic disease that impacts >40% of reproductive-aged females. The pathophysiology of obesity is complex and can be understood simply as a chronic energy imbalance whereby caloric intake exceeds caloric expenditure with an energy surplus stored in adipose tissue. Obesity may be categorized into degrees of severity as well as different phenotypes on the basis of metabolic health and underlying pathophysiology.
View Article and Find Full Text PDFObjective: To perform a comprehensive assessment of protamine (P) isoforms and modifications in human sperm with the aim of identifying how P modifications and isoforms are altered in men with reduced sperm motility and low sperm count.
Design: Cross-sectional.
Setting: Academic medical center.
Obesity is a highly prevalent chronic disease with a significant effect on reproductive-age women. The clinical implications of obesity on fertility and pregnancy are well studied citing ovulatory dysfunction, hormonal imbalances, higher miscarriage rates, and increased maternal and neonatal risks. For this reason, many patients with obesity seek reproductive specialists to help build their families.
View Article and Find Full Text PDFConventional dogma presumes that protamine-mediated DNA compaction in sperm is achieved by electrostatic interactions between DNA and the arginine-rich core of protamines. Phylogenetic analysis reveals several non-arginine residues conserved within, but not across species. The significance of these residues and their post-translational modifications are poorly understood.
View Article and Find Full Text PDFObjective: To report a unique case of total fertilization failure (TFF) after in vitro fertilization with intracytoplasmic sperm injection related to homozygous gene mutation and summarize the current literature and management of TFF.
Design: Case report.
Setting: Academic fertility center.
Objective: To compare the proteomic composition of follicular fluid from women with normal weight vs. women with obesity but without a history of polycystic ovary syndrome or known ovarian dysfunction undergoing in vitro fertilization.
Design: Cross-sectional.
Article Synopsis
- Ovarian hyperstimulation syndrome (OHSS) is a serious but rare complication of fertility treatments, and while efforts have been made to reduce its incidence, it remains unclear if these efforts have changed how often patients seek emergency treatment.
- A study over ten years (2006-2016) found that although the number of ovarian stimulation cycles increased, the rate of OHSS-related emergency department visits stayed stable, while admission rates for severe cases decreased significantly.
- The cost of treating OHSS in emergency departments nearly doubled during the same period, indicating a possible change in how OHSS is managed or its overall severity among patients.
Objective: Despite obesity's significant impact on reproduction, its influence on the physiology of the human endometrium is largely understudied. We hypothesized that endometrial proteomic differences exist between obese (OW; body mass index [BMI] ≥30 kg/m) and normal-weight women (NWW; BMI, 18.5-24.
View Article and Find Full Text PDFUnexplained infertility affects about one-third of infertile couples and is defined as the failure to identify the cause of infertility despite extensive evaluation of the male and female partners. Therefore, there is a need for a multiparametric approach to study sperm function. Recently, we developed a Fluorescence-Based Ratiometric Analysis of Sperm Centrioles (FRAC) assay to determine sperm centriole quality.
View Article and Find Full Text PDFArticle Synopsis
- - There has been a notable rise in assisted reproductive therapies (ARTs), enabling many infertile couples to conceive, but these techniques may also lead to epigenetic risks affecting the health of gametes and embryos, with potential long-term consequences.
- - Research has been conducted to understand the molecular mechanisms behind these ART-induced epigenetic changes using human and animal models, while highlighting the ethical responsibilities of researchers and embryologists regarding the perceived unnaturalness of ART procedures.
- - The discussion includes the moral implications of human embryo research, the ethical use of model systems to study embryogenesis, and the controversial 14-day culture limit for human embryos, suggesting that scientific inquiry should continue as long as ethical boundaries are respected.
Fallopian tube (FT) homeostasis requires dynamic regulation of heterogeneous cell populations and is disrupted in infertility and ovarian cancer. Here, we applied single-cell RNA-seq to profile 59,738 FT cells from four healthy, pre-menopausal subjects. The resulting cell atlas contains 12 major cell types representing epithelial, stromal, and immune compartments.
View Article and Find Full Text PDFObjective: To determine the implications of an incidentally noted subchorionic hematoma on pregnancy outcomes in the infertile population.
Methods: Retrospective cohort study at a tertiary care, university-based facility. All patients with intrauterine pregnancy on initial obstetric ultrasound presenting to an infertility clinic between January 2015 and March 2018 (n = 1210), regardless of treatment cycle, were included.
Purpose: To report experience designing and establishing a reproductive registry and sample biorepository and to describe initial subject characteristics and biospecimens.
Methods: Beginning in December 2017, patients presenting for reproductive care at the University of Michigan were approached for study enrollment. Following consent, subjects completed detailed reproductive and health questionnaires.
Article Synopsis
- Asherman syndrome is a reproductive disorder marked by intrauterine adhesions, resulting in symptoms like amenorrhea, infertility, and pregnancy complications.
- Treatment typically involves a surgical procedure called hysteroscopic lysis of adhesions.
- Post-surgery, methods like hormone therapy and barrier gels are used to reduce the risk of adhesions returning, but there's a lack of strong evidence to back their effectiveness, indicating a need for further research.
Purpose: Alternations to the paternal epigenome, specifically the components of sperm chromatin, can lead to infertility in humans and potentially transmit aberrant information to the embryo. One key component of sperm chromatin is the post-translational modification of histones (PTMs). We previously identified a comprehensive profile of histone PTMs in normozoospermic sperm; however, only specific histone PTMs have been identified in abnormal sperm by antibody-based approaches and comprehensive changes to histone PTM profiles remain unknown.
View Article and Find Full Text PDFPurpose: The purpose of this study was to compare baseline characteristics and ovarian stimulation outcomes between patients presenting for medically indicated vs. elective fertility preservation consultation and to determine the impact of the 2013 ASRM guidelines on oocyte cryopreservation on the patient population presenting for fertility preservation consultation.
Methods: Retrospective cohort study conducted at an academic center.
Background: During the process of spermatogenesis, male germ cells undergo dramatic chromatin reorganization, whereby most histones are replaced by protamines, as part of the pathway to compact the genome into the small nuclear volume of the sperm head. Remarkably, approximately 90 % (human) to 95 % (mouse) of histones are evicted during the process. An intriguing hypothesis is that post-translational modifications (PTMs) decorating histones play a critical role in epigenetic regulation of spermatogenesis and embryonic development following fertilization.
View Article and Find Full Text PDFArticle Synopsis
- - This study investigates the factors that predict inadequate endometrial cavity thickness (less than 8 mm) during frozen embryo transfer (FET) cycles among 274 women who had their first endometrial preparation with estradiol.
- - The research found that factors such as lower body mass index, nulliparity, previous hysteroscopy, and thinner endometrial lining in fresh cycles were linked to inadequate thickness in FET cycles, while age and duration of estrogen treatment were not.
- - A fresh cycle endometrial thickness of 11.5 mm or less is a significant indicator for potential issues in a subsequent FET cycle, suggesting that women in this category may need extra support to achieve appropriate endometrial