In assisted reproductive technology (ART), the aim of sperm cells’ preparation is to select competent spermatozoa with the highest fertilization potential and in this context, the intracytoplasmic sperm injection (ICSI) represents the most applied technique for fertilization. This makes the process of identifying the perfect spermatozoa extremely important. A number of methods have now been developed to mimic some of the natural selection processes that exist in the female reproductive tract. Although many studies have been conducted to identify the election technique, many doubts and disagreements still remain. In this review, we will discuss all the sperm cell selection techniques currently available for ICSI, starting from the most basic methodologies and continuing with those techniques suitable for sperm cells with reduced motility. Furthermore, different techniques that exploit some sperm membrane characteristics and the most advanced strategy for sperm selection based on microfluidics, will be examined. Finally, a new sperm selection method based on a micro swim-up directly on the ICSI dish will be analyzed. Eventually, advantages and disadvantages of each technique will be debated, trying to draw reasonable conclusions on their efficacy in order to establish the gold standard method.

The vaginal microbiota plays a critical role in the health of the female genital tract, and its composition contributes to gynecological disorders and infertility. Lactobacilli are the dominant species in the female genital tract: their production of lactic acid, hydrogen peroxide, and bacteriocins prevents the invasion and growth of pathogenic microorganisms. Several factors such as hormonal changes, age of reproduction, sexual practices, menstrual cycle, pregnancy, and antimicrobial drugs use can cause imbalance and dysbiosis of the vaginal microbiota. This review aims to highlight the impact of the vaginal microbiota in Assisted Reproductive Technology techniques (ART) and it examines the factors that influence the vaginal microbiota, the consequences of dysbiosis, and potential interventions to restore a healthy female genital tract.

Oocyte–cumulus cell interaction is essential for oocyte maturation and competence. The bidirectional crosstalk network mediated by gap junctions is fundamental for the metabolic cooperation between these cells. As cumulus cells exhibit a more glycolytic phenotype, they can provide metabolic substrates that the oocyte can use to produce ATP via oxidative phosphorylation. The impairment of mitochondrial activity plays a crucial role in ovarian aging and, thus, in fertility, determining the success or failure of assisted reproductive techniques. This review aims to deepen the knowledge about the electro-metabolic coupling of the cumulus–oocyte complex and to hypothesize a putative role of potassium channel modulators in order to improve fertility, promote intracellular Ca²⁺ influx, and increase the mitochondrial biogenesis and resulting ATP levels in cumulus cells.

With infertility populations rapidly aging, treatments improving pregnancy chances assume increasing clinical importance. Dehydroepiandrosterone (DHEA) has been reported to improve pregnancy rates and lower miscarriage rates in women with diminished ovarian function. This study was planned to evaluate whether pretreatment with DHEA may improve in vitro fertilization (IVF) parameters and pregnancy outcomes in infertile women with advanced reproductive age and normal ovarian reserve. In this double-blind, randomized, placebo-controlled study, 109 infertile patients aging 36–40 years old were selected to undergo the long protocol IVF. Eight weeks before starting the IVF cycle and during treatment, patients in Group 1 received 75 mg of DHEA once a day; patients in control group (Group 2) received placebo. The primary endpoint of the study was number of clinical pregnancy, live birth and miscarriage rates; secondary endpoint was modification of standard IVF parameters, including stimulation duration (days of rhFSH administration), E2 on HCG-day, endometrial thickness, number of retrieved oocytes, metaphase II oocytes, number of transferred embryos and score of leading embryos transferred. Patients in the DHEA group had a significantly higher live birth rate compared with controls (P < 0.05). Conversely, miscarriage rate was higher for patients in the control group (P < 0.05). DHEA supplementation may significantly improve IVF outcomes in infertile women with advanced reproductive age and normal ovarian reserve.