Overall, 10 - 15% of couples seek specialist help once in their lives when a spontaneous pregnancy does not occur. These couples are defined subfertile when there is at least one year of unprotected intercourse without conceiving. Subfertility can have different causes. A basic fertility work-up focuses on the reproductive system of the couple. After this basic fertility work-up the subfertility remains unexplained in 16-24% of the couples. The investigators hypothesize that cardio-metabolic and hemodynamic abnormalities reducing cardiovascular reserves relate to circulatory redistribution at the expense of uterine perfusion and with it women's fertility. This could especially be important in the subgroups with an unexplained subfertility and a decreased ovarian reserve. For all possible assessed abnormalities, proven effective treatments are available such as primarily life style corrective actions. Furthermore these interventions could lead to better results in fertility treatment, better obstetric outcome and reduced lifelong health risks.