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Our main objective was to identify the male and female parameters associated with total fertilization failure (TFF) in IVF with nonmasculine indications. The present work, IRB equivalent INS 63209, is a case-control study that evaluated all cases with TFF after conventional IVF at the Center for Human Reproduction from January 2010 to December 2019 (n = 154). As a control group, we analyzed all patients who did not experience fertilization failure after conventional IVF in the same period (n = 475). We evaluated various parameters, both male and female, assessed during infertility treatment, and only cases without masculine etiology (normal seminal parameters) were included. Ages (female and male) were not different between the groups. Moreover, AMH (anti-Müllerian hormone), semen volume, preprocessing concentration and preprocessing motility were not significantly different (P > 0.05). However, the number of collected oocytes (study versus control groups, median [25-75 interquartile]: 2 [1-5] and 5 [3-8]); MII (2 [1-4] and 5 [2-7]); and postprocessing motility (85 [70-90] and 90 [80-95]) were significantly different between both groups (P < 0.05). Furthermore, a logistic regression analysis including all significant data demonstrated that the number of collected oocytes was significantly related to IVF failure. Patients with fewer than 5 oocytes had an OR of - 1.37 (- 0.938 to - 1.827) for TFF after conventional IVF. Our results showed that a lower follicular response to controlled ovarian stimulation, evidenced by a decreased number of collected oocytes, was the most important parameter associated with IVF failure in nonmasculine infertility.

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Introduction Chlamydia trachomatis (CT) has been related to fallopian tube damage and infertility. Its prevalence in the population that attend public services is known; however, there is scant data on this factor in private infertility clinics. The objective of this study is to verify the prevalence of CT among women attending a private in vitro fertilization (IVF) reference clinic in southern Brazil. Methods This is a cross-sectional study carried out between January 1, 2019, and August 30, 2021, at an IVF private clinic in southern Brazil. Infertile women between 18 and 50 years old, who provided a morning urinary sample for reverse transcription-polymerase chain reaction (RT-PCR) test for CT analysis, were included in the study. The variables studied included the patient's age, body mass index (BMI), duration of infertility, type of infertility, indication for IVF, and detection or not of CT in the urine. Results The prevalence of CT was 10.84% (22 out of 203; 95% CI: 7.27-15.87). Patients with secondary infertility were older and had more ovarian and tubal factors compared to cases of primary infertility. The tubal factor was the most prevalent (27.3% in women with primary infertility and 35.8% in those with secondary). Time of infertility and BMI were similar between groups. Our results are derived from a single private IVF clinic which reduces the external validity. Conclusion The prevalence of 10.84% of CT in this population raises the importance of screening for sexually transmitted infections for proper treatment and to achieve better IVF outcomes.

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Oocyte quality could be negatively affected by many factors including smoking, alcohol consumption, obesity, woman's age, endometriosis and controlled ovarian stimulation (COS), during assisted reproductive technology (ART), in addition to genetic factors, such as hormone receptor polymorphisms, for example. We know that the increase in the reactive oxygen species (ROS) due to systemic disorders causes biochemical and morphological changes to the oocytes, interfering with their quality. The oocyte dysmorphism can be expressed through intra and/or extra cytoplasmic changes. In general, the size and number of oocytes' morphological abnormalities are directly related to preimplantation development failure. This case report is based on four in vitro fertilization (IVF) cycles performed by a patient with oocyte dysmorphism in all oocytes captured. The literature review on this topic aims to relate the characteristics of the oocytes, presented in the case report, with research results about the quality and morphology of the oocytes.

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In this report, we present an unusual case of a couple who achieved a successful pregnancy by ICSI with a single oocyte collected. The cumulus-oocyte-complex (COC) was retrieved at 36.5 hours post trigger, and was found to be at metaphase II, when sperm injection was performed at around 39 hours post trigger. At 18 hours post injection, the single oocyte was fertilized, developed to four-cell embryo on day 2, and 8-cell grade on day 3, when it was relocated in the uterine cavity. The pregnancy yielded a positive ß-hCG result. The scan performed at seven weeks, revealed the presence of one amniotic sac with a fetal heartbeat. The ongoing pregnancy has been eventless at 24 weeks of gestation.

