Origin of tripronucleate zygotes after intracytoplasmic sperm injection

Cytogenetic analysis of human zygotes displaying three pronuclei and one polar body after intracytoplasmic sperm injection.

BACKGROUND Digynic zygotes with three pronuclei and one polar body obtained after intracytoplasmic sperm injection (ICSI) were studied cytogenetically to elucidate the frequency and origin of chromosomal abnormalities at the earliest stage of conception. METHODS Uncleaved, single-cell zygotes were incubated with podophyllotoxin and vinblastine and fixed by a gradual fixation air drying method...

Ultrastructure of gametes after intracytoplasmic sperm injection.

The ultrastructure of 18 metaphase-II oocytes after intracytoplasmic sperm injection (ICSI) was analysed from 30 min to 8 h following the microinjection. Three control metaphase-II oocytes were not injected. The 21 oocytes were embedded individually and examined in serial pole-to-pole sections. Seventeen oocytes had been matured in vitro from the germinal vesicle stage and showed ultrastructura...

Failed fertilization after clinical intracytoplasmic sperm injection.

Intracytoplasmic sperm injection (ICSI) has resulted in pregnancy and birth for many couples, including those with severe male factor infertility. However, even after ICSI, complete failure of fertilization occurs in 1-3% of cycles. Most cases occur due to low number of mature oocytes, failure of oocyte activation or non-availability of appropriate spermatozoa for injection. Given the significa...

Intracytoplasmic sperm injection (ICSI).

Intracytoplasmic Sperm Injection

Intracytoplasmic Sperm Injection (ICSI) is an assisted reproductive technique [4] (ART) initially developed by Dr. Gianpiero D. Palermo [5] in 1993 to treat male infertility [6]. It is most commonly used in conjunction with in vitro [7] fertilization [8] (IVF) or a less commonly used technique called zygote intrafallopian transfer [9] (ZIFT). In natural fertilization [8], the sperm [10] must pe...