Correlação da maturação e da morfologia do oócito humano com as características do fuso meiótico e da zona pelúcida

Nas últimas décadas, alguns parâmetros laboratoriais têm sido propostos para identificar o potencial de saúde oocitária em Reprodução Assistida: 1. Maturidade nuclear e citoplasmática (pesquisa); 2. Dismorfismo (anomalias intracitoplasmáticas); 3. Fertilizaçao. Habitualmente, esses parâmetros (exceto a maturação citoplasmática) são avaliados pelo simples emprego de sistemas de microscopia de luz convencional. Nos últimos oito anos, foram relatados diversos estudos em oócitos humanos sobre a birrefringência da zona pelúcida (BF-ZP), a espessura da ZP, e a visualização do fuso meiótico (FM). Entretanto, ainda é discutível o poder desses novos parâmetros na seleção de óvulos com o pontecial de originar embriões com taxas de implantação elevadas, além disso, seu sistema de visualização e quantificação é complexo e dispendioso. O objetivo deste estudo foi investigar uma possível correlação entre esses parâmetros tradicionais com a BF-ZP, espessura da ZP e o FM. Dessa forma, um total de 73 pacientes que participaram do programa de injeção intracitoplasmática de espermatozóide (ICSI) no Centro de Reprodução Humana “Prof Franco Júnior” tiveram seus óvulos avaliados quanto a maturação nuclear (n=83), maturação citoplasmática (n=29), dismorfismo (n=280) e fertilização (n=216) sendo os resultados correlacionados com a imagem do FM (presença ou ausência), a intensidade da BF-ZP (positiva ou negativa) e a espessura da ZP. Os dados finais revelaram uma fraca correlação entre a maturação, o dismorfismo e a fertilização oocitária com a imagem do FM, a intensidade da BF-ZP, e a espessura da ZP. Entretanto, esses parâmetros poderiam ser responsáveis por identificar pontos biológicos diferentes do potencial de qualidade oocitária. Assim sendo, seria uma medida coerente, a utilização desses parâmetros, em forma conjunta, através de um escore de qualidade oocitária.During the last decades, three laboratorial parameters have been proposed to identify the potential of the oocyte quality in ART: 1- Nuclear and cytoplasmic maturation; 2-Dysmorphims (intracytoplasmic abnormalities); 3 - Fertilization. These parameters (except the cytoplasmic maturation) are assessed by a simple system of conventional light microscopy. In the last eight years, numerous studies about zona pellucida birefringence (BF-ZP), zona pellucida thickness and meiotic spindle visualization have been reported. However, it is still controversial the power of these parameters in selecting oocyte with potential to develop into implantation-competent embryos. Furthermore, the microscopy system is complex and expensive. The present study aims to evaluate whether there is any correlation between the classical parameters with BF-ZP, ZP thickness and spindle image. A total of 73 patients who participated in an ICSI program had their oocytes evaluated such nuclear maturation (n=83), cytoplasmic maturation (n=29), dysmorphism (n=280) and fertilization (n=216) being its results correlated to the spindle image (presence or absence), BF-ZP intensity (positive or negative) and ZP thickness. The final results showed a low correlation between maturation, dysmorphism and fertilization compared to spindle image and ZP characteristics (BF-ZP, ZP thickness). However, these factors can be responsible to identify specific biological differ from the oocyte potential. Concluding, the use of these factors in association, as a score (oocyte quality score), could be the correct evaluation

Correlação entre a taxa de fertilização e o fuso meiótico em oócitos humanos: Uma meta-análise

Objective: To investigate the relationship between the presence of meiotic spindle in human oocytes and fertilization rates in ICSI cycles. Methods: Search strategies included online surveys of databases from 1990 to 2008. Nine trials fulfilled the inclusion criteria Results: According to the meta-analysis, the results showed statistically significant higher fertilization rate (p<0.0001) when the meiotic spindle was viewed than when it was not. There was heterogeneity in this comparison. Conclusion: The presence of a birefringent meiotic spindle in human oocytes can predict a higher fertilization rate. This observation has clinical relevance mainly in countries where there is a legal limit on the number of oocytes to be fertilized. Copyright - SBRA - Sociedade Brasileira de Reprodução Assistida

Laser-assisted hatching of cryopreserved-thawed embryos by thinning one quarter of the zona

Laser-assisted hatching is little documented in the literature regarding its efficacy in cryopreserved-thawed (CT) embryo transfer cycles. The aim of the present study was to evaluate in a randomized manner the efficacy of thinning one quarter of the zona pellucida of CT embryos to a depth of 50-80% of the original thickness, via laser treatment (the qLZT-AH procedure), in improving implantation and pregnancy rates. Two populations were studied: population I, patients who had all their supernumerary embryos cryopreserved, regardless of their morphology, and population II, patients at risk of ovarian hyperstimulation syndrome who had all their embryos cryopreserved. Artificial and natural protocols were used for the embryo transfers. A total of 350 laser-thinned CT embryos were compared with 352 intact zona embryos. No difference in implantation or pregnancy rate was found after using qLZT-AH in either population. These findings suggest that qLZT-AH should not be routinely performed in cryopreserved embryo programmes

Determinação precoce do sexo fetal pela análise do DNA no plasma materno

Purpose: to verify the viability of early diagnosis of fetal gender in maternal plasma by the real-time polymerase chain reaction (real-time PCR) starting at the 5th week of pregnancy. Methods: peripheral blood was collected from pregnant women with single fetus starting at the 5th week of gestation. After centrifugation, 0.4 mL plasma was separated for fetal DNA extraction. The DNA was analyzed in duplicate by real-time PCR for two genomic regions, one of the Y chromosome and the other common to both sexes, through the TaqMan® method, which uses a pair of primers and a fluorescent probe. Patients who aborted were excluded. Results: a total of 79 determinations of fetal DNA in maternal plasma were performed in 52 pregnant women. The results of the determinations were compared to fetal gender after delivery. Accuracy according to gestational age was 92.6% (25 of 27 cases) at 5 weeks with 87% sensitivity, and 95.6% (22 of 23 cases) at 6 weeks with 92% sensitivity. Starting at the 7th week of pregnancy, accuracy was 100% (29 of 29 cases). Specificity was 100% regardless of gestational age. Conclusion: real-time PCR for the detection of fetal gender in maternal plasma starting at the 5th week of gestation has good sensitivity and excellent specificity. There was agreement of the results in 100% of the cases in which male gender was diagnosed, regardless of gestational age, and from the 7th week of gestation for female gender diagnosis

Correlation between semen analysis by motile sperm organelle morphology examination and sperm DNA damage

Regression analysis of 538 semen samples demonstrated that percentages of normal nuclear sperm and all spermatozoa with abnormalities of nuclear form at high magnification had significant negative correlation with percentages of DNA fragmentation. on the other hand, there was a positive correlation between percentages of spermatozoa with nuclear vacuoles and those with DNA fragmentation. (Fertil Steril (R) 2010;94:1937-40. (C) 2010 by American Society for Reproductive Medicine.