The aim of this overview is to discuss the current information about the search for the optimum yield of gametes in assisted reproduction, as one of the major pillars of IVF success. The first topic is focused on the number of male gametes and the possible impact of some genetic traits on these parameters. The number of spermatozoa did not seem to be crucial when there is no severe male factor of infertility. Genetic testing prior to using those sperm cells is very important. Different methods were applied in order to elect the "best" spermatozoa according to specific indications. The next problem discussed is the importance of the number of oocytes collected. Several studies have agreed that "15 oocytes is the perfect number," as the number of mature oocytes is more important. However, if elective single embryo transfer is performed, the optimal number of oocytes will enable a proper embryo selection. The third problem discussed concerns fertility preservation. Many educational programs promote and encourage procreation at maternal ages between 20-35 years, since assisted reproduction is unable to fully overcome the effects of female aging and fertility loss after that age. It is also strongly recommended to ensure a reasonable number of cryopreserved mature oocytes, preferably in younger ages (<35), for which an average of two stimulation cycles are likely required. For embryo cryopreservation, the "freeze all" strategy suggests the vitrification of good embryos, therefore quality is prior to number and patient recruitment for this strategy should be performed cautiously.

Sperm abnormalities are a major factor of human infertility. Since 1987, there are several references in different editions of World Health Organization (WHO) manual defining optimal sperm parameters. Over the years, many reproductive specialists have been constantly debating, suggesting and remodeling the frame values in those guidelines. Semen parameters have a leading role both in natural conception and assisted reproduction technologies (ART) outcomes. Deviations expressed in lower sperm count, impaired motility, abnormal morphology, and high percentage of sperm DNA fragmentation are linked to reduced chances to achieve pregnancy. In cases with low sperm count, severe oligoasthenozoospermia (OA) or azoospermia, karyotyping or evaluation with sperm aneuploidy test (SAT) could be an option and genetic counseling will be necessary if there is an obvious deviation or aberration (e.g., translocation, aneuploidy, etc.). Taking care of lifestyle factors as body mass index (BMI), diets, alcohol intake, smoking, using some additional nutrition and vitamin supplements might affect sperm parameters and contribute to the chances of a couple to conceive.

The aim of our study was to determine the type and frequency of chromosomal aberrations and polymorphisms in men with different degrees of spermatogenic failure in comparison to men with normozoospermia, in order to find correlations between cytogenetic findings and the abnormal results of semen analysis. In our study, we performed cytogenetic analysis in 901 infertile men, divided into five groups according to semen analysis—normozoospermia (86), asthenozoospermia (394), oligoasthenozoospermia (182), severe male factor (100), and azoospermia (139). The frequency of polymorphisms was similar in all groups (11–16%, without significant differences). The frequency of numerical and structural aberrations increases with the degree of the spermatogenic failure (3.5% in normozoospermia, 5.6% in asthenozoospermia, 9.8% in oligoasthenozoospermia, 9% in severe male factor, and 13.5% in azoospermia). We found a significantly higher incidence of numerical chromosomal aberrations in severe male factor (7%) and azoospermia (9.3%). Oligoasthenozoospermia occured in 45% of cases with translocation, compared to 20% in the group with a normal karyotype. We revealed that chromosomal translocations are tightly associated with oligoasthenozoospermia, whereas numerical chromosomal aberrations—with severe male factor and azoospermia. The impact of chromosome polymorphisms on male infertility should be studied in greater detail.

The aim of this study was to evaluate the association between advanced paternal age (APA) and intrauterine insemination (IUI) outcomes. This retrospective cohort study included 861 IUI cycles in couples in which the female partner was ≤ 35 years. Patients were stratified according to paternal age into a control group (< 40 years) and a study group (≥ 40 years). The study group was further subdivided into two categories of APA: men aged 40–44 years and ≥ 45 years. Primary outcomes were clinical pregnancy rate (CPR), miscarriage rate (MR), and live-birth rate (LBR). No significant differences were observed between the control and the study groups in CPR (17.9% vs. 16.9%), MR (7.5% vs. 15.7%), or LBR (15.2% vs. 12.8%) (all p > 0.05). A subgroup analysis showed no differences between controls and men aged 40–44 years. In contrast, in men aged ≥ 45 years, MR was significantly higher (44.4% vs. 7.5%, p < 0.05) and LBR was significantly lower (6.6% vs. 15.2%, p < 0.05). Paternal age of 45 years or older is associated with increased miscarriage rates and reduced live-birth rates following IUI, whereas no effect was observed for the 40–44 age group.