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The pterostilbene (PT) molecule is a phytoalexin with a reducing effect on reactive oxygen species (ROS) and with a capacity to block lipogenesis. However, the potential reducing effects of PT on equatorial lipid accumulation and ROS have not yet been elucidated for in vitro-derived bovine embryos. The present study evaluated the effects of concentrations of 3, 1, 0.33, 0.11 µM PT, and a vehicle group on the percentage of cleaved embryos, embryos with more than 6 cells, percentage of blastocyst on Day 7 and 8, percentage of transferable embryos on Day 7, the cell count and relative concentration of lipids. In the second experiment, the effects of 0.33 µM PT and a vehicle group within two different O2 environments (5% and 20%) were evaluated for ROS generation and the percentage of Day 8 blastocysts. In the first experiment, no significant differences were found between the treatments with PT and the vehicle group (p > .05) concerning the percentage of cleaved embryos and embryos with more than 6 cells. Lipid reduction was observed in the groups treated with PT versus the vehicle group (p < .05). The vehicle group showed a higher rate of blastocyst production on Days 7 and 8 (p < .05) and an increase in the percentage of transferable embryos on Day 7 compared to the PT treatment groups (p < .05). Cell counts were not significantly different between treatments with PT and the vehicle group (p > .05). In the second experiment, the O2 concentration did not significantly affect ROS generation (p > .05); however, the groups treated with PT (0.33 µM) had a reduction in ROS (p < .05). The O2 concentration also did not significantly affect the rate of blastocyst production on Day 8 (p = .7696). Future research should be conducted to ascertain whether the reduction of lipids could enhance the cryopreservation and post-thaw viability of PT-treated embryos.

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OBJECTIVE: To determine the effect of fresh IVF/ICSI cycles on FET cycle embryo and pregnancy outcomes. METHODS: This retrospective cohort study included data from the medical records of 104 FET cycles performed from January 2014 to December 2016. Embryos were previously vitrified and then thawed for embryo transfer. Statistical significance was established at p<0.05. The main endpoints were FET cycle survival and pregnancy rates. RESULTS: A total of 104 FET cycles were analyzed for survival; 94 showed good progression and 84 achieved embryo transfers. Patients with secondary infertility achieved significantly higher pregnancy rates - 6/38 (15.8%) vs. 18/46 (39.1%) (p<0.018). Stimulation with FSH/LH resulted in more significant embryo progression, 38/48 (79.2%) vs. 28/46 (60.9%) in the FSH group (p=0.01). Patients who got pregnant from fresh cycles had the highest pregnancy rates in FET cycles (p<0.0001). Lower numbers of frozen embryos correlated with higher pregnancy rates (p=0.048). Embryos frozen on day 2 or 3 had the most significant progression (p<0.0001). Freeze-thaw intervals >12 months yielded higher pregnancy rates, 13/30 (43%), vs. 11/54 (20.4%) (p=0.025). CONCLUSION: Patient pregnancy in fresh cycles is a good prognostic factor for FET cycle success. Delaying FET by more than 12 months might result in higher pregnancy rates.

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Preimplantation genetic testing (PGT) for in vitro fertilization (IVF) - also known as PGT for Structural Rearrangements (PGT-SR) - has emerged as an option for at-risk couples carrying balanced translocations. The female in the couple featured in this case report is a carrier of a balanced reciprocal translocation who underwent IVF. PGT showed all her embryos were aneuploid. She subsequently had two cycles using donor oocytes, which ended in miscarriages.

