Free Access Articles
Oocyte vitrification in the 21st century and post-warming fertility outcomes: a systematic review and meta-analysis
Oocyte cryopreservation is a rapidly developing technology, which is increasingly being used for various medical, legal and social reasons. There are inconsistencies in information regarding survival rate and fertility outcomes. This systematic review and meta-analysis provides evidence-based information about oocyte survival and fertility outcomes post warming to help women to make informed choices. All randomized and non-randomized, controlled and prospective cohort studies using oocyte vitrification were included.Sperm DNA damage caused by oxidative stress: modifiable clinical, lifestyle and nutritional factors in male infertility
DNA fragmentation is an important factor in the aetiology of male infertility. However, it is still underevaluated and its inclusion in routine semen analysis is debated. DNA fragmentation has been shown to be a robust indicator of fertility potential, more so than conventional semen parameters. Men with high DNA fragmentation levels have significantly lower odds of conceiving, naturally or through procedures such as intrauterine insemination and IVF. Couples may be counselled to proceed directly to intracytoplasmic sperm injection as it is more successful in this group, avoiding costly procedures, recurrent failures or pregnancy losses; however, this treatment is not without limitations or risks.Polarization microscopy and rescue ICSI
A fraction of standard IVF cycles is afflicted by total fertilization failure. For several years, attempts have been made to develop strategies for rescuing these cycles in order to reduce the physical, psychological and economic burden imposed by an assisted reproduction technology treatment. Rescue ICSI is the approach by which failed fertilized oocytes can be microinjected on day 1 post insemination with the aim of achieving fertilization and thereby preventing cycle cancellation. In a study presented in this issue, Moon and colleagues perfected the rescue ICSI methodology by adopting polarized light microscopy as a tool to identify and treat only failed fertilized oocytes not penetrated by spermatozoa.IVF versus ICSI for the fertilization of in-vitro matured human oocytes
Traditional dogma suggests that intracytoplasmic sperm injection (ICSI) should be performed to ensure successful oocyte fertilization in an in-vitro maturation (IVM) cycle. This study postulated that there would be no difference in the fertilization rate when ICSI was compared with IVF. This hypothesis was tested in a randomized trial of IVF versus ICSI in IVM. A total of 150 immature oocytes were collected in eight cycles of IVM for patients diagnosed with polycystic ovarian syndrome (PCOS). Patients were primed with minimal FSH before transvaginal oocyte aspiration.Clinical outcome of intracytoplasmic injection of spermatozoa morphologically selected under high magnification: a prospective randomized study
Recent evidence shows that the selection of spermatozoa based on the analysis of morphology under high magnification (×6000) may have a positive impact on embryo development in cases with severe male factor infertility and/or previous implantation failures. The objective of this prospective randomized study was to compare the clinical outcome of 87 intracytoplasmic morphologically selected sperm injection (IMSI) cycles with 81 conventional intracytoplasmic sperm injection (ICSI) cycles in an unselected infertile population.
