Biomedical subjects

Basak Balaban

Publications and source records attributed to Basak Balaban.

21 records · Page 2Linked to original sources

PubMed2002

Transfer at the blastocyst stage of embryos derived from testicular round spermatid injection.

BACKGROUND: Intracytoplasmic injection of testicular round spermatids has been suggested as a salvage treatment in couples when testicular sperm extraction does not yield any mature sperm. However, the success of the procedure is debatable, and controversy surrounds issues such as the presence and (if present) identification of spermatids in testicular tissue. Progression rate to the blastocyst stage of spermatid-derived embryos appears to be low. METHODS: In this study, we investigated the feasibility and outcome of blastocyst stage embryo transfer after round spermatid injection (ROSI). ROSI was undertaken in 58 couples who did not yield mature or elongated sperm to testicular sperm extraction. RESULTS: The incidence of blastocyst formation from two pronuclear oocytes was 7.6%. A total of 16 blastocysts were transferred in 12 patients (20.7%). None of the patients conceived. CONCLUSIONS: The results of this study indicate that the blastocyst stage is reached by only very few ROSI-derived embryos and these embryos do not implant.

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PubMed2002

A comparison of four different techniques of assisted hatching.

BACKGROUND: Assisted hatching (AH) has been proposed as a means to increase the implantation rate in patients with poor prognosis for pregnancy. The procedure appears to be effective when used selectively. Several different methods for AH have been introduced over the years but comparative studies are lacking. The aim of the current study was to compare retrospectively the efficacy of AH performed with four different methods in patients undergoing IVF or ICSI. METHODS: AH was performed prior to day 3 embryo transfer in 794 IVF/ICSI cycles. Indications for AH were females aged >35 years and/or elevated follicular phase FSH levels, previous failed IVF/ICSI cycles, poor embryo quality, and thick zona pellucida (>15 microm). Assignment to one of the four methods of AH was according to the availability of the particular method during the study period. The study was not randomized. RESULTS: Partial zona dissection was used in 239, acid Tyrode in 191, diode laser in 219 and pronase thinning of the zona pellucida in 145. Mean female age, mean number of previous failed IVF/ICSI cycles, number of oocytes retrieved, fertilization and cleavage rates, good quality embryos and zona thickness on day 3 did not differ between groups. Mean number of embryos transferred, implantation rate, clinical pregnancy rate, and abortion rates were likewise similar. CONCLUSIONS: Selective AH using four different methods yields similar implantation and pregnancy rates.

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PubMed2002

Early cleavage of human embryos to the two-cell stage. A simple, effective indicator of implantation and pregnancy in intracytoplasmic sperm injection.

OBJECTIVE: To evaluate the relationship between embryo cleavage time and implantation and pregnancy rates in women undergoing intracytoplasmic sperm injection (ICSI) for male factor infertility. STUDY DESIGN: A total of 78 patients undergoing their first ICSI cycle were evaluated prospectively. Embryos were assessed for early cleavage to the two-cell stage 27 hours after injection. RESULTS: Early cleavage of at least one embryo was observed in 48 cycles (group I). None of the embryos cleaved early in the remaining 30 cycles (group II). There was no difference regarding mean patient age, duration of ovarian stimulation, number of gonadotropin ampules used, number of oocytes retrieved, fertilization, cleavage rates and embryo quality between the two groups. Implantation and clinical pregnancy rates were significantly higher in group I than II (17.9% and 45.8% vs. 5.1% and 16.7%, respectively; P < .05). Furthermore, progression to the blastocyst stage in excess embryos was significantly higher in group I than II (56.7% vs. 25.0%, P < .05). CONCLUSION: Pregnancy and implantation rates were higher in patients who have early cleaving embryos; absence of early cleavage was associated with a poor outcome.

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