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Resumen OBJETIVO: Evaluar los desenlaces en la recuperación de ovocitos y la tasa de embarazo en pacientes en protocolo de fertilización in vitro de acuerdo con las concentraciones de hormona antimülleriana y la edad de la mujer. MATERIALES Y MÉTODOS: Estudio restrospectivo, transversal, comparativo y observacional efectuado en pacientes en tratamiento de fertilización in vitro en un centro privado de reproducción asistida (enero 2013-enero 2018). La población se dividió en grupo 1 (concentraciones menores de 1 ng/mL de hormona antimülleriana) y grupo B (concentraciones mayores de 1 ng/mL de hormona antimülleriana) para determinar la asociación entre la edad y las concentraciones de hormona antimülleriana y la respuesta a la cantidad de ovocitos recuperados y tasa de embarazo; estos grupos se subdividieron por edades (≤ 29, 30-34, 35-39 y ≥ 40 años). RESULTADOS: Se estudiaron 282 pacientes de las que se eliminaron 35 por expediente incompleto; quedaron 247; 93 en el grupo 1 y 154 en el grupo 2. En el grupo 1 se recuperaron 4.61 vs 7.9 ovocitos (p < 0.001). En las pacientes menores de 29 años con concentraciones de hormona antimülleriana menores de 1 ng/mL la cantidad promedio de ovocitos recuperados fue mayor: 7.8 ovocitos versus los otros grupos de edad con menos de 1 ng/mL. La tasa de embarazo en las pacientes con concentraciones de hormona antimülleriana mayores de 1 ng/mL fue mayor en los grupos de edad menores de 29 años y de 30 a 34 años (p < 0.01). CONCLUSIONES: Independientemente de la edad, cuando las concentraciones de hormona antimülleriana son mayores de 1 ng/mL se logra recuperar mayor cantidad de ovocitos que en quienes tienen menos de esa concentración. Las pacientes menores de 35 años con concentraciones de hormona antimülleriana mayores de 1 ng/mL tienen mayor tasa de embarazo que las de menos de 1 ng/mL. Cuando la edad de la mujer es mayor de 35 años las concentraciones de hormona antimülleriana no influyen en las tasas de embarazo.

Abstract OBJECTIVE: To evaluate the outcomes in oocyte retrieval and the pregnancy rate in patients under in vitro fertilization protocol according to anti-Müllerian hormone concentrations and the age of the woman. MATERIALS AND METHODS: Retrospective, cross-sectional, comparative and observational study carried out in patients undergoing in vitro fertilization treatment in a private assisted reproduction center (January 2013- January 2018). The population was divided into group 1 (lower concentrations of 1 ng / mL of antimülleriana hormone) and group B (concentrations higher than 1 ng / mL of antimülleriana hormone) to determine the association between the age and the antimülleriana hormone concentrations and the answer to the amount of recovered oocytes and pregnancy rate; these groups were subdivided by age (≤ 29, 30-34, 35-39 and ≥ 40 years). RESULTS: We studied 282 patients, of which 35 were eliminated due to incomplete records; there were 247; 93 in group 1 and 154 in group 2. In group 1, 4.61 vs 7.9 oocytes were recovered (p <0.001). In patients younger than 29 years old with antimüllerian hormone concentrations lower than 1 ng / mL, the average number of oocytes retrieved was higher: 7.8 oocytes versus the other age groups with less than 1 ng / mL. The pregnancy rate in patients with antimüllerian hormone concentrations greater than 1 ng / mL was higher in the age groups under 29 years and 30 to 34 years (p <0.01). CONCLUSIONS: Regardless of age, when antimüllerian hormone concentrations are greater than 1 ng/mL, more oocytes are recovered than in those less than that concentration. Patients younger than 35 years old with antimüllerian hormone concentrations lower than 1 ng/mL have a higher pregnancy rate than those less than 1 ng/mL. When the age of the woman is over 35 years old, anti-Müllerian hormone concentrations do not influence pregnancy rates.

