Stress prolactin and infertility. (Letter)

Dr. Haydn Smith suggests (January 6 1979 p. 62) the possibility of a prolonged period of stress leading "to a sustained increase of the mean prolactin concentration sufficient to cause infertility" link between emotional stress and some forms of infertility has long been recognized. We have studied 30 infertile couples with none of the usual barriers to fertility nor any abnormality in pituitary tomography or hormonal profiles including serum prolactin. The patients were randomly assigned to placebo or bromocriptine (2.5 mg twice daily) for 6 months. Biochemical variables were monitored at the beginning of the study and 3 and 6 months thereafter and a final blood sample was taken 2 months after the end of the 6-month trial. In 11 of the patients a raised serum prolactin (18-40 ng/ml) was found at least once. We consider this range to be compatible with "stress hyperprolactinaemia." Of these 11 patients only 1 became pregnant compared with 7 (37%) of those who with normal serum prolactin levels throughout (figures for both bromocriptine and placebo groups are presented in tabular form). Such differences suggest that in some women an intermittent hyperprolactinemia might indeed be a contributory factor in infertility. Our investigations are continuing on this premise.