[Effect of sexual abstinence on pregnancy rates after an intrauterine insemination]. / Efecto de la abstinencia sexual en las tasas de embarazo posterior a inseminación intrauterine.

BACKGROUND: There are many studies showing that more days of sexual abstinence increased sperm concentration, however, the direct influence between the days of abstinence and pregnancy rates has not been evaluated. The usual recommendation is 3-4 days prior to intrauterine insemination; this based on the interval that maximizes the number of motile sperm in the ejaculate. There are some reports with better success rate when abstinence is less than three days. OBJECTIVE: To evaluate the pregnancy rate post-intrauterine insemination according to days of sexual abstinence prior to obtaining semen sample. PATIENTS AND METHODS: A retrospective, observational and transversal study in patients attending the Mexican Center for Fertility (CEPAM) to intrauterine insemination. For analysis patients were grouped by age group, success rate and days of sexual abstinence. Continuous variables are reported as means and standard deviations; to determine statistical significance univariate logistic regression was performed. Categorical variables were evaluated in frequencies and percentages. The calculations were performed using JMP software program. RESULTS: 3,123 couples were included and increased success rate for intrauterine insemination was obtained with less than seven days of sexual abstinence. The rate of sperm retrieval is inversely proportional to the days of abstinence. CONCLUSION: A better pregnancy rate in intrauterine insemination was achieved with less than seven days of sexual abstinence and sperm retrieval rate was also recorded with fewer days of abstinence.

[Assessment of progesterone levels on the day of the hCG administration as a predictor of success of antagonist stimulation protocols for IVF]. / Evaluación de la concentración de progesterona el día de la administración de hCG como predictor de éxito en protocolos de estimulación con antagonista para fertilización in vitro.

BACKGROUND: There are reports of deleterious effect when progesterone concentration is high during the follicular phase in cycles of in vitro fertilization. In our environment has not carried out a study to evaluate the pregnancy rate compared with progesterone concentration on the day of application of hCG. OBJECTIVE: To evaluate the pregnancy rate and outcome of in vitro fertilization cycle according to serum progesterone concentration on the day of application of hCG. MATERIAL AND METHODS: A retrospective, observational, cross-sectional study of 486 cycles of in vitro fertilization was done in the Centro Mexicano de Fertilidad of CEPAM (Hospital Angeles de las Lomas) from January 2009 to February 2014. We included all cases where it was used a stimulation protocol GnRH antagonist flexible scheme. RESULTS: When levels of progesterone are high, those of estradiol are also high and the number of retrieved oocytes and oocyte quality are lower. There was no difference in the percentage of fertilization, but at higher concentration of progesterone lower percentage of embryonic segmentation. Difference was recorded in the pregnancy rate only when progesterone concentration on the day of hCG application was > 4 ng/mL. CONCLUSION: Pregnancy rate decreases when the concentration of progesterone on the day of hCG application is ≥ 4 ng/mL.

[Unselective single embryo transfer: chances of pregnancy related to operator experience]. / Transferencia no selectiva de embrón único: posibilidades de embarazo relacionadas con la experiencia del operador.

BACKGROUND: Selection of best quality embryo aims to achieve higher success rate, the pregnancy is unique and therefore obstetric risks are reduced. OBJECTIVE: To evaluate the pregnancy rate with no transfer of selected single embryo (TSSE) three days versus the experience of the physician performing the embryo transfer. PATIENTS AND METHODS: A retrospective, cross-sectional observational study in 159 patients Mexican Fertility Center in CEPAM protocol in vitro fertilization any indication, other ovulatory disorders and who was only possible obtain an embryo to be transferred in three day. For the analysis were grouped according to age, number of cells of the embryo transfer day and the doctor performed. Continuous variables are reported as means and standard deviations and univariate logistic regression was performed to determine statistical significance. Categorical variables were evaluated in frequencies and percentages. The calculations were performed with the software JMP. RESULTS: Protocol of single-embryo transfer not selected in three day pregnancy rate of 17% was obtained, with lower rates in women over 40 years of age and older embryos of more than 9 cells but also higher rate abortion. More experienced doctors achieved better pregnancy rates. CONCLUSION: This is the first study in Mexican population to assess the possibility of pregnancy with single embryo transfer in selected post-harvest with a three day success rate of 17% and first-order variables: number of cells on the day of transfer and experience of the physician who performed the procedure.

