Análise multivariada da influência da contagem de folículos antrais e da idade sobre a probabilidade de sucesso da fertilização in vitro

Abstract

To determine whether the antral follicle count (AFC), assessed by transvaginal ultrasound on day 3 of the menstrual cycle, can predict the number of retrieved oocytes in patients undergoing ovarian hyperstimulation cycles for in vitro fertilization (IVF) and to correlate it with the maternal age and pregnancy rate. METHODS: This was a retrospective observational study based on a review of medical records from 193 patients who underwent assisted reproduction techniques between September 2010 and September 2012 at the Clinic for Human Reproduction Fecunda (Clínica de Reprodução Humana Fecunda) in Uberlandia, Minas Gerais State, Brazil. The study included women indicated for IVF who had follicle-stimulating hormone (FSH) levels below 10 mIU/ml on day 3 of the menstrual cycle. Oocyte recipients were excluded. The women were divided into 3 groups according to AFC (up to 10 follicles, 11 22 follicles, and 23 or more follicles). To compare the AFC groups with the group of patients who became pregnant, patients who had not developed oocytes and had not undergone embryo transfer were also excluded from the study. All patients were submitted to ovarian hyperstimulation treatments and transvaginal ultrasonographic evaluations for the AFC. Subsequently, oocyte retrievals and embryo transfers were performed. Spearman s correlation coefficient (sc) was used to measure the level of association between the numerical variables, and the chi-square test was used to compare pregnancy rates with the AFC. To assess the likelihood of pregnancy, we used a multivariate logistic regression that considered the AFC and age as independent variables; a 5% (p<0.05) significance level was adopted. RESULTS: Overall, 179 patients with a median age of 34 years were analyzed. When AFC was considered as the main variable, a positive correlation with the number of retrieved oocytes (sc = 0.48; p < 0.05) and a negative correlation with age (sc = -0.51; p < 0.05) were observed. There was no significant difference (p = 0.162) when the AFC groups were compared with the positive pregnancy test group; however, in the multivariate analysis, a cutoff of 27 antral follicles was observed, after which the probability of successful gestation tended to remain constant. CONCLUSIONS: There were greater numbers of retrieved oocytes with a higher AFC and fewer numbers of follicles and oocytes with increased age. The AFC can predict the likelihood of successful IVF.