Dados do Trabalho

Title

Impacts of female age and life habits, associated with male factor, on the development of oocyte and embryos

Objective

Several factors can alter the quantity and quality of oocytes and also of embryos produced in Assisted Human Reproduction (AHR) treatments, with emphasis on age and obesity in women, as well as the presence of infertility in men. In this sense, the objective of this study was to analyze the existing relationships between the oocyte and embryonic development of patients submitted to AHR treatment, with age and female life habits, and male factor infertility.

Methods

Data were collected from patients treated at the Assisted Reproduction Center of the Januário Cicco Maternity School (CRA/MEJC), Natal/RN, Brazil (Ethics committee of Federal University of Rio Grande do Norte, approval no 3.490.438), between 2013 and 2018, and who consented in the access of their medical records (n=280). The criteria for inclusion in this study were refined to participants with infertility due to anatomical factors, advanced age, obesity, and infertility of the couple due to male factors, reducing the final sample population of this study to 144 participants. To analyze the existence of a correlation between maternal age and BMI with embryonic development, cases in which there was a male factor as the etiology of infertility were excluded from the sample group, to reduce the influence of other factors on the quality of the embryo. Therefore, for these correlations, only the embryos of patients with infertility due to anatomical factors and no male factor were selected (n=94). Data analysis was performed using the SPSS software, and depending on the nature of the variables, simple linear regressions were performed with Spearman's coefficient, multiple linear regressions and means comparison test using the Mann-Whitney U test (p<0.05 significance), and descriptive statistical analysis to determine the socioeconomic profile of the sample group.

Results

Patients eligible for this study were 36 years old on average when they started their treatment, had completed high school (51%), were brown (74%) and overweight (54%). In 62% of cases, infertility was primary. A positive correlation was found between the patient's age and the number of oocytes collected, the number of grade 3 oocytes and the number of discarded oocytes. By correlating female age and embryonic development, a reduction in the symmetry of blastomeres according to embryonic development was observed in D2 and D3, in relation to age, as well as lower rates of cleavage and blastocysts. The increase in BMI in women was associated with a reduction in cleavage rates, with an increase in the amount of immature and discarded oocytes during treatment. By verifying whether the age and BMI of the patients, together, can predict the parameters of oocyte and embryonic quality, only the BMI proved to be statistically relevant. Among the male factors found in the partners of eligible patients for the present study, oligoasthenozoospermia stood out as an isolated factor, and varicocele associated with teratooligozoospermia as a combined factor. By comparing the parameters indicative of embryonic quality between the group with male factor infertility and the group without male factor, it was possible to verify that the group without male infertility had a greater number of embryos with symmetrical blastomeres and blastocysts. Regarding treatment success, it was found that there is an association between the presence of male factor and lower positive results for the betaHCG test.

Conclusion

The results of this study are in line with literature data that suggest that a woman's age and lifestyle can negatively affect female fertility, compromising oocyte and embryonic development. When male factor infertility is present, embryonic development is affected, reflecting a smaller number of embryos that reach the blastocyst stage and, consequently, lower levels of positive beta-HCG.

Keywords

Infertility; Body mass index; Male infertility; Embryo quality.