Plasma prolactin in relation to menstrual cycle phase, oral contraceptive use, arousal time and smoking habits

The study was designed to investigate if modern low dosage combined oral contraceptives were associated with changes in plasma prolactin levels in healthy nulliparous women aged 19-25. Plasma prolactin was not significantly correlated to oral contraceptive use, nor to smoking habits. Plasma prolactin was, however, significantly negatively correlated to time since awakening. A significant two-way interaction on prolactin was also seen between smoking and present oral contraceptive use. In our material the mean values of plasma prolactin were higher in the follicular phase than in the luteal phase, although not significantly.