Overview
The study design is an observational cohort study. Level of serum P4 will be collected on day OR+4 as well as on the day of embryo transfer (ET) either day OR+3 or OR+5.
Eligibility
Inclusion Criteria:
- Signed informed consent
- BMI <35kg/m2
Exclusion Criteria:
- No fresh embryo transfer
- Prior participation in the study