AGE-RELATED-CHANGES IN THE FEMALE REPRODUCTIVE-CYCLE

Objective To investigate the effect of age on the control of the repro ductive cycle in regularly menstruating women. Design In this prospect ive study all women were seen regularly during both the follicular and luteal phases. Ultrasound scanning was used to confirm ovulation and measurements were taken to assess follicular development and endometri al thickness. Serum gonadotrophin levels on day 4 of the cycle, the ma ximum periovulatory oestradiol and progesterone on the seventh day aft er ovulation were measured and compared in different age groups. Subje cts and Setting Fifty-six healthy, regularly menstruating women were r ecruited from Volunteers amongst staff of the University Hospital of S outh Manchester. Results Ovulation occurred later in the cycle for old er women, with mean follicular phase length increasing from 13.9 days (in group 21-25 years) to 15.9 days (in group 37-45 years (P < 0.05). The mean of the maximum follicular diameter prior to rupture was signi ficantly smaller in the older women: 16.7 mm in the 37 to 45 years old group compared with 19.6 mm, 21.6 mm and 21.3 mm in the 21 to 25, 26 to 31 and 32 to 36 years old age groups, respectively (P < 0.001). The maximum thickness of the endometrium in the luteal phase was greatest for older women: 15.9 mm in the age group 37 to 45 years compared wit h 12.1 mm in the age group 21 to 25 years (P < 0.001). Serum gonadotro phin concentrations during menses were higher with increased age; mean follicle stimulating hormone was 4.8 iu/l in the age group 21 to 25 y ears, and 8.5 iu/l in the age group 37 to 45 years (P < 0.001). Mean l uteinising hormone was 4.5 iu/l in age group 21 to 25 years and 7.21 i u/l in age group 37 to 45 years (P < 0.001). Mean ovarian steroid conc entrations were no different. Conclusions These data illustrate signif icant age related differences in the pituitary-ovarian axis and endome trial thickness. This has implications for the management of older wom en in assisted reproduction and fertility control programmes.