[Assisted hatching following embryo implantation failure]. / Eclosión asistida en pacientes con falla previa en la implantación embrionaria.

BACKGROUND: Assisted hatching in reproduction techniques has improved the successful implantation rates in certain groups of patients with poor prognosis. This study focuses on its effect in groups of patients with previous implantation failure and according to age groups. OBJECTIVE: Compare the pregnancy rates of patients who turned to this technique following an implantation failure using in vitro fertilization with those of patients who did not use assisted hatching before another attempt of in vitro fertilization and according to specific age groups. MATERIAL AND METHOD: Cases of patients using assisted hatching in our Center between January 2008 and December 2009 were studied. The results were compared in terms of age in three groups: group I, >35 years; group II, 35-39 years, and group III, > 40 years. RESULTS: Patients in group II had better pregnancy rate (30%) than those in groups I and III (16.98 and 20.83%, respectively). When comparing the results of the group of patients using assisted hatching with those of the group that did not, the first reported a 20% pregnancy rate versus no pregnancy in the other group.

[Evaluation of two transfer embryo systems performed by six physicians]. / Evaluación de dos sistemas de transferencia de embriones.

BACKGROUND: Embryo transfer is a critical point for success in IVF cycles. Many factors should be considered when performing an embryo transfer such as: embryo quality and number, soft versus rigid catheter, easy of the transfer, physician technique, ultrasound guide during transfer, among others. OBJECTIVE: Evaluate two different embryo transfer systems performed by six physicians with the same protocol. MATERIAL AND METHODS: We evaluated 308 embryo transfers performed from January 2006 to December 2008 by six physicians with two different systems. We only included patients with good quality in embryos and endometrium. Both systems were analyzed in each of the six physicians. RESULTS: Similar characteristics in number of transferred embryos, number of cells in each embryo and quality of them, were found in both groups. There were no significant differences between both systems in the characteristics of the couple nor the mentioned above. Most of the transfers n = 252 (81.81%), were realized by two of the six physicians, however, the pregnancy rate did not show significant differences between these physicians and the less experienced ones. CONCLUSIONS: With the obtained results, it could be supposed that the most influential factor in the outcome is the operator experience in the use of each system and not the system itself.

[Serum estradiol the day of hCG administration as predictor factor of IVF-ET]. / Estradiol sérico el dia de la administración de hCG como factor pronóstico de fertilización in vitro con transferencia de embriones.

BACKGROUND: Since the beginning of assisted reproductive technologies, they have been in search of a pregnancy predictor, mainly in in vitro fertilization, due to its difficulty and expensiveness. OBJECTIVE: To know if there is an optimal estradiol levels to reach pregnancy in patients with in vitro fertilization and embryo transference. MATERIAL AND METHODS: Retrospective and descriptive study of 179 patients in the fresh in vitro fertilization cycles from January 1 to December 31,2006. Patients were grouped by serum estradiol level the day before of hCG administration: Group 1, < 1,000; Group 2, 1,001-1,500; Group 3, 1,501-2,000; Group 4, 2,001-2,500; Group 5, 2,501-3,000, and Group 6, > 3,000 pg/dL. Pearson's chi-square and ANOVA, with Stata, were used to determine whether E2 levels were associated with oocyte number, quality, maturation and pregnancy rates. RESULTS: A significant difference was noted in the number of MII oocytes retrieved and pregnancy rates, but there is no relation with E2 levels. Higher pregnancy rate was at Group 1, where older patients were too. CONCLUSIONS: Estradiol level before hCG administration is not a predictor factor of pregnancy rates, nor even determinant of oocyte retrieval cancellation in patients with in vitro fertilization and embryo transference, mostly in advanced age patients.

