Is the short follicular phase in older
women secondary to advanced or accelerated dominant follicle development?
Klein NA, Harper AJ, Houmard BS, Sluss PM, Soules MR.
Division of Reproductive Endocrinology, Department of Obstetrics and
Gynecology, University of Washington, Seattle, Washington 98105, USA. nklein@u.washington.edu
This study sought to determine whether the shortened follicular phase in
ovulatory older women is secondary to advanced (i.e. earlier) or accelerated
(i.e. more rapid) folliculogenesis. Normal ovulatory women, aged 40-45 yr (n
= 15) and 20-25 yr (n = 13), underwent daily venipuncture and transvaginal
ultrasonography throughout the follicular phase of a spontaneous menstrual
cycle (control cycle) and after pituitary down-regulation with a GnRH
agonist (study cycle). As expected, the older
subjects in the control cycles demonstrated an elevated d 3 FSH and a
shortened follicular phase compared with the younger subjects.
After release from hypothalamic-pituitary-ovarian axis suppression, the
early follicular phase FSH peak occurred earlier (6.8 vs. 9.8 d; P <
0.01) and was of a greater magnitude (12.1 vs. 6.5 mIU/ml; P < 0.01) in
the older subjects. The time from release of suppression until the
subsequent LH surge was also shorter (17.5 vs. 20.8 d; P < 0.01) in the
older group. However, the time from FSH peak to LH surge was similar in the
older and younger groups (10.7 vs. 11.0 d; P = 0.74). Compared with younger
women, older subjects had normal follicular phase levels of estradiol and
inhibin A and lower levels of inhibin B in both control and study cycles. We
conclude that the shortened follicular phase observed in older ovulatory
women is due to earlier dominant follicle selection, independent of hormonal
influences from the preceding luteal phase.
Ist
eine kurze Follikelphase ( = 1. Zyklushälfte) der Nebeneffekt eines
vorzeitigen oder beschleunigten
Wachstums des Leitfollikels?
Wie erwartet zeigte
sich bei den älteren Testpersonen ein erhöhter FSH-Wert an Tag 3 sowie eine
verkürzte
Follikelphase.
Wir schliessen
daraus, dass eine verkürzte Follikelphase, welche bei älteren ovulierenden
Frauen
beobachet wird, an einer früheren Selektion des Leitfollikels liegt - unabhängig von
hormonellen Einflüssen
der vorangegangenen Lutealphase