Effects of Low Luteinizing Hormone Serum Levels on Oocyte Retrieval, Fertilization Rate, and Embryo Quality during Controlled Ovarian Stimulation: Results from a Prospective Cohort Analysis.

OBJECTIVES: Luteinizing hormone (LH) plays a key role in normal follicular development and oocyte maturation in controlled ovarian stimulation. LH stimulates the proliferation and differentiation of theca cells for the secretion of androgens, synergistically increasing estrogen production. This study aimed to investigate the effects of low LH concentrations on oocyte retrieval, fertilization, and embryo development in patients undergoing in vitro fertilization/intracytoplasmic sperm injection. DESIGN: We prospectively (ClinicalTrials ID: NCT05755529) analyzed patients undergoing in vitro fertilization/intracytoplasmic sperm injection, subdividing them into three groups according to their age. Serum LH levels were evaluated on day 3, during stimulation (day 10) and before ovulation induction (day 12). PARTICIPANTS/MATERIALS, SETTING, METHODS: Forty-three consecutive women were scheduled for IVF and received ovarian stimulation with follitropin alfa (Gonal F, Merck Serono, Germany) and ganirelix (Fyremaldel, Sun Pharma, Italy). Statistical analysis was performed with InStat 3.10, GraphPad software, San Diego, CA, USA. Normal distribution was tested by the Shapiro-Wilk test. Continuous variables were expressed as the mean and standard deviation. Categorical variables are expressed as frequencies and percentages. RESULTS: Our data analysis suggests that serum LH levels progressively decrease during controlled ovarian stimulation, and this effect is more evident in the early phase of this procedure. From this perspective, circulating LH levels may significantly decrease during the late follicular phase due to the negative feedback of ovarian hormones from multiple follicular developments or after the suppressive effects of gonadotropin-releasing hormone antagonists. LIMITATIONS: Although our study confirms that exogenous LH can be considered a strategy in women with reduced LH levels during ovarian stimulation to improve oocyte quality and reproductive outcome, the generalizability of the results is limited by the low number of participants enrolled. CONCLUSIONS: Exogenous LH may be considered a strategy in women with a decrease in LH levels during ovarian stimulation to improve oocyte quality and reproductive outcome.

In Vitro Nano-Polystyrene Toxicity: Metabolic Dysfunctions and Cytoprotective Responses of Human Spermatozoa.

The ubiquitous spread of Polystyrene nanoplastics (PS-NPs) has rendered chronic human exposure an unavoidable phenomenon. The biodistribution of such particles leads to bioaccumulation in target organs including the testis, the site of sperm maturation. The purpose of this research has been to estimate the impact of PS-NPs (50 and 100 nm) on the metabolism of mature spermatozoa. The analysis of the semen parameters has revealed a higher toxicity of the smaller sized PS-NPs, which have negatively affected major organelles, leading to increased acrosomal damage, oxidative stress with the production of ROS, DNA fragmentation, and decreased mitochondrial activity. PS-NPs of 100 nm, on the other hand, have mainly affected the acrosome and induced a general state of stress. An attempt has also been made to highlight possible protective mechanisms such as the expression of HSP70s and their correlation among various parameters. The results have evinced a marked production of HSP70s in the samples exposed to the smaller PS-NPs, negatively correlated with the worsening in oxidative stress, DNA fragmentation, and mitochondrial anomalies. In conclusion, our results have confirmed the toxicity of PS-NPs on human spermatozoa but have also demonstrated the presence of mechanisms capable of counteracting at least in part these injuries.

Antioxidant activity of two Opuntia Mill. species fruit extracts on human sperm quality after a freeze-thaw cycle.

This study investigated the phenolic compounds and antioxidant capacity of fruit extracts of Opuntia dillenii (Ker Gawl.) Haw.(OD) and Opuntia ficus-indica (L.) Mill.(OFI), yellow (F1) and red (F2) varieties. In order to evaluate the antioxidant activity of these extracts on human sperm quality after thawing, the semen parameters (vitality, motility, acrosome reaction, oxidative stress, and DNA fragmentation) were analysed after 1 h of exposure. The results showed that OD has higher phenolic content and antioxidant power than OFI, and that they are higher in F2 than F1. Furthermore, regarding the activity of extracts on thawed sperm, the results showed a significant increase in motility in samples treated with OFI F1 and OD extracts, while an improvement in vitality and acrosome reaction and a reduction of DNA fragmentation were observed in all exposed samples compared to the control. Finally, a reduction of oxidative stress was observed in samples exposed to OFI F2 and OD than control.