[Comparative analysis of pregnancy rate/captured oocytes in an in vitro fertilization program]. / Análisis comparativo de la tasa de embarazo-ovocitos capturados en un programa de fertilización in vitro.

BACKGROUND: Since in vitro fertilization/embryo transfer is used as a common assisted reproductive technique there have been attempts to increase its success rate. One way is to obtain more good quality mature ovules to fertilize them, and two to three good quality embryos to transfer. OBJECTIVE: To determine if the number of retrieved oocytes is related with the pregnancy rate in IVF-ET. PATIENTS AND METHODS: Reproductive and descriptive study; 172 patients in the IVF program were included. Whole patients had ovary stimulation with FSHr and antagonist multidose protocol. Five study groups were considered depending on the oocyte number retrieved. Data were analized and correlated with fertilization and pregnancy rate. RESULTS: There were no statistical differences among age, body mass index, percentage of mature oocyte, fertilization rate, embryo cell stage or basal levels of LH and Estradiol. Group three showed the highest pregnancy rate (64.29%) nevertheless group five had major number of embryo transferred (2.97 +/- 0.54 vs 3.17 +/- 0.45, p = 0.21). According to FSH doses given, group one had statistical difference related to group three, with higher dose (54.1 vs 62.1). According to previous studies, related to the number of oocyte retrieved, the possibility of pregnancy is higher with more than 13 oocytes retrieved (OR: 0.9 IC 95%: 0.4 -1.7). CONCLUSIONS: Pregnancy rate is higher when ten to fifteen oocytes were retrieved.

Physiological ICSI (PICSI) vs. Conventional ICSI in Couples with Male Factor: A Systematic Review.

OBJECTIVES: To determine the efficacy of the physiological ICSI technique (PICSI) vs. conventional ICSI in the prognosis of couples, with respect to the following outcome measures: live births, clinical pregnancy, implantation, embryo quality, fertilization and miscarriage rates. METHODS: A systematic review of the literature, extracting raw data and performing data analysis. Patient(s): Couples with the male factor, who were subjected to in-vitro fertilization. Main Outcome Measures: rates of live births, clinical pregnancy, implantation, embryo quality, fertilization and miscarriage. RESULTS: In the systematic search, we found 2,918 studies and an additional study from other sources; only two studies fulfilled the inclusion criteria for this systematic review. The rates of live births, clinical pregnancy, implantation, embryo quality, fertilization and miscarriage were similar for both groups. CONCLUSION: There is no statistically significant difference between PICSI vs. ICSI, for any of the outcomes analyzed in this study. Enough information is still not available to prove the efficacy of the PICSI technique over ICSI in couples with male factor.

[Clinical implication and frequency of the incidental finding of endometriosis during oocyte retrieval]. / Implicación clinica y frecuencia del hallazgo incidental de endometriosis durante la captura ovular.

BACKGROUND: Endometriosis is a clinical disease that is associated with poor outcomes in in vitro fertilization (IVF) programs with a decrease in oocyte retrieval, oocyte quality, implantation and pregnancy rates. When an endometrioma is diagnosed, it is indicated to remove endometrial cysts by laparoscopy or perform an aspiration before the cycle of IVF. OBJECTIVES: To evaluate the effect of endometriosis diagnosed incidentally during oocyte retrieval on the IVF outcome, as well as to establish its frequency. MATERIAL AND METHODS: Retrospective analysis of 1,000 files of patients who underwent to oocyte retrieval between January 2002 and March 2005, in the Centro Especializado para la Atenci6n de la Mujer in Mexico City. Of the total procedures tubal factor was the first indication for IVF and male factor was on second place. Only in seven patients of 1,000 oocyte retrievals was detected the presence of endometriosis fluid instead of folicular fluid. RESULTS: The prevalence of endometriosis diagnosed incidentally during oocyte retrieval was 0.7%, and the oocyte quality was 1.55 (regular). The fertilization rate for patients with endometriomas was 45% and the implantation and pregnancy rates were zero per cent while the patients without endometriomas the fertilization rate was 65% with an implantation rate of 18% and the pregnancy rate was 35%. CONCLUSION: Endometriosis is a disease that must be treated before an IVF cycle in stages III-IV and especially in presence of endometriomas because it could affect negatively IVF outcomes.

