Endometrial Effects of Lipiodol

A single‐centre, cross‐over, open‐label trial will be performed. Healthy volunteers, fulfilling the inclusion/exclusion criteria, will be asked to do blood samples and ultrasounds for the detection of the LH (luteinizing hormone) surge in a natural cycle. The intervention group will undergo endometrial flushing with Lipiodol between day 6 and 8 of the cycle, while the control group between day 6 and 8 of the cycle will have a mock catheter introduction without any Lipiodol flush. An endometrial biopsy will be performed 7 days after the LH peak in all the participants. Furthermore, all the participants will undergo one cycle with flushing and one cycle with introduction of a mock catheter but without flushing with any medication. The wash‐out period between the 2 biopsies will be 3 months.