The ReceptIVFity acts as a timing-tool for prediction of optimal pregnancy chances and provides insight into the patient's current (two months after sampling) success rate of an IVF/IVF-ICSI treatment. Benefits of physician decision treatment in case of an unfavorable vaginal profile and a low chance of achieving a pregnancy include reducing unnecessary morbidity and treatment cycles, stress and disappointment, while increasing efficacy of the treatment and lowering the costs needed to achieve a pregnancy. The goal of this prospective, clinical non-invasive randomized controlled study, with an additional observational study arm (for women of non-European origin) in naïve IVF or IVF/ICSI patients is to evaluate the efficiency of Shared Decision Making compared to Physician Decision in terms of 1. the success probability of an IVF cycle, 2. the proportion of women with a successful pregnancy 3. the number of unsuccessful IVF cycles. Randomization component Women of European origin will be randomized 1:1 to either the shared decision group or the physician decision group. All women of European origin may undergo one to three cycles of IVF/IVF-ICSI reimbursed by the health insurance. The follow-up ends after the outcome of the last of these cycles has been determined. The desired outcome of the IVF or IVF/ICSI treatment is a successful pregnancy, i.e., a pregnancy with a heart-beat at 12 weeks of gestation. Observational component Women of non-European origin are invited to take part in an observational component of this study. Without further evaluation of the results of their vaginal microbiome, they will continue with the IVF/IVF-ICSI cycle. Women eligible for participation are naïve patients and the follow-up ends after the outcome of the first IVF/IVF-ICSI cycle has been determined.