Uso de antagonistas de GnRH (Cetrorelix) en reproducción asistida: primer informe en la literatura mexicana / Use of GnRH antagonists (cetrorelix) in assisted reproduction: first report in Mexican literature

The use of GnRH antagonists in assisted reproduction techniques (ARTs) has been shown to be effective in blocking the luteinizing hormone (LH), without a repercussion on ovaric response. The present study reports the use of a GnRH antagonist (cetrorelix) 0.25 mg/d s.c. in patients stimulated with recombinant FSH (rFSH) for IVF/ICSI. 44 patients with mean age of 33.3 years were included in this study, four patients were receptors for oocyte donation program and another patients was receptor for frozen embryos. Controlled ovarian stimulation was carried out with rFSH, starting on day 3 of menstrual cycle. The total mean dose used was 3.570 +/- 1.102 UI for each patient. The LH serum concentrations were monitored during ovaric stimulation, in two patients a premature LH surge (> 10 UI/L) was detected. The oocytes were collected 36 hours after hCG administration, the mean preovulatory oestradiol was 4.006 +/- 2.418 pg/mL. The mean total oocytes retrieved was 10.8 +/- 7.4 per patient, the fertilization rate was 58.3, in only three patients fertilization was failed. No difference was observed in oocyte retrieval, fertilization rate, implantation rate between both groups (GnRH antagonists versus GnRH agonists). The embryo transfer was realized on day 3, and only two patients was on blastocyst stage. In 17 of 41 patients with successful transfer, pregnancy was achieved in the group with antagonists, and 8 of 20 patients in the group with agonists. In conclusion Cetrorelix prevents adequately premature LH surges and allows an effective ovaric response in controlled stimulation in IVF cycles, except in patients in oocyte donation programs who require higher cetrorelix doses.

Falla inesperada en la fertilización in vitro convencional: reinseminación con ICSI o indicación de ICSI en ciclos subsecuentes / Unexpected failed fertilization in vitro: ICSI reinsemination or ICSI indication for subsequent cycles

The objective was to determine if intracytoplasmatic sperm injection (ICSI) for "rescue" of unexpected failed conventional insemination should be carried out for therapeutic or diagnostic purposes, that is, as a predictor for performing ICSI as a standard treatment in subsequent cycles. A retrospective clinical study was carried in 26 patients who showed unexplained fertilization failure on a first conventional IVF attempt, and reinsemination by ICSI was performed. We compared these results with those of 13 of the 26 patients who underwent a second attempt in which ICSI was used as the only insemination technique. A fertilization rate of 46.27 was achieved with reinsemination by ICSI but none resulted in pregnancy (0). Fertilization was achieved with ICSI in all patients with previous fertilization failure and a pregnancy rate of 38.46. Patient characteristics, cycle characteristics, sperm parameters or oocyte quality did not differ significantly between two groups. In conclusion, the ICSI reinsemination technique can give good fertilization rates but the potential of the generated embryos to achieve pregnancy seems to be low. In addition, it can be demonstrated that these patients have good possibilities of obtaining a pregnancy in a following cycle using ICSI.

La cirugÝa pÚlvica como un marcador predictivo de la respuesta folicular a los inductores de ovulación / Pelvic surgery as a predictive marker of the follicular response to ovulation inducers

OBJECTIVE: Comparing the follicular response in a group of patients with previous pelvic surgery submitted to in vitro fertilization. MATERIAL AND METHODS: Patients who were going to be submitted to controlled ovarian stimulation and in vitro fertilization were included. Two groups were formed: one with those patients who had had a previous pelvic operation and the other with those patients who had not. The characteristics which were analyzed included: age, weight, body mass index, FSH, LH and estradiol levels, as well as total ova numbers, grade of embryonic maturity, and number of transferred embryos. RESULTS: Ninety nine patients were studied: 46 had been submitted to pelvic surgery and 53 had not. Due to the design of the study there were no differences regarding age, weight, size and body mass index; the evaluation of the ovarian reserve was similar in both groups. However, the group of patients previously submitted to pelvic surgery presented a lower quantity of total ova (p = 0.004), less mature ova (p = 0.008) with a significantly lower pregnancy rate. CONCLUSIONS: Surgical procedures, combined with adherence processes, probably have a direct incidence on the characteristics of the perifollicular environment which interfere with adequate development of the ovum. All these can be observed in a decrease of fertilization processes and embryonic development, regardless of the expression of the adequate biochemical markers of the ovarian reserve. Our research shows that the group under study presents a decrease in follicular response affecting the quality of the ovum-embryo expressed in the pregnancy rate.

Competitividad óvulo-embrionaria determinada a través de la cuantificación de los Ýndices perifoliculares en la microarquitectura vascular por Doppler / Ovum-embryo competitiveness determined by the quantification of perifollicular indices in Doppler vascular micro-architecture

OBJECTIVE: To obtain the linear correlation between Doppler flowmetry rates and follicular development and the observed embryo growth in ovarian hyperstimulation cycles in the IVFTE/ICSI results. MATERIAL AND METHODS: A prospective and observational study including 29 patients was carried out. The ovarian reserve was determined--by the ovaries morphometric conditions--as well as basal FSH. These were correlated with pulsatility rates (PR), resistance rates (RR), and the systole/diastole ratio (S/D) and the maximum flow rate (TAmax), using a USG pulse-colour Doppler. All these were correlated to embryo development. Covariance, regression lines and confidence intervals analyses were performed for its statistical determination. RESULTS: A correlation between RR and the formation of mature follicles was observed (p = 0.05), and, at the same time, a negative relationship between FSH and ovarian volume was found. CONCLUSIONS: A series of markers of ovarian reserve have been described, however, none of these is a specific marker when ovum quality is expressed through the administration of ovulation inducers. Considering the data obtained in our study, we can say that Doppler flowmetry rates can indicate follicular expression and the resulting ovum and embryo development.