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I Craft

Publications and source records attributed to I Craft.

At least 19 recordsLinked to original sources
PubMed2004

Detailed FISH analysis of day 5 human embryos reveals the mechanisms leading to mosaic aneuploidy.

BACKGROUND: Fluorescence in situ hybridization (FISH) analysis has shown that human embryos display a high level of chromosomal mosaicism at all preimplantation stages. The aim of this study was to investigate the mechanisms involved by the use of two probes for each of three autosomes at different loci and to determine the true level of aneuploid mosaicism by excluding FISH artefacts. METHODS: Embryos were cultured in two different types of medium: group I were cultured in standard cleavage medium for up to day 5 and group II were cultured from day 3 to day 5 in blastocyst medium. Three rounds of FISH were performed. In round 1, the probes used were 1pTel, 11qTel and 18CEP; in round 2, the probes used were 1satII/III, 11CEP and 18qTel; in round 3, the probes used were 18CEP, XCEP and YCEP. RESULTS: A total of 21 embryos were analysed in each group. The FISH results revealed one uniformly diploid and 20 mosaic embryos for group I, and two uniformly diploid and 19 mosaic embryos for group II. The predominant type of mosaicism was diploid/aneuploid. The use of two different probes per autosome was able to distinguish FISH artefacts affecting 5% of nuclei from true single cell anomalies. CONCLUSIONS: Post-zygotic chromosome loss was the most common mechanism leading to aneuploidy mosaicism for both groups, followed by chromosome gain, with fewer examples of mitotic non-disjunction.

Adult↗
PubMed1999

Comparison of pregnancy outcome of pronuclear- and multicellular-stage frozen-thawed embryo transfers.

PURPOSE: Our purpose was to determine if supernumerary embryos generated by in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) should be frozen (using 1,2-propanediol) at the pronuclear or multicellular stage. METHODS: The study was a retrospective analysis conducted at the Dubai Gynaecology & Fertility Centre of the Department of Health & Medical Services, Dubai, U.A.E. One hundred forty-one women undergoing frozen-thawed embryo replacement cycles with IVF generated embryos and 84 women undergoing the same with ICSI generated embryos. RESULTS: Supernumerary, IVF-generated embryos frozen at the multicellular stage had a significantly higher rate of survival on thawing (73.9%) than embryos frozen at the pronuclear stage (64.4%). The morphological grades of the embryos in the two groups were similar, but a significantly higher pregnancy rate was obtained with embryos frozen at the multicellular stage (22.8%) than with pronuclear-stage embryos (14.8%). Similarly, with ICSI-generated embryos, significantly higher survival was seen with multicellular-stage frozen embryos (74.8%) than pronuclear-stage embryos (64.4%). The morphological grades of the embryos and pregnancy outcomes of the two groups were similar. CONCLUSIONS: Supernumerary embryos generated by IVF and ICSI should be frozen at the multicellular stage so as to allow selection of the best embryos for transfer and embryo freezing of only robust embryos.

Blastocyst↗
PubMed1999

Will GnRH antagonists provide new hope for patients considered 'difficult responders' to GnRH agonist protocols?

We have assessed the use of cetrorelix, a gonadotrophin releasing hormone (GnRH) antagonist, in conjunction with clomiphene citrate and gonadotrophin in 31 in-vitro fertilization (IVF)/gamete intra-Fallopian transfer (GIFT) cycles for 25 difficult responders. Group I included 18 poor responders (24 cycles) with no live birth in 23 previous IVF cycles with GnRH agonists. Group II included seven patients (seven cycles) with polycystic ovaries. Thirteen previous IVF/GIFT cycles with GnRH agonists had resulted in one live birth and three of these patients had developed ovarian hyperstimulation syndrome (OHSS). The treatment protocol involved a daily dose of clomiphene citrate 100 mg for 5 days and gonadotrophin injections from cycle day 2. Cetrorelix 0.25 mg/day was started when the leading follicle reached 14 mm. The outcome in both groups was favourable compared to previous treatment with GnRH agonists. In group I the abandoned cycle rate was 29 versus 57% (P = 0.06). More oocytes were produced (6.4 versus 4.7 oocytes/cycle) at a lower dose of follicle-stimulating hormone (FSH) (709 versus 1163 IU/oocyte; P = 0.08) and two live births resulted (11.8%). In group II fewer oocytes were produced (10.2 versus 14.5 oocytes/cycle), using a lower dose of gonadotrophin (170 versus 189 IU/oocyte) and resulted in one ongoing pregnancy. No patients experienced OHSS. This report is preliminary and a further controlled randomized study is required.

Clomiphene↗
PubMed1997

Testicular needle aspiration as an alternative to biopsy for the assessment of spermatogenesis.

The technique of fine needle aspiration (FNA) may have a role as a reliable, quick and easy method of obtaining testicular tissue. Recent advances in the management of male subfertility and, in particular, the finding that spermatozoa recovered from the epididymis and testis can result in embryo generation after intracytoplasmic sperm injection (ICSI), question the traditional role of open testicular biopsy for the assessment of spermatogenesis. FNA of the testis was performed on 19 cases of male subfertility and histological and cytological preparations obtained were assessed by light microscopy. FNA provided intact testicular tubules adequate for the histological assessment of spermatogenesis in all cases. There was good correlation with the cytological preparations which gave an indication of the number of mature spermatozoa present. FNA should be considered as a simple alternative to open testicular biopsy in the current investigation of male subfertility and as a method of retrieving spermatozoa for assisted conception using ICSI.

Adult↗
PubMed1996

High levels of spermine in IVF medium as a negative predictor of subsequent success of embryo transfer.

PURPOSE: Our purpose was to test the prediction that spermine levels in IVF culture supernatants measure by rapid ELISA assay correlate with subsequent success or failure to establish a pregnancy. RESULTS: Forty-nine patients undergoing gonadotropin-stimulated ovulation after LHRH analogue treatment in the current study succeeded and 57 failed. With the exception of the first 4 hr of culture, where polyamine levels were slightly (but not significantly) higher in supernatants associated with subsequent success, higher levels of polyamines were predictive of failure. CONCLUSIONS: The result in this study differs from previous data obtained with women ovulated using clomiphene where low spermine levels (assayed in an immunosuppression assay in vitro) correlated with failure to establish pregnancy, and detectable levels correlated with success. Supplementation of IVF culture medium with spermine and/or spermidine appears unlikely to improve IVF success rates, where the success rate is already very good, and may possibly do harm. The possibility that different methods of ovulation affect subsequent polyamine production in vitro by fertilized oocytes merits further study.

Culture Media, Conditioned↗
PubMed1996

What factors predetermine the risk of having a high-order multiple pregnancy with gamete intra-fallopian transfer?

Limiting the number of oocytes transferred at gamete intra-Fallopian transfer (GIFT) has limited the incidence of high-order pregnancy but at the same time compromised the fertility potential of some patients. A review of 300 patients who have undergone GIFT using a flexible approach as to the number of oocytes transferred identifies the patients at risk of high-order pregnancy as those aged under 30 years in whom more than six oocytes are returned and whose partner's spermatozoa have high progressive motility.

Adult↗