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OBJECTIVE: To assess the sociodemographic profile and gynecologic and obstetric characteristics of women referred to a public reference center in Campinas, Brazil, for in vitro fertilization (IVF). METHODS: Women referred between April 1, 2008, and October 31, 2009, were eligible for inclusion in a cross-sectional study. Participants were interviewed about sociodemographic characteristics, obstetric and gynecologic history, and etiologic factors resulting in the referral. Preliminary clinical examinations performed elsewhere were evaluated. RESULTS: A total of 176 women were included, of whom 129 (73.3%) presented with tubal factor infertility. Tubal ligation had been performed in 66 (37.5%) women. Overall, 121 (68.8%) women were aged 30 years old or less, 110 (62.5%) had received more than 8 years of schooling, 123 (69.6%) had had infertility for up to 5 years, and 99 (56.3%) did not have any children. Moreover, 25 (14.2%) women had endometriosis and 25 (14.2%) had a male factor issue. A previous ectopic pregnancy was reported for 20 (11.4%) women and pelvic inflammatory disease for 49 (27.8%). CONCLUSION: Tubal factor infertility was the most common indication for IVF. Preventive measures are required, in addition to policies that ensure access to high-complexity treatments in the public sector.

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OBJECTIVE: To evaluate efficacy of Propofol at Cp 2.5 µg/ ml administered by Target Controlled Infusion (TCI) using Marsh Modified Model, in pre-medicated with midazolam/ fentanil Latin-American women (Venezuelans) during oocyte retrieval for In Vitro Fertilization. METHODS: Prospective, descriptive study included 72 women, 18-44 years old, ASA I-II, non obese, undergoing oocyte retrieval, pre-medicated with midazolam 0.04 mg/kg and fentanil 2µg/kg and received anesthesia based in Propofol at Cp 2.5µg/ml by Target Controlled Infusion using Marsh Modified Model. Demographic data, propofol doses, duration of procedure and recovery time was registered using descriptive statistic. Anesthesia efficacy was measured by Biespectral Analysis (BIS), Intra-Operative Movements Scale (0 to 5) graded, Postoperative Pain by Visual Analog Scale (VAS) and nausea/vomits incidence. ANOVA and Pearson Chi2 were used with an error of 0.05. RESULTS: Age average was 33.04±6 years old, procedure average time 18.06±8min, Propofol total doses 146.64±53 mgs, Propofol infusion doses average 155.2±3µg/Kg/min. During procedure, 70.8% of patients had no movement, 22.2% movement Grade I and 6.9% Grade II. (Grade I-II movement did not interfere with procedure continuity). 70.8% achieved BIS 40-50 and 93.1% had BIS equal o less than 60. There was a statistic significant correlation between BIS 40-50 and no movements. Recovery post-anesthesia time was 25.2±8 min. 98.6% of patients reported excellent comfort. CONCLUSION: With midazolam/fentanil pre-medication, Propofol at Cp 2.5µg/ml by TCI using Marsh Modified Model showed a 93% of effectiveness during oocyte retrieval in Latin-American women subjected to IVF, allowing an ultra- fast recovery time.

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The advent of in vitro fertilization (IVF) in animals and humans implies an extraordinary change in the environment where the beginning of a new organism takes place. In mammals fertilization occurs in the maternal oviduct, where there are unique conditions for guaranteeing the encounter of the gametes and the first stages of development of the embryo and thus its future. During this period a major epigenetic reprogramming takes place that is crucial for the normal fate of the embryo. This epigenetic reprogramming is very vulnerable to changes in environmental conditions such as the ones implied in IVF, including in vitro culture, nutrition, light, temperature, oxygen tension, embryo-maternal signaling, and the general absence of protection against foreign elements that could affect the stability of this process. The objective of this review is to update the impact of the various conditions inherent in the use of IVF on the epigenetic profile and outcomes of mammalian embryos, including superovulation, IVF technique, embryo culture and manipulation and absence of embryo-maternal signaling. It also covers the possible transgenerational inheritance of the epigenetic alterations associated with assisted reproductive technologies (ART), including its phenotypic consequences as is in the case of the large offspring syndrome (LOS). Finally, the important scientific and bioethical implications of the results found in animals are discussed in terms of the ART in humans.

