Page 17 - Fertility in Women with Rheumatoid Arthritis Vruchtbaarheid van vrouwen met reumatoïde artritis

General introduction
ends approximately 10 years before menopause occurs.31 It is therefore that the age at 1 which fertility ends has a similar broad range as the occurrence of menopause.
Figure 1 – Wallace-Kelsey model describing the nongrowing follicle populations (NGF) from conception to menopause, and the 95% con dence intervals and 95% prediction limits for the model. The predicted average age at menopause with this model is 49.6 years (95%PI 38.7–60.0 years). (Duplicated with permission from the author, source: Wallace, PLoS One 2010.35
Anti-Müllerian hormone as a measure of ovarian function
The size of the ovarian follicle pool can be estimated by measuring serum levels of anti-Müllerian hormone (AMH). AMH is a member of the transforming growth factor β family, and is well known for its role in the regression of the Müllerian ducts in the male foetus.36 In women, AMH is speci cally produced by the granulosa cells of the small growing ovarian follicles.33,37 AMH levels are rst detectable in the female foetus at 36 weeks of gestation, when ovarian primordial follicles start developing into primary follicles.38 AMH expression is highest in secondary, preantral and small antral follicles (≤4 mm), until it disappears in larger antral follicles (4-8 mm).37
AMH has a function in the regulation of follicle recruitment. In AMH knock-out mice, there is an increased rate of follicle recruitment, which leads to premature depletion of the ovarian follicle pool and consequently anovulation.39 Furthermore, AMH affects the sensitivity of follicles to follicle stimulating hormone (FSH) from the pituitary gland. In the absence of AMH, the individual threshold of a follicle for FSH seems to be lower.39
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