Effects of Hormonal Contraceptives on Liver Proteins and Coagulation Factors: A Comparison of a Contraceptive Vaginal Ring and an Oral Contraceptive

The purpose of this 3-month (cycle) study was to evaluate the effects of hormonal contraceptives containing a progestin and an estrogen on liver proteins and coagulation factors that are sensitive to estrogen. In this study, a contraceptive vaginal ring containing Nestorone® (a progestin with no androgenic properties) and ethinyl estradiol was compared to an oral contraceptive containing levonorgestrel (an androgenic progestin) and ethinyl estradiol.

Inclusion criteria

• Healthy women, aged 18-34 years, who did not wish to become pregnant for 3 months (or 5 months if first discontinuing oral contraceptives
• Intact uterus and at least 1 ovary
• Have regular menstrual cycles (28 ± 7 days) or 2 regular cycles after parturition or abortion
• Willing to use condoms while having sexual intercourse during the 3 month study (or 5 months if discontinuing oral contraceptives), or
• Willing to continue use of a specified non-hormonal method of birth control including permanent sterilization, non-hormone-containing IUD, male condoms, or abstinence during the study or to use condoms if discontinuing one of these methods
• Willing and able to comply with the protocol
• Willing and able to sign informed consent prior to entry into the study and prior to discontinuing another method of contraception
• Easy venous access

Exclusion criteria

• Pregnancy
• Known hypersensitivity to estrogens or progestins
• Known hypersensitivity to silicone rubber
• Undiagnosed vaginal discharge or vaginal lesions or abnormalities
• Smoking status: >15 cigarettes per day
• Breastfeeding
• Current or past thrombophlebitis or thromboembolic disorders
• Family history of venous thrombosis or embolism (1st degree relatives <55 years of age)
• Known history of Factor V Leiden or positive screening test for APC-resistance
• Current or past cerebrovascular or coronary artery disease
• Carcinoma (hormone-dependent tumor; past history of any carcinoma not in remission for >5 years)
• Medically diagnosed severe depression
• Headaches with focal neurological symptoms
• Undiagnosed abnormal genital bleeding
• History of cholestatic jaundice of pregnancy or jaundice with prior steroid use
• Benign or malignant liver tumors; active liver disease
• Diastolic/systolic BP ≥90/140 mmHg after 5 min. rest
• Known or suspected alcoholism (>2 drinks/day)or drug abuse
• Positive for hepatitis B & C and/or HIV 1 or 2, abnormal screening CBC, serum chemistry values (including fasting, total cholesterol and triglycerides), abnormal Pap smear, abnormal findings on dipstick urinalysis, or an abnormal electrocardiogram (ECG)
• Participation in a clinical trial within last 3 months or more than 1 trial in the last year
• BMI (kg/m2) >28
• Use of injectable contraceptives in last 6 months (e.g. cyclofem or DMPA)
• Unwilling to stop oral contraceptives for 2 months prior to study initiation
• Use of implanted hormonal contraceptives, including Mirena or Implanon, in last 2 years
• Not living in the catchment area of the clinic*Severe cystoceles or rectoceles