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The Inter-American Court of Human Rights has ruled that the Supreme Court of Costa Rica's 2000 judgment prohibiting in vitro fertilization (IVF) violated the human right to private and family life, the human right to found and raise a family, and the human right to non-discrimination on grounds of disability, financial means, or gender. The Court's conclusions of violations contrary to the American Convention on Human Rights followed from its ruling that, under the Convention, in vitro embryos are not "persons," and do not possess a right to life. Accordingly, the prohibition of IVF to protect embryos constituted a disproportionate and unjustifiable denial of infertile individuals' human rights. The Court distinguished fertilization from conception, since conception, unlike fertilization, depends on an embryo's implantation in a woman's body. Under human rights law, legal protection of an embryo "from conception" is inapplicable between its creation by fertilization and completion of its implantation in utero.

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Objetivos: Conocer los resultados preliminares de tasa de embarazo por transferencia en las pacientes en quienes se realizó cultivo intravaginal de ovocitos-inyección intracitoplasmática de espermatozoides (INVO-ICSI) en un centro de fertilidad. Diseño: Estudio descriptivo de una serie de casos. Institución: Centro de Fertilidad Procrear, Lima, Perú. Participantes: Parejas con tratamiento de infertilidad. Intervenciones: Se analizó todos los 13 procedimientos de INVO-ICSI realizados en 12 pacientes desde diciembre 2011 a julio 2013. Para el estudio se utilizó el programa SPSS. Principales medidas de resultados: Tasa de gestación. Resultados: La edad promedio de la mujer fue 35,38 años ± 3,35, con promedio de búsqueda de embarazo de 2,25 años ±1,88. La causa de infertilidad en 46,2% era el factor masculino y en 53,2%, el factor femenino. En todos los ciclos se realizó transferencia de embriones. Se obtuvo un total de 5 gestaciones (38,46% por transferencia), de las cuales 3 fueron gestación única (60%) y 2 dobles (40%). Conclusiones: La tasa de embarazo por transferencia mediante el método INVO - ICSI fue comparable y aceptable frente a la de FIV/ICSI reportada en la literatura mundial.

Objectives: To determine preliminary results of pregnancy rate per transfer in patients undergoing intravaginal oocyte culture-intracytoplasmatic sperm injection (INVO-ICSI) at a fertility center. Design: Descriptive, series of cases study. Setting: Procrear Fertility Center, Lima, Peru. Participants: Couples with infertility treatment. Interventions: Thirteen INVO-ICVSI performed in 12 patients from December 2011 through July 2013 were reviewed. SPSS program was used. Main outcome measures: Pregnancy rate. Results: Womens average age was 35.38 years ± 3.35 and were seeking pregnancy 2.25 years ± 1.88 average. Infertility was due to male factor in 46.2% and to female factor in 53.2%. Embryo transfer was done in all cycles and 5 pregnancies were obtained (38.46% of cycles), 3 singleton (60%) and 2 double pregnancy (40%). Conclusions: INVO-ICSI fertilization rate was comparable and acceptable against other fertilization techniques.

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Objetivo: comparar la calidad embrionaria y describir las tasas de implantación, embarazo y aborto en las técnicas de fertilización in vitro (FIV) y el cultivo intravaginal de ovocitos. Materiales y métodos: cohortes históricas de pacientes con tratamiento de fertilización in vitro y el cultivo intravaginal de ovocitos en el Centro Colombiano de Fertilidad y Esterilidad (Cecolfes) durante el año 2010. Se incluyeron 137 pacientes aspiradas dentro de los cuatro grupos de estudio: Grupo 1, FIV/Incubadora; Grupo 2, FIV/INVO; Grupo 3, ICSI/INVO, y Grupo 4, ICSI/Incubadora. Se midió el peso de la paciente, el número de ovocitos recuperados y óvulos maduros (MII), la tasa de implantación y la tasa de embarazo y aborto en cada uno de los grupos. Se realizó análisis mediante la prueba de Kruskal-Wallis; la calidad embrionaria fue evaluada con un análisis de covarianza multivariado (MANOVA). Resultados: se observó diferencia significativa en la calidad embrionaria entre las dos técnicas FIV e INVO (p = 0,0388). En la técnica INVO se presentaron mayores tasas de división embrionaria (μ = 7,35/INVO frente a 6,64/Incubadora) y menor fragmentación (μ = 4,67/INVO frente a 4,59/ Incubadora). En cuanto a la tasa de implantación, embarazo y aborto se obtuvieron más altos porcentajes en los grupos INVO. Conclusión: la técnica INVO se asoció a mejor calidad embrionaria. Las tasas de implantación, embarazo y bajas tasas de aborto son semejantes a las descritas en la técnica FIV.

