In vitro fertilization technology consists of the selection and fertilization of oocytes, the production and transplantation of embryos to recipients. The quality of oocytes has a direct impact on the fertilization and developmental competence of oocytes. Criteria that show the quality of oocytes are subdivided into morphological, cellular, and molecular. The aim of this article was to review the morphological criteria that are used for estimation of the quality of oocytes before their fertilization in vitro. These criteria include the evaluation of the structure of oocyte: cumulus complex, oocyte cytoplasm, polar body, perivitelline space, zona pellucida, and meiotic spindle.

The quality of sperm has a direct influence on the fertilization and developmental competence of embryos. In the literature we did not find defined criteria for evaluation of normal sperm parameters in various species of domestic mammals. Therefore we attempted to review evaluation of criteria of morphologically normal human sperm and their abnormalities. All sperm cells observed in the stained sample are classified as normal or abnormal. Any abnormalities in morphology of sperm have a negative effect on the outcome in in vitro fertilization and intracytoplasmic sperm injection. Abnormal sperm are categorized into subgroups according to the observed defects (concerning the head and/or midpiece and/or tail). Most morphologically abnormal sperm have multiple defects. This article can be considered as guideline for the manual of sperm quality evaluation in different species of domestic mammals.

In the literature, there are no data on the effects of copper (Cu) on the development and birth defects of live-bearers freshwater fish embryos. The aim of this study was to investigate the influence of copper sulphate (CuSO 4) pentahydrate on the development of embryos in the guppies (Poecilia reticulata). Guppies were exposed to concentration of 0.5, 1.0 and 1.5 mg/L of CuSO 4 pentahydrate for 24 h. After 15 days, the female fish was euthanised and the embryos were dissected. No visible lesions were observed in the embryos of guppies exposed to 0.5 mg/L of CuSO 4 pentahydrate. In the guppies exposed to 1.0 mg/L CuSO 4 pentahydrate, the embryos showed visible abnormalities from blastodisc to middle-eyed stages of development. In the late (very late-eyed and mature embryo) stages embryos, the morphological abnormalities were not observed. The exposure to 1.5 mg/L of CuSO 4 pentahydrate caused the death of guppies and their embryos during 24 h. In the light of these results, the 1.0 mg/L and higher dose of CuSO 4 pentahydrate is not recommended for the treatment of guppies because this decreases the viability of guppies and causes morphological abnormalities and mortality in their embryos.

Oocytes collected from patients following ovarian stimulation exhibit varying qualities. The quality of oocytes has an effect on its subsequent fertilization, developmental competence postfertilization and the viability of resultant embryos. The aim of this article was to review the morphological criteria devised for assessment of oocyte quality by ordinary light and polarized light microscopy before IVF or ICSI. The parameters employed in the evaluation of oocyte morphology include the appearance of: structure of the cumulus-oocyte complex, oocyte cytoplasm, perivitelline space, zona pellucida, polar body and meiotic spindle.The authors have nothing to declare.

This study aimed the comparison of the isolated testes size, volume, weight and density changes with age and establishing the suitability of three formulas of testicular volume calculation for 18-50 and 51-70-year-old men groups. 206 testes of 103 men (59 of 18-50-year-old and 44 of 51-70-year-old men) were weighed and their size was measured by the sliding calliper. The accurate volume was determined by water displacement and compared with volume calculated using three formulas, and the density of testicular tissues was calculated.The mean length and height of both testes and length and height of right and left testes decreased significantly with age. The mean width of both testes and width of right and left testes decreased with age insignificantly. The mean of water displacement volume and weight and volume and weight of right and left testes decreased with age significantly. The mean density of testicular tissues and the density of the right and left testes increased significantly with age. In the same age group, the size, water displacement volume and weight of right testes was insignificantly major than the left, and the density of testicular tissues was similar in the right and left testes.The prolate spheroid formula was most suitable for calculation of testes volume for 18-50-yearold men and prolate ellipsoid formula was most suitable for calculation of 51-70-year-old men testes volume.