Serum levels of oestradiol-15 beta and luteinizing hormone related to follicular growth as monitored by ultrasound in women with normal menstrual cycles.

Serum levels of oestradiol-15 beta (Oe2), luteinizing hormone (LH) and progesterone (P) in 20 healthy women were correlated to the size of the ripening follicle during the follicular phase of normal menstrual cycles. Growing follicles were measured by ultrasound using the full bladder technique. In each individual case a good correlation (r = 0.88) between the Oe2 values and the size of the maturing follicle was found. However, since all women examined ovulated at a different Graafian follicle diameter (range 17 to 26 mm), the corresponding Oe2 values showed quite a large variation (range 0.78 to 2.5 nmol/l). The cervical score correlated to follicular maturation up to a follicle size of 19 mm (maximal cervical reaction). From there on no further improvement of the cervical parameters could be observed. We conclude that ultrasound monitoring of follicular growth can be a useful addition to the Oe2 and P measurements in the clinical management of the infertile woman. Bifollicular maturation can be diagnosed early, when the endocrinological data are combined with follicle size. Moreover, a correlation can be made between follicular growth and oestradiol production in the individual cycle.