[Statistical and prognostic correlation of serum levels of basal inhibin to response and follicular quality in assisted reproduction]. / Correlación estadística y pronóstica de la concentración sérica de inhibina basal con la respuesta y calidad folicular en reproducción asistida.

BACKGROUND: Inhibin B is a direct marker of ovarian reserve and one of the earliest markers of ovarian aging. It has been used in assisted reproduction programs as a serum marker that can identify an altered follicular reserve and predict a good or poor response to the stimulation with exogenous gonadotropins. OBJECTIVE: To correlate inhibin B levels with follicular response and quality of oocytes obtained through ovarian stimulation controlled in an in vitro fertilization cycle (IVFET), as well as relate it with variables such as: fertilization percentage and pregnancy rates. PATIENTS AND METHODS: In a prospective and transversal study we included 71 patients that entered the IVFET program (February-April 2005). We determined inhibin B levels at the third day of the cycle and evaluated the follicular response and the oocyte quality during the ovarian stimulation, as well as fertilization and pregnancy rates. Statistical analysis was made with Spearman's and ANOVA tests. RESULTS: We observed a positive correlation between inhibin levels and quantity of developed follicles (0.457), number of captured oocytes (0.390), and quantity of metaphase II oocytes (0.324). We observed better oocyte quality in women with inhibin levels > 251 pg/ mL, and we considered that the ones that had levels < 50 pg/mL had poor follicular response (19.71%). There was no correlation with fertilization and pregnancy rates. CONCLUSIONS: In the early follicular phase inhibin B has direct correlation with ovarian reserve. Its high levels are related to better follicular response and oocyte quality. This enzyme levels are not useful as a predictive factor of pregnancy in IVFET cycles.

[Success' determinant variables in assisted reproduction]. / Variables determinantes del exito en la reproducción asistida.

OBJECTIVE: To perform a statistical analysis with variables that have influence on pregnancy rates to establish a prognostic factor of each one. PATIENTS AND METHODS: We performed a retrospective, descriptive, and observational study with 240 patients that underwent to IVF-ET program. The analyzed variables were: infertility factor, ovarian stimulation protocol, age of patients, basal hormonal levels, oestradiol preovulatory levels, endometrial characteristics, fertilization rate, number and quality of oocytes, number and quality of embryos, and difficulty of the embryo transfer. RESULTS: The mean age of the patients was 34 +/- 4.42 years old. Tubal and pelvic pathologies were the main infertility cause. During the statistical analysis we observed that the only variables with differences regarding pregnancy were the number of cells in the embryo (7.18 vs 5.9), the fertilization rate (58.3 vs 50.1%), and the number of transferred embryos. With the logistic regression analysis we observed that the number of cells on each embryo had a relative risk of 1.37 (CI 95%; 1.15-1.63), and that the number of transferred embryos had one of 1.63 (CI 95%; 1.10-1.58). CONCLUSIONS: There are many variables that influence the pregnancy rates, but with our results we consider that the embryo quality, its characteristics and the number of transferred embryos could predict better the possibilities of pregnancy in IVF-ET programs.

[Intrafollicular levels of sexual steroids and their relation with the antioxidant enzymes on the oocyte quality in an in vitro fertilization program]. / Las concentraciones intrafoliculares de esteroides sexuales y su correlación con las enzimas antioxidantes en la calidad de los ovocitos en un programa de fertilización in vitro.

