No evidence of increased uterine vascular impedance with patient ageing following IVF

A study was conducted to determine if uterine vascular impedance increases with advancing age in women undergoing ovarian stimulation for IVF. A group of 162 women who had undergone conventional IVF and embryo transfer was su bdivided into three subgroups by age: 30-34 years (n = 49), 35-39 years (n = 79) and 40-44 years (n = 34). The pulsatility index (PI) and resistance i ndex (RI) of the right and left uterine arteries were measured at baseline, on the day of oocyte retrieval, and at the mid-luteal phase. There were no differences in the average PI or RI by age at any phase of the cycle. In a ll age groups, the luteal phase values of PI and RI were lower than those o bserved earlier in the cycle. Endometrial thickness was not associated with age. There was no significant correlation between PI, RI and serum oestrad iol and progesterone concentrations at any phase of the cycle. Ovarian resp onse, as measured by average number of oocytes retrieved, decreased signifi cantly with age. Thus, reduced pregnancy rates in older women undergoing ov arian stimulation are more likely to occur because of oocyte quality and qu antity rather than uterine senescence. If future studies determine that the use of ovarian stimulation does decrease implantation rates more in older versus younger women, mechanism other than increased uterine vascular imped ance must be sought.