Biomedical subjects

Cristina Lagalla

Publications and source records attributed to Cristina Lagalla.

3 recordsLinked to original sources

PubMed2006

Cumulative pregnancy rates resulting from the use of fresh and frozen oocytes: 7 years' experience.

Storing supernumerary embryos and transferring them later fully utilizes the reproductive potential of retrieved oocytes, allowing a significant increase in the overall number of pregnancies achieved from a single cycle of ovarian stimulation treatment. As an alternative to embryo cryopreservation, preservation of unfertilized oocytes has been proposed to maximize clinical outcome. This paper presents data concerning the cumulative pregnancy rate after use of fresh and cryopreserved oocytes. In 80 treatment cycles in which patients chose to have only a few fresh oocytes inseminated, 24 pregnancies were obtained (30.0%), with an implantation rate of 22.6%. After cryopreservation with the standard slow-cooling protocol, the survival, fertilization and cleavage rates of 918 frozen oocytes were 43.4, 51.5 and 86.0% respectively. A total of 14 frozen pregnancies were achieved, with pregnancy rate 19.2% per transfer and implantation rate 12.3%. The cumulative pregnancy rate was 47.5% per patient. Therefore, despite a low rate of oocyte post-thaw survival, it appears that oocyte storage appreciably improves the number of pregnancies per treatment cycle in cases in which only a minority of oocytes are destined for the fresh treatment. This outcome provides valuable information for appraising the chances of clinical success when the option of embryo cryopreservation is not available.

Adult↗

PubMed2005

Predictive factors for embryo implantation potential.

In spite of recent improvements in IVF, pregnancy rates have not increased significantly and one of the major problems remains the high multiple pregnancy rate. Better criteria are therefore necessary to establish the viability of a transferable embryo. Early prognosis of the developmental fate of the oocyte would help in selecting the best embryos to transfer, but non-invasive selection at the oocyte stage (extracytoplasmic and intracytoplasmic morphology) has proved to be of little prognostic value. Recently, it has been shown that follicular vascularization appears to be predictive of oocyte developmental fate, making it a good first-step approach for selection. Observation of pronuclei patterns at the zygote stage appears to offer an additional prognostic tool, correlating well with IVF outcome. Morphological evaluation of the embryo at days 2-3 remains the most used and valid method of selection, even though it is not sufficient to select embryos with the higher implantation potential. Blastocyst culture is another possible strategy for selecting the best embryos with reduced risk of aneuploidies, though not all major chromosomal aberrations are excluded by prolonged in-vitro culture. In summary, selecting the best embryo for transfer is a decision that should be based on choices made during the different stages of assisted reproductive technologies.

Blastocyst↗

PubMed2004

Artificial reproductive technology achievements for optimizing embryo quality.

Evaluation of morphological characteristics, to date, has been the most widely accepted method for the selection of embryos with higher developmental ability and optimization of the outcome of in vitro fertilization (IVF). Improvement in clinical results has also been pursued through attempts to generate embryos of high quality or to identify more reliable selection criteria. This work evaluates the possibility of improving embryo quality and subsequent IVF outcome in situations in which creation of supernumerary embryos is not allowed. Optimization of gamete selection and conditions of insemination, such as hormonal therapy to improve sperm quality of patients undergoing intracytoplasmic sperm injection treatment, use of power Doppler image for follicle selection, short coincubation of gametes during insemination, and use of a polscope for spindle detection, is described.

Blastocyst↗