OBJECTIVE: To establish a correlation between intrafollicular superoxide dismutase enzyme concentrations, activity with oestradiol levels, and the effects on oocyte quality and maturity. STUDY: Prospective, descriptive and observational. MATERIAL AND METHODS: Forty-one patients underwent IVF-ET program. The ovarian stimulation protocol was made with recombinant FSH and GnRH antagonists. All follicles were aspirated one by one, and the follicular fluid was stored at a -20 degrees C room temperature. We retrieved 120 follicular fluids and performed the measurement of oestradiol and superoxide dismutase enzyme on each follicular fluid and its correlation with fertilization and cleavage rates. Statistical analysis was carried out with ANOVA, t Student, chi2 and P Pearson tests. RESULTS: Patients' mean age was of 33.74 +/- 5.04 years, the mean of enzyme activity was of 76.89%, and the mean concentration of superoxide dismutase enzyme was of 68.71 UI/L. According to oocyte quality or maturity, no statistical differences were observed when comparing oestradiol levels with superoxide dismutase enzyme concentrations. But when we analized both variables, we observed a positive correlation in metaphase 2 oocytes (p = 0.236). When we correlated the superoxide dismutase enzyme activity with oestradiol concentrations in relation to oocyte quality, a positive correlation in good quality oocytes was observed too (p = 0.218). We perceived a strong correlation between SOD concentrations and oestradiol intrafollicular measurements in good quality oocytes. COMMENTS: Oocyte maturity and development are conditionated by a close relationship between SOD and intrafollicular oestradiol.

[Usefulness of luteinizant hormone levels to determine the oocyte quality]. / Utilidad de las concentraciones de la hormona luteinizante para determinar la calidad ovocitaria.

OBJECTIVE: To evaluate the luteinizing hormone serum preovulatory levels and correlate them with the embryo number and quality, and with the fertilization and clavage rates. STUDY: Prospective, descriptive and observational. MATERIAL AND METHODS: We included 286 patients that underwent to IVF-ET program, we excluded patients with no mesurement of LH preovulatory levels, or patients that in the oocyte retrieval we do not found oocytes. The protocols for pituitary inhibition were: stop Lupron, long luteal phase and GnRH antagonist, the ovarian stimulation was realized with recombinant FSH. The studied variables were: LH preovulatory levels, number and quality of oocytes, fertilization and clevage rates and embryo quality. Statistical analysis was done with p Pearson and ANOVA tests. RESULTS: The mean age for patients was 34 +/- 3.96 years, the principal factor of infertility was tubal and pelvis pathology. The mean LH preovulatory levels were 2.19 +/- 1.83 UI/L by patient, we observed a negative correlation between LH levels and number of oocytes retrieved (p = -0.157, IC 99%), and the correlation between LH levels and number of metaphase 2 oocyte was negative too (p = 0.113, IC 95%). We observed greater levels of LH (3.15 UI/L) in the degenerated oocytes during oocyte retrieval. We did not found a statistical correlation between fertilization and cleavage rates with LH levels. LH preovulatory levels of 0.85 UI/L could predict good quality oocytes with a sensitivity of 72% and specificity of 25%. CONCLUSIONS: Normogonadotrophic patients without deep suppression of gonadotrophins by the use of GnRH analogues, high LH preovulatory levels correlates with a less number of oocytes, and with degenerated oocytes. Preovulatory LH levels of 0.85 UI/L could predict good quality oocytes.

Técnica de doble disparo (doubble trigger) en pacientes normorrespondedoras con bajo porcentaje de ovocitos maduros / Doubble Trigger in patients with a normal response with a low percentage of mature oocytes

Resumen OBJETIVO: Evaluar el efecto del doble disparo en pacientes con un ciclo previo con menos de 65% de ovocitos maduros respecto de los ovocitos capturados, en una población con respuesta normal a la inducción de la ovulación con hCG recombinante o urinaria. MATERIALES Y MÉTODOS: Estudio de cohorte, prospectivo, efectuado en pacientes con diagnóstico de infertilidad, en tratamiento con fertilización in vitro, evaluadas en el Centro Mexicano de Fertilidad (Hospital Ángeles Lomas) entre 2017 y 2019. El tratamiento se llevó a cabo en la misma paciente, en cuyo ciclo previo convencional con esquema de antagonista e inducción de la ovulación con hCG tuvo respuesta ovárica subóptima y captura ovocitaria con menos de 65% en fase M2 (Grupo 1). Posteriormente se les indicó un segundo ciclo con el mismo esquema de gonadotropinas e inducción de la ovulación con doble disparo: acetato de triptorelina 1 mg + 5000 UI de hCG urinaria 40 y 34 horas previas a la captura (Grupo 2). Se evaluaron el porcentaje y la cantidad de ovocitos capturados en fase M2. RESULTADOS: Se registraron 34 pacientes en quienes se llevaron a cabo 68 ciclos. La cantidad de ovocitos capturados fue mayor en el grupo 2 (agonista de GnRH + hCG urinaria; p = 0.03). El doble disparo aumentó el porcentaje de ovocitos maduros (65.4 ± 21.3 vs 74.6 ± 20.2; p = 0.07). CONCLUSIONES: La técnica de doble disparo es valiosa para el tratamiento de pacientes con captura de ovocitos deficiente, aun con desarrollo folicular normal y concentraciones de estradiol adecuadas y óptimas de hCG el día de la captura. Se requieren estudios prospectivos de gran tamaño para dilucidar la recomendación mencionada de la técnica de "doble disparo".

