Treatment strategies in assisted reproduction for women of advanced maternal age

In a spontaneous menstrual cycle, during the follicular phase, only one follicle out of a cohort of 10-20 usually completes maturation and ovulates to release a mature oocyte. The aim of ovarian stimulation in assisted reproductive technology (ART) protocols is to overcome the selection of a dominant follicle and to allow the growth of a cohort of follicles. This strategy leads to an increase in the number of oocytes and hence embryos available for transfer, thereby increasing the chance of transferring up to three viable embryos. However, the chance of pregnancy and also live birth begins to dramatically decline after the age of 35, and successful treatment for these patients continues to be a major challenge in ART programs. Preimplantation genetic screening studies over the last decade have identified a dramatic increase in the rate of aneuploidy as a major contributor to the reduction in embryo viability in older patients. It has also been demonstrated that women of advanced maternal age may have oocytes that are compromised by a significant reduction in the amount of mitochondrial DNA in their cytoplasm. The strategies outlined in this review may provide a means of augmenting follicular recruitment and cytoplasmic integrity by utilizing pharmacogenomics and manipulating endocrinology to improve the prognosis for these women. Recent studies indicate that androgen supplementation may be one area to explore further. The availability of recombinant human leutinizing hormone (rhLH) has made it possible to investigate the role of LH in the endocrinology of follicular recruitment: it appears that a defect in the balance of LH/ follicle-stimulating hormone (FSH) might be involved in the subtle age-related decline in follicular recruitment, and patients of older reproductive age undergoing ART might benefit from the addition of LH and/or hGH. Further studies are required to investigate the physiological mechanisms behind this observation and to assess the possible effect of LH and/or hGH supplementation on the age-related decline in pregnancy rate.