Expectations of assisted conception for infertility.

OBJECTIVE

To provide reliable prognostic information for couples seeking assisted conception.

DESIGN

Analysis of four years' practice (1988-91).

SETTING

Private university service linked with NHS reproductive medicine services.

PATIENTS

804 couples with various causes of subfertility, median duration five years, median age of women 34 years.

INTERVENTIONS

1280 completed cycles: 950 in vitro fertilisation, 144 gamete intrafallopian transfer, and 186 intrauterine insemination and superovulation.

MAIN OUTCOME MEASURES

Pregnancy and birth rates per cycle and cumulative pregnancy and take home baby rates per couple.

RESULTS

In women under 40 years and men with normal sperm, whatever the cause of infertility, results with in vitro fertilisation improved steadily reaching a pregnancy rate per cycle of 30% (95% confidence interval 26% to 35%) during 1990-1 and birth rate per cycle of 29% (23% to 35%) in 1990. Pregnancy and birth rates for gamete intrafallopian transfer were 36% (28% to 44%) and 26% (17% to 37%) and for intrauterine insemination 18% (12% to 24%) and 16% (10% to 22%). After six cycles cumulative probability of pregnancy was 82% and cumulative take home baby rate 70%. Considering only in vitro fertilisation and gamete intrafallopian transfer after four cycles the pregnancy rate was 78% (66% to 91%).

CONCLUSIONS

Conception is less likely in women over 40 and men with sperm dysfunction. For other couples the prognosis for a live birth is at least as good as for fertile couples if they persist with treatment.