Analysis of meiotic abnormalities of in vitro matured oocytes from stimulated cycles of non-obese endometriotic and pcos patients: a pilot study

Abstract

OBJECTIVE: Endometriosis and Polycystic Ovarian Syndrome (PCOS) are major causes of human infertility. According to controversial data, both may be associated with worse outcomes of assisted reproduction techniques, which could be caused by an impairment of oocyte quality. Thus, we compared meiotic spindle morphology and chromosomal distribution of in vitro matured human oocytes from non-obese patients with endometriosis and PCOS submitted to ovarian stimulation for ICSI.DESIGN: A prospective, controlled study.MATERIALS AND METHODS: Infertile patients aged up to 38 years undergoing stimulated cycles for oocyte retrieval for ICSI were selected prospectively and consecutively and divided into endometriosis (20 patients) and PCOS (13 patients) groups. Immature oocytes (74 and 34 from endometriosis and PCOS patients, respectively) were submitted to in vitro maturation (IVM) for 19 hours ± 1 hour (GV) or 4 hours ± 30 minutes (MI) according to a maturation time curve determined before the beginning of the present study. Using immunostaining and fluorescence microscopy, we imaged spindle and chromosomal distribution of oocytes that extruded the first polar body after IVM.RESULTS: IVM rates were similar for both groups (53.1% and 50%, respectively, for the PCOS and control groups). Spindle and chromosome organization were observed in 35 and 17 oocytes from the endometriosis and PCOS groups, respectively. In the endometriosis group, 13 were normal MII oocytes (37.2%), 9 abnormal MII (25.7%), 11 normal telophase I (31.4%), and 2 normal telophase II (5.7%). In the PCOS group, 6 oocytes were normal MII (35.3%), 8 abnormal MII (47.1%), and 3 normal telophase I (17.6%). The proportions of normal MII oocytes were similar for the two groups (37.2% and 35.3% in endometriosis and PCOS groups, respectively).CONCLUSIONS: Our preliminary data demonstrate that in vitro maturation rates of immature oocytes obtained from stimulated cycles are similar in non-obese infertile women with endometriosis and with PCOS. In vitro matured oocytes from endometriotic patients have a higher percentage of TI when compared to PCOS patients. Our preliminary results also suggest that the incidence of meiotic anomalies, characterized by spindle rupture and/or chromosome misalignment, is similar in in vitro matured oocytes from non-obese PCOS and endometriotic patients. Both results will be better evaluated by increasing the present patient series. OBJECTIVE: Endometriosis and Polycystic Ovarian Syndrome (PCOS) are major causes of human infertility. According to controversial data, both may be associated with worse outcomes of assisted reproduction techniques, which could be caused by an impairment of oocyte quality. Thus, we compared meiotic spindle morphology and chromosomal distribution of in vitro matured human oocytes from non-obese patients with endometriosis and PCOS submitted to ovarian stimulation for ICSI. DESIGN: A prospective, controlled study. MATERIALS AND METHODS: Infertile patients aged up to 38 years undergoing stimulated cycles for oocyte retrieval for ICSI were selected prospectively and consecutively and divided into endometriosis (20 patients) and PCOS (13 patients) groups. Immature oocytes (74 and 34 from endometriosis and PCOS patients, respectively) were submitted to in vitro maturation (IVM) for 19 hours ± 1 hour (GV) or 4 hours ± 30 minutes (MI) according to a maturation time curve determined before the beginning of the present study. Using immunostaining and fluorescence microscopy, we imaged spindle and chromosomal distribution of oocytes that extruded the first polar body after IVM. RESULTS: IVM rates were similar for both groups (53.1% and 50%, respectively, for the PCOS and control groups). Spindle and chromosome organization were observed in 35 and 17 oocytes from the endometriosis and PCOS groups, respectively. In the endometriosis group, 13 were normal MII oocytes (37.2%), 9 abnormal MII (25.7%), 11 normal telophase I (31.4%), and 2 normal telophase II (5.7%). In the PCOS group, 6 oocytes were normal MII (35.3%), 8 abnormal MII (47.1%), and 3 normal telophase I (17.6%). The proportions of normal MII oocytes were similar for the two groups (37.2% and 35.3% in endometriosis and PCOS groups, respectively). CONCLUSIONS: Our preliminary data demonstrate that in vitro maturation rates of immature oocytes obtained from stimulated cycles are similar in non-obese infertile women with endometriosis and with PCOS. In vitro matured oocytes from endometriotic patients have a higher percentage of TI when compared to PCOS patients. Our preliminary results also suggest that the incidence of meiotic anomalies, characterized by spindle rupture and/or chromosome misalignment, is similar in in vitro matured oocytes from non-obese PCOS and endometriotic patients. Both results will be better evaluated by increasing the present patient series.