Objective: Comparing embryo quality and describing implantation, pregnancy and abortion rates regarding in vitro fertilization (IVF) and intravaginal oocyte culture (INVO) techniques. Materials and methods: The study involved historical cohorts of patients undergoing IVF and INVO treatment in the Colombian Fertility and Sterility Centre (Centro Colombiano de Fertilidad y Esterilidad – Cecolfes) during 2010. It involved 137 aspirated patients, covering four study groups: Group 1 IVF/incubator, Group 2 IVF/INVO, Group 3 ICSI/INVO and Group 4 ICSI/incubator. The patients’ weight, the number of ovocytes retrieved, mature ovules (M2), implantation rate, pregnancy and abortion rates were measured in each group. The Kruskal-Wallis test was used for statistical analysis; embryo quality was evaluated by multivariate covariance analysis (MANOVA). Results: A significant difference was observed regarding embryo quality between IVF and INVO (p = 0.0388), the INVO technique having higher embryo cleavage rates (μ = 7.35/INVO cf 6.64/ incubator) and lower embryo fragmentation (μ = 4.67/INVO cf 4.59/incubator). INVO groups also had higher percentages concerning their implantation, pregnancy and abortion rates. Conclusion: The INVO technique led to obtaining better quality embryos; implantation, pregnancy and abortion rates were similar to those described for the IVF technique.

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The Mycoplasma is considered cosmopolitan and can be disseminated through international trade of animals, industrialized semen and embryo transfer products. The expansion of cumulus cells is used as a parameter for evaluating cattle oocytes cultivated in vitro, and their morphological changes are representative. The aim of the present study was to evaluate the interaction of Mycoplasma bovigenitalium with primary-culture cumulus cells, after the in vitro maturation period. Cumulus complex oocytes (COCs) obtained through follicular puncture of ovaries from a cattle slaughterhouse were divided into two groups to be matured for 24 hours in the maturation medium (TCM 199 + hormones) in a climate controlled chamber at 38º C, 5% CO2, and 95% humidity. Subsequently, the oocytes were removed from the plates, which remained with only the cumulus cells attached. With the monostratum cell formed, one group was infected with 30 ºL (5 x 10(6) cells/mL) M. bovigenitalium, replicated in modified Hayflick medium at 37º C in a mycroaerofilic chamber, while the other was kept as a control. The results showed that with 24 hours of exposure to the pathogen, the cultures showed a small number of rounded and grainy cells, when compared to the controls. This effect persisted until the 7th day, when a process of cell detachment began. It can be concluded that a mycoplasma contamination may be imperceptible to the manipulations of FIV, because cells infected by this group of bacteria present no cloudiness in the culture field, and when they do not lyse the host cell, they make it more susceptible to environment and other infectious agents.

