AGE-RELATED DECLINE IN FEMALE FERTILITY IS NOT DUE TO DIMINISHED CAPACITY OF THE UTERUS TO SUSTAIN EMBRYO IMPLANTATION

Objective: To evaluate the contribution of the uterus to age-related r eproductive failure in women. Patients: Thirty-eight ovum donors (30.2 +/- 4.9 years [mean +/- SD]) donating oocytes throughout 102 ovum don ations. Fifty-one cycles were documented in ''younger'' recipients (35 .8 +/- 3.1 years) and 51 in ''older'' recipients (44.0 +/- 3.1 years). The study was prospectively designed; same-cohort oocytes obtained fr om one young donor during a specific cycle were evenly distributed bet ween ''young'' and ''old'' ovum recipients. Use of oocytes from a sing le source and a unique ovulatory cohort provides strict control over o ocyte quality. Uterine age is varied by design, according to the age o f the recipient at the time of ET. The role of the aging uterus in the decline of female fertility can be thus isolated and scrutinized. Res ults: No significant (NS) difference in the number of ova received (7. 9 +/- 3.4 versus 7.0 +/- 3.5) ova fertilized (4.4 +/- 1.5 versus 4.5 /- 2.3), or embryos transferred (4.1 +/- 1.5 versus 4.1 +/- 1.6) was o bserved between the <40 and greater than or equal to 40 recipient age groups. A total of 23 pregnancies occurred among the 102 ETs (22.6%). Eleven clinical pregnancies (21.6%) resulting in 10 deliveries were ob served in the <40 recipient age group, and 12 clinical pregnancies (23 .5%) leading to 10 deliveries occurred in the greater than or equal to 40 recipient age group (NS). The pregnancy loss rates were 9.1% (1 of 11) and 16.7% (2 of 12) for the two recipient age groups, respectivel y, (NS). Conclusion: The capacity to conceive and to gestate a concept ion to term when oocyte quality is controlled appears to be independen t of uterine aging through the fifth decade of life.