A COMPOSITE PICTURE OF THE NORMAL MENSTRUAL CYCLE

16 normal menstruating Finnish women were evaluated to determine the plasma levels of follicle stimulating hormone (FSH) luteinizing hormone (LH) estradiol and progesterone to correlate these data with changes recorded in target organs (vaginal cytology basal body temperature - (BBT) - spinnbarkeit and ferning of the cervical mucus and endometrial biopsy) and to determine the clinical usefulness of the various determinations. Daily blood samples were taken during 1 cycle. BBT was recorded daily. The amount spinnbarkeit and ferning of the cervical mucus were measured and the karyopyknotic index was used for estimating the vaginal cytology. An endometrial biospy was taken once at the end of the luteal phase. Hormone levels were determined by radioimmunoassay. The estradiol concentration began to rise 8 days before the LH peak and reached its maximum 1 day before. The LH peak was seen in all cycles. FSH was absent in 1 cycle. Progesterone started to rise on the day before LH peak and reached its maximum 5-10 days after the LH peak. Amount spinnbarkeit and ferning of the cervical mucus correlated well with the rise of the estradiol concentration. BBT was uniformly biphasic. There was a poor correlation between hormonal changes and karyopyknotic index. A secretory endometrium was present in every biopsy. It is concluded that the cervical mucus seems to be a good indicator of the rise of the estrogen level and the rise in BBT a sign of elevated progesterone concentrations.