[The age as a predictive factor in in vitro fertilization cycles].

PURPOSE: to evaluate the patient's age as an outcome predictor in an in vitro fertilization (IVF) program.

METHODS

transversal study, which has included 302 women with ages varying from 24 to 46 years old, submitted to IVF, from May 2005 to July 2007. The patients were divided in three groups, according to their age: G<or=35 (n=161), G 36-39 (n=89) e G>or=40 (n=52). The number of collected oocytes, the fertilization rates, the number of transferred embryos, the embryonary quality and the pregnancy rate were evaluated. Statistical analysis was realized through Kruskal-Wallis variance analysis and chi(2) test.

RESULTS

in the G<or=35 group, an average of 8.8 oocytes by patient was obtained; in the G 36-49 group, 7.4; and in the G>or=40 group, 1.6. The number of oocytes obtained in G>or=40 group was significantly lower than in the other two groups (p<0.001).The fertilization rate was similar in the three groups, 61.4, 65.8 e 64.6% (p=0.2288), respectively. The percentage of good quality embryos was not statistically different among the three groups either, with rates of 57.4, 63.2 and 56.0% (p=0.2254), respectively. The average number of transferred embryos in each group was 3.1 (G<or=35), 2.8 (G 36-39) and 1.5 (G>or=40), respectively, with statistically significant decrease in the G>or=40 group (p<0.001). Concerning pregnancy rates, the G>or=40 group has presented a rate of 9.6%, a result which is significantly lower (p=0.0330) than the one presented by the G<or=35 and G 36-39 groups (26.1 e 27.0%, respectively), with no significant difference between themselves.

CONCLUSIONS

though the embryonary quality is not different among women from different age groups, the number of collected oocytes, the number of transferred embryos and the pregnancy rate indicate that the women's age is an important predictive factor of success for the techniques of assisted reproduction and should be taken into consideration when this kind of treatment is proposed to women over 40.