no participants were recruited,study stopped

To evaluate the influence of circadian rhythm on progesterone levels during follicular phase of natural cycle and during follicular phase of controlled ovarian stimulation during IVF.

The primary aim of this study is to determine the circadian rhythm of progesterone in a stimulated cycle. Sample size calculations show that the study needs to recruit 10 women to show any significant differences in progesterone secreted in the morning at 8 am compared to that secreted in the evening at 8 pm. We have increased the number of participants to 12 in order to compensate for any possible drop outs. The hormones FSH, LH, Progesterone and Estradiol will be measured at days 2/3, 8, 10 and 12 of a normal and stimulated cycle so that each patient serves as her own control.

This study will provide the basis to establish the optimal blood sampling time for progesterone measurement and to more accurately determine the cut-off level for progesterone for favourable pregnancy outcomes in ART.

Inclusion Criteria:

• Indication for IVF / ICSI - treatment
• Age ≥ 18 years and ≤ 35 years
• Ovarian reserve parameters in the adequate age - range, determined by Anti-Mullerian-Hormone (AMH) and Antral Follicle Count (AFC)(16)
• Able to understand the aim of the study and to provide consent
• Regular cycle (25-35 days)

Exclusion Criteria:

• Diagnosis of polycystic ovarian syndrome (PCOS) Rotterdam criteria
• Endometriosis stage 3 or 4 AFS
• Treatment with GnRH-analogues during the previous 6 months
• Intake of oral contraceptive pill (OCP) or any hormonal treatment during the last 3 months

Patients who have to undergo IVF due to primary or secondary infertility.