Synthetic vs Natural Estrogen in Combined Oral Contraception

Synthetic vs Natural Estrogen in Combined Oral Contraception- Effect on Insulin Sensitivity, Coagulation, Inflammation and Endometrium - a Comparison With a Progestin-only Preparation.

The main objective of the study is to compare the metabolic effects of natural estradiol and synthetic ethinylestradiol used in combined oral contraception in healthy women. A progestin-only preparation will be used in comparison. The main goal is to study the effects on glucose metabolism, coagulation and a markers of chronic inflammation (such as hs-CRP). Our hypothesis is that the natural estradiol preparation will influence blood glucose levels, markers of coagulation and chronic inflammation less than the ethinylestradiol preparation. The progestin-only preparation will not effect these parameters.

Inclusion Criteria:

• BMI 19-24.9, regular menstrual cycles (21-35 days), a minimum of 2 months without any hormonal contraceptives, no contraindications for use of hormonal contraception

Exclusion Criteria:

• Polycystic ovaries, hypertension, smoking, alcohol abuse, pregnancy, lactation, abnormal result in pre-screening 2h oral glucose tolerance test, regular medications