[Polarized light microscopy for evaluation of oocytes as a prognostic factor in the evolution of a cycle in assisted reproduction]. / Microscopia de luz polarizada para evaluación de ovocitos como factor pronóstico en la evolución de un ciclo de reproducción asistida.

BACKGROUND: Identification of the best embryos to transfer is a key element for success in assisted reproduction. In the last decade, several morphological criteria of oocytes and embryos were evaluated with regard to their potential for predicting embryo viability. The introduction of polarization light microscopy systems has allowed the visualization of the meiotic spindle and the different layers of the zona pellucida in human oocytes on the basis of birefringence in a non-destructive way. Conflicting results have been reported regarding the predictive value in ICSI cycles. OBJECTIVE: To assess the predictive ability of meiotic spindle and zona pellucida of human oocytes to implant by polarized microscopy in ICSI cycles. MATERIAL AND METHODS: Prospective and observational clinical study. 903 oocytes from 94 ICSI cycles were analyzed with polarized microscopy. Meiotic spindle visualization and zona pellucida birefringence values by polarized microscopy were correlated with ICSI cycles results. RESULTS: Meiotic spindle visualization and birefringence values of zona pellucida decreased in a direct basis with increasing age. In patients aged over the 35 years, the percentage of a visible spindle and mean zona pellucida birefringence was lower than in younger patients. Fertilization rate were higher in oocytes with visible meiotic spindle (81.3% vs. 64%; p < 0.0001), as well as embryo quality (47.4% vs. 39%; p=0.01). Fertilization rate was higher in oocytes with positive values of birefringence (77.5 % vs. 68.5% p=0.005) with similar embryo quality. Conception cycles showed oocytes with higher mean value of zona birefringence and visible spindle vs. no-conception cycles (p<0.05). CONCLUSIONS: Polarized light microscopy improves oocyte selection, which significantly impacts in the development of embryos with greater implantation potential. The use of polarized light microscopy with sperm selection methods, blastocyst culture and deferred embryo transfers will contribute to transfer fewer embryos without diminishing rates of live birth and single embryo transfer will be more feasible.

[Effect of weight reduction on the clinical and hormonal condition of obese anovulatory women]. / Efecto de la reducción de peso en la condición clínica y hormonal de mujeres anovulatorias obesas.

Obesity is associated to a variety of endocrine abnormalities that might lead to chronic anovulation in women. Weight loss may improve the hormonal profile and then restore ovulation in some of them. The aim of the current study was to evaluate the effect of a weight loss program on the clinical and hormonal characteristics of anovulatory obese women attending our reproductive clinic. We studied a group of 30 anovulatory obese patients between 18 and 35 years old without any thyroid disease. Before and after a weight loss of at least 5% of initial body weight we analyzed LH, FSH, estradiol, prolactine, testosterone, dehydroepiandrosterone sulfate, oral glucose tolerance test and progesterone, weight, BMI, waist/hip ratio and total body fat percentage. The mean weight loss was 9.5 +/- 4.3 kg. which represents a weight loss of 10.96% from initial body weight, with 26 patients (86.6%) resuming spontaneous ovulation. The women's mean plasma testosterone, LH, estradiol and DHEA-S decreased significantly and there was significantly increased on progesterone. At the beginning a total of 12 patients showed an impaired oral glucose tolerance test and after weight loss 9 of them improved it. The results shown in this study demonstrate that even a small weight reduction and a decrease in total body fat percentage improve the hormonal profile and restore ovulation in anovulatory obese women. Thus weight loss should be considered before starting with ovulation induction therapy.

[Twin pregnancy after oocyte donation in a woman with Turner syndrome]. / Embarazo gemelar mediante la técnica de donación de ovocitos en una mujer con síndrome de Turner.

It is extremely rare for pregnancy to occur spontaneously in patients with Turner's syndrome, and if it happens this will have an increased risk of fetal wastage and congenital malformations in the new born, specially of the sexual chromosome. Oocyte donation is at present the technique of choice to release the reproductive wishes of these women. We present a case of a woman with Turner's syndrome, with a 45, X0 karyotype, to whom ovum donation and intrauterine embryo transfer were performed, obtaining a twin pregnancy without complications. A cesarean section was made at term, obtaining two healthy new born infants.