Abstract OBJECTIVE: To evaluate the effect of double trigger in patients with a previous cycle with less than 65% of mature oocytes compared to the captured oocytes, in a normorresponding population with induction of ovulation with recombinant or urinary hCG. MATERIALS AND METHODS: A prospective cohort study, conducted in patients diagnosed with infertility, treated with in vitro fertilization, evaluated at the Mexican Fertility Center (Hospital Angeles Lomas) between 2017 and 2019. The treatment was carried out in the same patient, in whose previous conventional cycle with antagonist scheme and induction of ovulation with hCG had suboptimal ovarian response and oocyte capture with less than 65% in M2 phase (Group 1). Subsequently, a second cycle was performed with the same scheme of gonadotropins and induction of ovulation with double shot: 1 mg triptorelin acetate + 5000 IU of urinary hCG 40 and 34 hours prior to capture (Group 2 or double trigger). Percentage and quantity of oocytes captured in M2 phase were evaluated. RESULTS: 34 patients were registered, in whom 68 cycles were performed. The number of oocytes captured was greater in group 2 (agonist of GnRH + urinary hCG; p = 0.03). The double shot increased the percentage of mature oocytes 65.4 ± 21.3 vs 74.6 ± 20.2 (p = 0.07). CONCLUSIONS: The double trigger technique is valuable for the treatment of patients with poor oocyte capture, even with normal follicular development and adequate and optimal hCG estradiol concentrations on the day of capture. Large prospective studies are required to elucidate the aforementioned recommendation of the "double shot" technique.

[Changes in mitochondrial membrane potentials and its exponential relation with phosphatidylserine translocation in the plasma membrane as markers in the initial events of apoptosis: evaluation in different spermatic fractions]. / Alteración en los potenciales de membrana mitocondrial y su relación exponencial con la translocación de fosfatidilserina en la membrana plasmática como marcadores en los eventos iniciales de apoptosis: evaluación en diferentes fracciones espermáticas.

OBJECTIVE: To determine the integrity of the plasmatic membrane through phosphatidylserine (PS) translocation in two spermatic fractions and their correlation with the spermatic mitochondrial membrane potential. MATERIAL AND METHODS: The analysis of both spermatic fractions was carried out through a discontinuous gradient separation with Percoli, in order to obtain two samples with high and low mobility (90-40%). Twelve patients were recruited for the initial evaluation of seminal parameters. Mitochondrial membrane integrity was determined using a second antibody (Mitosensor), and was analyzed by fluorescence microscopy, evaluating an average of 200 cells. A 450-490 nm excitation filter was used for this analysis. Cytoplasmatic assessment was carried out by anexine V bonding to PS, in order to determine the initial events of cellular death. Non parameter tests were used in order to determine the differences between mitochondrial potentials and plasmatic membrane processes. Linear correlation tests were used for the anexine V and Mitosensor ratios. RESULTS: Due to the study's design, some differences were observed regarding the displacement parameters and the presence of apoptosis, both, in the plasmatic membrane and in mitochondrial membrane potentials. A positive correlation between both, mitochondrial and cytoplasmic membrane functions was also found. CONCLUSIONS: This is the first study performing a comparative analysis between mitochondrial membrane function and cytoplasmatic PS expression as early cellular death markers. The male infertility population is probably associated with an increase in this kind of apoptosis processes.

