Background: To determine the effects of age and the serum anti-Müllerian hormone (AMH) level on in vitro fertilization (IVF) outcomes, especially among young women with low serum AMH levels and older women with high AMH levels.
Methods: This study was a cohort study in which a total of 9431 women aged 20-51 years who were undergoing their first IVF cycles were recruited. Ovarian response parameters included the number of retrieved oocytes, the number of 2 pronuclear zygotes (2PN), and the frequency of good-quality embryos (GQE). Pregnancy outcomes included the clinical pregnancy rate (CPR), live birth rate (LBR), miscarriage rate (MR), and cumulative CPR and LBR (CCPR and CLBR).
Results: Among women under 35 years of age, the ovarian response, CPR, CCPR, LBR and CLBR (p < 0.01) were significantly lower in the low-AMH group than in the average-AMH and high-AMH groups. In women above 35 years of age, the ovarian response, CPR, CCPR and CLBR (p < 0.01) were significantly higher in the average-AMH and low-AMH groups. The LBR in the older high-AMH group was significantly higher (37.45% vs 20.34%, p < 0.01) than that in the older low-AMH group, but there was no difference (37.45% vs 32.46%, p = 0.11) compared with the older average-AMH group. When there was a discrepancy between age and the AMH level, the young low-AMH group showed a poorer ovarian response but a better CPR (58.01% vs 49.44%, p < 0.01) and LBR (48.52% vs 37.45%, p < 0.01) than the older high-AMH group. However, the CCPR (65.37% vs 66.11%, p = 0.75) and CLBR (56.35% vs 52.89%, p = 0.15) between the two groups were comparable. The conservative CLBR in the two discrepancy groups increased until the third embryo transfer and reached a plateau thereafter.
Conclusion(s): Even with a relatively low AMH level, young women still had better pregnancy outcomes following IVF than older women. However, increasing the AMH level improves the cumulative outcomes of the older group to a comparable level through a notable and superior ovarian response.
Keywords: AMH; Advanced age; IVF; Live birth; Ovarian reserve.