Birth after low-level +20 Aneuploid Mosaic Embryo Transfer: A Case Report.

OBJECTIVE: Recently, it has been discussed whether or not mosaic embryo transfers should be performed since they might result in viable pregnancies, although they often end up being discarded. We report a case of successful pregnancy, after a mosaic embryo transfer from an in vitro matured egg and frozen PESA sperm. CASE DESCRIPTION: Tests performed on a female aged 40 years and a male aged 37 years seeking fertility treatment found she had an adequate ovarian reserve and patent fallopian tubes. He had a history of cryptorchidism and inguinal hernia repair. The spermogram showed azoospermia, and testicular ultrasound showed an atrophic left testicle and a normal right testis. The vas deferens was palpated during physical examination. Intracytoplasmic sperm injection with percutaneous epididymal sperm aspiration (PESA) was indicated. Two cycles of IVF after controlled ovarian stimulation with follitropin delta was performed. In the first cycle, seven mature eggs were inseminated, two fertilized normally, resulting in one blastocyst biopsied and analyzed by NGS with complex aneuploid results. In the second cycle, frozen sperm from PESA was used. Three eggs were inseminated on the day of the procedure (resulting in 2 blastocysts), and three in vitro matured eggs were inseminated after 24 hours (resulting in 1 blastocyst). NGS analysis showed two complex aneuploid embryos and one 40% low-level trisomy 20 aneuploid mosaicism (+20) for the post 24-hour embryo. A mosaic embryo transfer was performed, resulting in clinical pregnancy and birth of a healthy baby girl with a normal blood karyotype. DISCUSSION: Mosaic embryo transfer is a topic for discussion. Certain levels of mosaicism do not seem to pose risks to the development of the fetus.

Is there a better evolutionary outcome in a 4-cell tetrahedron embryo?

With the growing understanding of in vitro fertilization and reproductive technology, the magnitude of studies related to embryonic evolution has also increased. The optimization of embryo selection is crucial to minimize the risk of multiple pregnancies and to guarantee successful implantation and pregnancy. On the second day of culture, the four-cell embryo can be shaped into different arrangements, such as tetrahedral and planar. Previous studies have shown that mammalian embryos have a tetrahedral shape and that any deviation from this ideal configuration can negatively affect blastocyst development. A few studies have also found that planar embryos would be linked to negative predictors of success for reaching the blastocyst stage and its good quality. Therefore, it seems that tetrahedral should be preferred over planar-shaped embryos for embryonic transfers, but there is still little understanding and evidence about this subject. Thus, the objective of the present paper was to review the available literature on study tendencies to compare tetrahedral and planar-shaped embryos considering their effect on implantation and pregnancy results.

Sazonalidade e qualidade do sêmen fresco e criopreservado de touros Pantaneiro e Nelore / Seasonality and quality of fresh and cryopreserved semen of Pantaneiro and Nellore bulls

Objetivou-se avaliar o efeito da estação do ano sobre a qualidade do sêmen fresco e criopreservado de reprodutores Pantaneiros (Bos taurus) criados em condições tropicais. Foram utilizados 7 touros Pantaneiros e 3 Nelores (controle), dos quais foi aferido circunferência escrotal, consistência testicular e após a coleta e congelamento do sêmen realizada análise de motilidade, vigor, defeitos menores, maiores e totais, concentração, integridade de membrana plasmática e acrossomal para sêmen fresco e além destas, estresse oxidativo para sêmen criopreservado. O experimento foi conduzido em delineamento inteiramente casualizado, e arranjo fatorial 2x2 (2 raças e 2 estações do ano). A raça, estação do ano ou a interação entre eles, não alteraram significativamente as médias de circunferência escrotal, consistência testicular, motilidade, vigor, concentração, integridade de membrana acrossomal e porcentagem de defeitos menores. A integridade da membrana plasmática no sêmen fresco sofreu efeito da estação do ano e foi menor no inverno em ambas raças (95,76 ± 1,77% vs. 87,07 ± 4,78% P=0,03). A estação do inverno aumentou a porcentagem de defeitos maiores (29,15% vs. 16,44%, P<0,01) e totais (17,49% vs. 30,45%, P<0,01). Os parâmetros do sêmen congelado não foram influenciados pela raça, estação do ano ou interação entre elas. Portanto, nas condições edafoclimáticas estudadas, os reprodutores Pantaneiros apresentaram redução na sua qualidade seminal na estação do inverno.