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

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.

[Correlation between follicle levels of superoxide dismutase and oocyte quality, fertilization rates and embryo development]. / Correlación entre las concentraciones intrafoliculares de la superóxido dismutasa y la calidad ovocitaria, las tasas de fertilización y el desarrollo embrionario.

BACKGROUND: The intraovarian oxidative balance is important during oocyte development, and fertilization. It has been proposed that one of the most important enzymes in the follicle is the superoxide dismutase (SOD). OBJECTIVE: To correlate levels and percentage of SOD activity in follicular liquid with quality, fertilization and embryo development in a group of patients submitted to in vitro fertilization. MATERIAL AND METHODS: We obtained 120 follicular liquids from oocytes aspirated in 41 patients during an IVF program and then we followed the development of each oocyte separately. We measured the activity and concentration of SOD in the follicular liquid, and we evaluated the following variables: quality and maturity in the oocytes, as well as fertilization rate, segmentation rate and pregnancy. The statistical analysis was made with ANOVA test and Pearson test. RESULTS: In the analysis of the results, we observed a higher percentage of activity in the SOD in oocytes with good quality (3 and 4) in comparison with poor quality oocyte (1 and 2) (89 and 82% vs 75 and 61% p<0.05). We observed higher concentrations and activity of SOD in oocytes with a good fertilization rate and segmentation (p<0.05). When we analyzed the variables in function of pregnancy, we observed that the embryos that were transferred and developed pregnancy had higher concentrations and activity of SOD than embryos that did not develop pregnancy. CONCLUSIONS: Elevated levels and high percentage in the activity of SOD are associated with a better quality in the oocyte, and a good embryo development, influenced by the oxidative balance.

[Initial values of human chorionic gonadotropin as a prognostic variable of pregnancy evolution in assisted reproduction]. / Valores iniciales de la gonadotrofina coriónica humana como pronóstico de la evolución del embarazo en reproducción asistida.

INTRODUCTION: In assisted reproduction programs, once a pregnancy has been achieved, the power of predicting its evolution is important for the medical team as well as for the patient. The determination of pregnanediol or of placental protein 14 levels has been postulated as a predictive factor, however, the determination of hCG is, seemingly, the most adequate parameter for the detection of early developmental alterations during pregnancy. OBJECTIVE: To determine those predictive values of hCG which establish a prognosis concerning the evolution of pregnancy through the analysis of the values of this hormone on post-transference days 14 and 16, as well as to determine hCG values for multiple pregnancies. MATERIAL AND METHODS: Data from 88 patients participating in the in vitro fertilization program, in whom pregnancy was achieved, were retrospectively analyzed, and hCG levels were determined on post-transference days 14 and 16. Results were analyzed by the ANOVA test in order to compare mean values, & ROC were used to determine sensitivity and specificity. RESULTS: The patients were divided in three groups: 1) pregnant for more than 26 weeks; 2) pregnant for less than 26 weeks; and 3) chemical pregnancy. Significant differences in hCG levels on post-transference days were observed among these groups of patients. The levels of hCG, on post-transference day 14, 113 IU/L, and on day 16, 403 IU/L, presented, respectively, an 80% and 79% specificity, while the greater than 200.33 IU/L hCG increase offers a sensitivity and specificity of 80% and 83%, respectively, for a pregnancy of more than 26 weeks. In order to consider hCG levels as predictive for a high fetal order pregnancy, it was observed that hCC levels of 270.42 UI/L on day 14 present a sensitivity of 91% with a specificity of 64%, and levels higher than 837.14 IU/L on day 16 offer a sensitivity and specificity of 91% and 62%, respectively. CONCLUSIONS: The determination of hCG levels greater than 113 IU/L on day 14 and greater than 403 IU/L on day 16 offer adequate sensitivity and specificity as predictive factors for pregnancy evolution beyond the 26 GW, while hCG levels of 270.42 and 837.14, respectively, on days 14 and 16 offer a very high sensitivity (91%) for multiple pregnancy.

