Experimental: Tubal flushing during HSG with oil-based contrast

Tubal flushing during HSG HSG will be performed by a gynaecologist, fertility doctor or nurse according to local protocols. HSG will be performed in the follicular phase of the cycle. Preferably, HSG is performed in the next cycle after randomization, but if this is not feasible the procedure may be postponed up till one month after randomization. After cleaning the vagina and cervix, a vacuum cervix adapter will be applied to the cervix or a Lipiodol resistant balloon catheter or hysterophore will be placed through the cervix. Up to 15ml of Lipiodol Ultra Fluid will be injected into the uterine cavity and its spread directly monitored by fluoroscopy. Six to eight radiographs will be taken and assessed by a gynaecologist or radiologist. The maximum amount of oil-based contrast medium is set at 15ml.

Active_comparator: Tubal flushing HyFoSy

Tubal flushing during HyFoSy will be performed by a gynaecologist, fertility doctor, sonographer or nurse according to local protocols. HyFoSy will be performed in the follicular phase of the cycle. Preferably, HyFosy is performed in the next cycle after randomization, but if this is not feasible the procedure may be postponed up till one month after randomization. During HyFoSy approximately 5-10cc of foam will be introduced through a little cervical balloon-less applicator into the uterine cavity. During infusion of the foam into the uterine cavity, a transvaginal ultrasound will be performed which shows whether the Fallopian tubes are patent. The assessment of the procedure will be done by the one who performed the procedure.