The aim of the present study was to evaluate the effect of seasonality on the quality of fresh and cryopreserved semen of Pantaneiro breed (Bos taurus) bulls raised under tropical conditions. Scrotal circumference and testicular consistency were performed in seven Pantaneiro and three Nellore (control) bulls. Sperm motility, vigor, minor, major and total defects, concentration, plasma and acrosomal membrane integrity were assessed in fresh and post-thawed semen. Additionally, oxidative stress was determined in post-thawed semen samples. The experiment was done in a complete randomized design, with a 2x2 factorial arrangement (2 breeds and 2 seasons). Breed, season of the year or the interaction of both did not alter scrotal circumference, testicular consistency, motility, vigor, concentration, acrosomal membrane integrity and percentage of minor defects (P<0.05). Plasma membrane integrity of fresh semen was affected by the season and was smaller in winter in both breeds (95.76 ± 1.77% vs 87.07 ± 4.78%, P=0.03). Nevertheless, also in the winter there was an increase in the percentage of major (29.15% vs 16.44%, P<0.01) and total defects (17.49% vs. 30.45%, P<0.01) in fresh semen samples. Breed, season or interaction of both did not influence the sperm parameters of cryopreserved semen. Thus, in the studied climatic conditions, the Pantaneiro breed bulls present decrease in semen quality mainly in the winter season

Avaliação do tocoferol no congelamento do sêmen bovino e nas taxas de prenhez após inseminação artificial em tempo fixo / Tocopherol evaluations at the freezing of bovine semen on the pregnancy rates after fixed time artificial insemination

O presente estudo avaliou se a adição de tocoferol no diluidor para a criopreservação de sêmen bovino reduz os danos causados pelo estresse oxidativo e melhora a capacidade fertilizante do sêmen utilizado na IATF. No primeiro lote sincronizado foram utilizadas 84 fêmeas Nelore (Bostaurusindicus) e no segundo lote 44 fêmeas. Para a inseminação artificial as vacas foram divididas aleatoriamente em dois grupos: controle (inseminadas com sêmen criopreservado sem uso de aditivos) e tocoferol (inseminadas com sêmen criopreservado com adição de 10mmol/mLtocoferol). Foram utilizados sêmen de três reprodutores da raça Nelore (Bos taurus indicus), sendo as doses provenientes de uma única partida, distribuída aleatoriamente entre as fêmeas inseminadas. O diagnóstico de gestação foi realizado 35 dias após a IATF por exame ultrassonográfico retal. O experimento foi realizado em delineamento inteiramente casualizado, e a taxa de prenhez comparada pelo teste qui-quadrado. A adição de 10mmol/mL de tocoferol no diluidor do sêmen não influenciou (P>0,05) na taxa de prenhez após IATF em comparação ao grupo controle (sem aditivos) para as médias do primeiro lote sincronizado (n=84; 38,5% vs 40%), segundo lote sincronizado (n=44; 28% vs 31,6%) e para a média geral dos lotes (n=128; 34,4% vs 37,5%). Nas condições experimentais a adição de 10mmol de tocoferol ao meio crioprotetor do sêmen não melhorou a taxa de prenhez após a inseminação artificial em tempo fixo na espécie bovina.

The present study evaluated if the addition of tocopherol to the extender semen cryopreservation reduces the damage caused by oxidative stress and preserves the fertilizing capacity of semen used in FTAI. In the first lot we used 84 synchronized females Nelore (Bos taurus indicus) and the second lot 44 females.For the artificial insemination the cows were randomly divided into two groups: control (inseminated with semen cryopreserved without using additives) and treatment (inseminated with semen cryopreserved with added 10 mmol/ml tocoferol). We used three semen sires Nelore (Bos taurus indicus), with doses starting from a single, randomly distributed among females inseminated. The pregnancy diagnosis was done 35 days after FTAI by rectal ultrasonography. The experimental design was completely randomized and pregnancy rates compared by chi-square test. There were no effect (P> 0.05) in pregnancy rate using cryopreserved semen with added 10mmol/ml tocopherol in the bovine semen extender compared to the control group (no additives) in the first synchronized group (n = 84, 38.5% vs 40%), in the second synchronized group (n = 44, 28% vs 31.6%) and the all animals (n = 128, 34.4% vs 37.5%). We conclude that, under the experimentalconditions, the addition of 10 mmol of tocopherol in the semen extender did not improve the pregnancy rate after FTAI in the bovine species.