Effects of norgestimate in combination with ethinyl estradiol on cervical mucus

The antifertility effect of norgestimate (Ng) 0.125 mg in combination with ethinyl estradiol (EE) 0.035 mg on cervical mucus of 5 apparently normal and ovulatory volunteer women was studied for 2 cycles: a control cycle followed by a study cycle in which the medication was given. Throughout both cycles, basal body temperature, cervical mucus properties, sperm penetration in cervical mucus and karyopyknotic index of vaginal cells were evaluated. Disappearance of cyclicity of these parameters in the study cycle as well as monophasic basal body temperature were suggestive of inhibition of ovulation caused by the combination pill. Deterioration of cervical mucus properties throughout the study cycle and inhibition of sperm penetration may be a reflection of anovulation. However, a direct antifertility effect of Ng on cervical mucus cannot be excluded.