Abstract:
Our purpose was to determine if blood samplings in the mornings after night shifts should be avoided for measuring the basal serum prolactin levels in women working at night and with regular menses; 20 nurses with regular menses, all working only at night shifts, were enrolled in this study. Serum prolactin levels of the subjects were determined twice, first in the morning after a typical night's sleep, with no intercourse within the previous 24 hours, second, in the morning after a typical night shift. All measurements of serum prolactin levels were performed in the follicular phase of the menstrual cycle. Prolactin levels in the mornings after typical night's sleeps and in the mornings after typical night shifts were not significantly different. Prolactin level in the morning after a night shift of a woman with regular menses may represent basal prolactin level of that woman.