O Mycoplasma é considerado cosmopolita, podendo ser disseminado através do comércio internacional de animais, sêmen industrializado e de produtos de transferência de embriões. A expansão de células do cumulus é utilizada como parâmetro de avaliação de oócitos bovinos cultivados in vitro e suas alterações morfológicas são representativas. O objetivo deste trabalho foi avaliar a interação do Mycoplasma bovigenitalium, exposto experimentalmente à cultura primária de célula do cumulus, após o período de maturação. Complexos oócitos cumulus (COCs) obtidos através de punção folicular de ovários bovinos, provenientes de abatedouro, foram divididos em dois grupos para serem maturados durante 24h em meio de maturação (TCM199 + hormônios) em estufa a 38º C, 5% de CO2, 95% de umidade. Posteriormente, os oócitos foram retirados das placas, permanecendo somente com as células do cumulus aderidas. Com o monoestrato celular formado, um grupo foi infectado com 30 mL de M. bovigenitalium, replicado em meio Hayflick modificado a 37º C em estufa de microaerofilia, enquanto o outro foi mantido como controle. Os resultados mostraram que, com 24h de exposição ao patógeno, as culturas apresentaram um pequeno número de células arredondadas e granulosas, quando comparadas as dos controles. Esse efeito persistiu até o sétimo dia, onde se iniciou um processo de descolamento das células. Pode-se concluir que uma contaminação por micoplasma pode ser imperceptível às manipulações da FIV, pois células infectadas por esse grupo de bactérias não apresentam turvações no meio de cultura e, quando não lisam a célula hospedeira, tornam mais suscetível ao ambiente e outros agentes infecciosos.

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El objetivo de este estudio fue evaluar la capacidad de desarrollo in vitro de ovocitos bovinos de vacas mestizas B. taurus y B. indicus. Los ovocitos fueron recuperados de ovarios de hembras bovinas provenientes de un matadero comercial. Para la obtención de los complejos cumulus-ovocitos (CCO) se realizó la técnica de slicing, seleccionando los ovocitos que tenían al menos una capa de células del cumulus y un citoplasma homogéneo. Los ovocitos seleccionados fueron madurados y fecundados in vitro (MIV-FIV). Se utilizó semen de un toro Brahman puro (B. indicus). Para la evaluación de la MIV y FIV todos los ovocitos se fijaron por al menos 24 h a 4°C en solución metanol-ácido acético (3:1) y teñidos con aceto-orceína al 1,1%. La tasa de maduración de ovocitos de vacas con predominancia fenotípica B. indicus fue del 66,17% mientras que las vacas con predominancia fenotípica B. taurus alcanzaron un 50,94% (P>0,05). En cuanto a la tasa de fecundación se obtuvo un 14,28 y 35,72% de ovocitos penetrados normalmente y anormales, respectivamente, para el grupo de ovocitos con predominancia fenotípica B. indicus. Mientras que para vacas con predominancia fenotípica B. taurus, un 10,22% correspondió a ovocitos penetrados normales y 19,31% de ovocitos penetrados anormales, sin encontrar diferencias estadísticamente significativas en ambos grupos. Los presentes resultados, tanto para la progresión meiótica como para las tasas de fecundación, indican que los ovocitos de vacas mestizas con predominancia fenotípica B. indicus son más competentes en las primeras etapas de desarrollo in vitro que los ovocitos de vacas mestizas con predominancia fenotípica B. taurus.

The aim of this study was to evaluate the in vitro development capacity of bovine oocytes from crossbred B. taurus and B. indicus cows. Oocytes from bovine cows were collected from commercial slaughterhouse. The cumulus-oocyte complex (COC) ovaries were obtained by Slicing technique, selecting those oocytes that had 2 to 3 layers of cumulus cells and homogeneous cytoplasm. After selection oocytes proceed with maturation (IVM) and fertilization in vitro (IVF). It used semen from a pure Brahman bull (B. indicus). For the assessment of IVM as for IVF oocytes were fixed for about 24 hours at 4°C in methanol-acetic acid (3:1) solution and stained with 1.1% aceto-orcein. The maturation rate of oocytes from cows with B. indicus phenotypic predominance was 66.17%, whereas cows with B. taurus phenotypic predominance 50.94% (P>0.05). Fertilization rate obtained in B. indicus phenotypic predominance group was 14.28% of oocytes normal penetrated and abnormal penetrated 35.72%, for cows with a phenotypic predominance B. taurus oocytes normal penetrated were 10.22% and 19.31% of abnormal oocytes penetrated. In conclusion, the present results indicate that oocytes from cows with phenotypic predominance B. indicus are more competent in the early stages of development in vitro than oocytes from cows with phenotypic predominance B. taurus.