[Azoospermia : In vitro fertilization results, using testicular biopsy and cryopreserved spermatozoa]. / Azoospermia: resultados en reproducción asistida con el uso de biopsia testicular y espermatozoides criopreservados.

Testicular sperm extraction (TESE) by open testicular biopsy, has become, since the introduction of the ICSI in 1992, the corner stone in treatment for azoospermia. This study reports the outcome of patients with open testicular biopsy for ICSI procedure indicated by azoospermia. 16 patients with azoospermia (12 obstructive and 4 non obstructive). The open testicular biopsy was performed prior the controlled ovarian hyperstimulation (COH) protocols of their couples, in two of the 16 patients no sperm were found in the biopsy, and the other 14 patients were admitted to 18 ICSI cycles, and the testicular samples were cryopreserved until oocyte capture. The controlled ovarian hyperstimulation (COH) was individualized in each case in accordance to the characteristics of each patient: 12 patients were used the long luteal phase GnRH agonist protocol, ultrashort protocol (Flare up) in one patient, GnRH antagonist in four, and the last one with endometrial preparation for cryopreserved embryo transfer. The mean of oocytes recovered was 11.71 +/- 7.24 oocytes per patient with a recovery rate of 72.64%. The fertilization rate was 49.35 +/- 29.24 and were transfered an average of 3 embryos per patient with a range between 1 and 5 embryos. In 18 cycles, 7 pregnancies occurred, four singles, one twin, one triple and one biochemical pregnancy. In conclusion the testicular sperm extraction (TESE) by open testicular biopsy is a good option for patients with azoospermia usually it achieves an adequate sample of testicular tissue with high possibilities of sperms recovery, in our study we obtained appropriate sperms in fourteen of sixteen patients for the ICSI procedure with good fertilization and pregnancy rates.

[Fertilization rate analysis as a predictive variable for an in-vitro fertilization program success]. / Análisis de la proporción en la tasa de fertilización como una variable predictiva del éxito en un programa de fertilización in vitro.

OBJECTIVE: Determining if fertilization rates can be used as a predictive factor for pregnancy induction in ETIVF-ICSI programs. TYPE OF STUDY: Retrospective, observational and descriptive. MATERIALS AND METHODS: Six hundred and seventy nine cycles of the in vitro fertilization program, using long protocol hypophyseal suppression, stop, or antagonsits, were included. Ovarian stimulation was carried out with menotropines or recombinant FSH. Those patients whose cycle was stopped due to the lack of follicular development were excluded. Variables under study were: age, fertilization percentage, pregnancy rate, pre-ovulatory estradiol levels, number and quality of captured oocytes, transferred embrios and endometrial thickness on the day of transference and the presence of pregnancy. The Pearson P Test with a 95% confidence interval and the Student T Test used to establish differences with a 95% confidence interval statistical analyses were applied. RESULTS: Six hundred and seventy nine cycles were studied, 487 of which used the conventional fertilization method, and 192 used the ICSI method. Mean age among patients was 34 +/- 1.1 years old, with pre-ovulatory estradiol levels of 4,023 +/- 1,134 pg/mL, the average quantity of captured oocytes was 11.7 +/- 3.2 with a capture rate of 69.6%. Mean fertilization rates averaged 54% with a 20.7% pregnancy rates using the transference method. After analyzing the fertilization rate in each group, a statistically significant linear correlation was observed (P = 0.547, CI 95%) with the pregnancy rate. After assigning patients to two different groups: conventional IVF and ICSI, a higher positive correlation was observed (P = 0.827, CI 99%) in the first group. No significant differences were observed in the remaining parameters between both groups, excepting oocyte maturity, where greater prophase I and metaphase II percentages were observed in the ICSI group. When 50% fertilization was taken as the cutting point, a 78.19% negative predictive value was determined, with a 25% positive predictive value, 77.5% sensitivity, and 25.6% specificity. CONCLUSIONS: A fertilization percentage greater than 50% can be used as a pregnancy predicting factor in in vitro fertilization programs.