Objective: To analyse the effect of ageing on female fertility in an in vitro fertilisation programme in Hong Kong.
Design: Retrospective study.
Setting: University teaching hospital, Hong Kong.
Patients: Seven hundred and seventy-one women in whom 1336 cycles of in vitro fertilisation were initiated between 1 January 1986 and 31 December 1995.
Main outcome measures: Patient age and indications for treatment; hormonal response; and the number of cancelled cycles, oocytes retrieved, oocytes fertilised, cleaving embryos, embryos transferred, and clinical pregnancies.
Results: Compared with women aged <or =30 years (n=193), women aged > or =36 years (n=398) had a significantly higher cycle cancellation rate (19.3% versus 10.4%), fewer oocytes retrieved per retrieval cycle (6.6 versus 9.0), fewer oocytes fertilised per retrieval cycle (5.0 versus 7.0), fewer cleaving embryos per retrieval cycle (4.8 versus 6.8), and lower serum oestradiol level (9735 [standard deviation, 5681] pmol/L versus 10 708 [5916] pmol/L) despite a larger amount of human menopausal gonadotrophin having been used (all variables, P<0.01; Chi squared test). The clinical pregnancy rate per initiated cycle (range, 7.5%-13.0%) decreased with advancing age (P<0.01; Chi squared test).
Conclusion: Ageing has a significant deleterious effect on women's reproductive capability. Women should be encouraged to seek early medical advice and treatment for subfertility.