In this study, the hypothesis that embryo development during routine IVF procedures is determined by the pre-ovulatory follicular fluid composition was tested. Follicular fluid from women with obesity ('obese') and a 'positive' or 'negative' IVF outcome was added during the in-vitro maturation of bovine oocytes. 'Negative' and 'obese' follicular fluid reduced bovine embryo development, compared with laboratory control embryo development (P < 0.05 or P < 0.1). The addition of follicular fluid also altered bovine blastocyst gene expression. Furthermore, LDHA and PPARGC1B gene expression differed between follicular fluid groups. Data suggest that pre-ovulatory follicular fluid can potentially affect oocyte developmental competence and embryo quality. Furthermore, the bovine model may be used as a screening tool.

Endogenous and exogenous factors can severely affect the integrity of genetic information by inducing DNA damage and impairing genome stability. The extent to which men with and without subfertility are exposed to several adverse lifestyle factors and the impact on sperm DNA fragmentation (SDF), sperm chromatin maturity (condensation and decondensation), stability (hypo- and hypercondensation) and sperm aneuploidy are assessed in this study. Standardized assays employing flow cytometry were used to detect genome instability in 556 samples. Semen parameters deteriorated with age, BMI, increased physical activity and smoking. Age and BMI were associated with increased SDF. Increased BMI was associated with increased hypocondensed chromatin and decreased decondensed chromatin. Increase in age also caused an increase in sex chromosome aneuploidy in sperms. Surprisingly, alcohol abuse reduced chromatin hypercondensation and drug abuse reduced SDF. Although genome instability was more pronounced in the subfertile population as compared to the fertile group, the proportion of men with at least one lifestyle risk factor was the same in both the fertile and subfertile groups. While one in three benefited from nutritional supplementation, one in five showed an increase in SDF after supplementation. Whilst the message of ‘no smoking, no alcohol, no drugs, but a healthy diet’ should be offered as good health advice, we are a long way from concluding that nutritional supplementation would be beneficial for male fertility.