RESUMEN
OBJECTIVE: Comparing the follicular response in a group of patients with previous pelvic surgery submitted to in vitro fertilization. MATERIAL AND METHODS: Patients who were going to be submitted to controlled ovarian stimulation and in vitro fertilization were included. Two groups were formed: one with those patients who had had a previous pelvic operation and the other with those patients who had not. The characteristics which were analyzed included: age, weight, body mass index, FSH, LH and estradiol levels, as well as total ova numbers, grade of embryonic maturity, and number of transferred embryos. RESULTS: Ninety nine patients were studied: 46 had been submitted to pelvic surgery and 53 had not. Due to the design of the study there were no differences regarding age, weight, size and body mass index; the evaluation of the ovarian reserve was similar in both groups. However, the group of patients previously submitted to pelvic surgery presented a lower quantity of total ova (p = 0.004), less mature ova (p = 0.008) with a significantly lower pregnancy rate. CONCLUSIONS: Surgical procedures, combined with adherence processes, probably have a direct incidence on the characteristics of the perifollicular environment which interfere with adequate development of the ovum. All these can be observed in a decrease of fertilization processes and embryonic development, regardless of the expression of the adequate biochemical markers of the ovarian reserve. Our research shows that the group under study presents a decrease in follicular response affecting the quality of the ovum-embryo expressed in the pregnancy rate.