BACKGROUND The purpose of this study was to compare laboratory and clinical outcomes of intracytoplasmic morphologically selected sperm injection (IMSI) and conventional intracytoplasmic sperm injection (ICSI) in couples with repeated implantation failures. METHODS A total of 200 couples with at least two prior unsuccessful ICSI cycles were enrolled: 100 couples were submitted to IMSI and 100...

Intracytoplasmic sperm injection (ICSI) is the latest of several microfertilization techniques that have been utilized predominantly to overcome severe male subfertility, giving fertilization and term pregnancy rates similar to conventional in-vitro fertilization (IVF) (but for other indications). Even though available data on children born after ICSI are very encouraging, the procedure must st...

Spermatid microinjection into oocytes was applied in cases of intracytoplasmic sperm injection (ICSI)/testicular sperm extraction (TESE) where no spermatozoa could be found in numerous testicular samples. Although several pregnancies were obtained with this procedure, serious concerns remain regarding its safety. Although the relevance of the injection of spermatids is by no means certain, we w...

Recent progress in cell micromanipulation has made it possible to achieve fertilization even with highly deficient male gametes, by injecting them directly to oocyte cytoplasm. This technique, known as intracytoplasmic sperm injection (ICSI), has proved efficient in most types of sperm pathology. However, ICSI fails when injected spermatozoa are not capable of supporting the process of oocyte a...

Assisted reproductive technology with intracytoplasmic sperm injection (ICSI) is becoming an international panacea for couples struggling with infertility. The increasing popularity of these techniques and the data generated has given us a better understanding of the efficacy, consequences and costs of these procedures. There still remain many unanswered questions and controversies surrounding ...

The aim of this comparative clinical study was to examine whether the fertilizing potential of frozen-thawed testicular sperm in the most severe cases of hypospermatogenesis is reduced compared with fresh testicular sperm. The results could determine the necessity of using fresh testicular sperm cells, which mandates involving the spouse by performing simultaneous in vitro fertilization intracy...

To evaluate the potential for fertilization by sperm injection into fish eggs, sperm from zebrafish, Danio rerio, were microinjected directly into egg cytoplasm of two different zebrafish lines. To evaluate physiological changes of gametes on the possible performance of intracytoplasmic sperm injection (ICSI), four different combinations of injection conditions were conducted using activated or...

Azoospermia, cryptozoospermia and necrospermia can markedly decrease the ability of males to achieve pregnancy in fertile females. However, patients with these severe conditions still have the option to be treated by intracytoplasmic sperm injection (ICSI) to become biological fathers. This study analyzed the fertilization ability and the developmental viabilities of the derived embryos after I...

BACKGROUND The use of immature oocytes is limited to cases where these are the only available oocytes, and they are usually only microinjected with sperm after having undergone maturation in vitro. This study compares the outcome of injection of sperm into metaphase I oocytes immediately after their denudation (MI) performed 2 h after their retrieval, with the outcome of injection of sperm into...

OBJECTIVE The decision to use in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), or split insemination (IVF-ICSI) in the first cycle is based on the number of motile sperm. Hence, total fertilization failure (TFF) often occurs during IVF cycles, despite normozoospermia. To investigate whether the cumulative motile swim-up spermatozoa percentage at 22 hours post-insemination ...