A RANDOMIZED TRIAL OF INVITRO FERTILIZATION VERSUS CONVENTIONAL TREATMENT FOR INFERTILITY

Objective: To evaluate the effectiveness of IVF in couples with infert ility. Design: Two hundred forty-five consecutive couples with inferti lity were randomized to receive one cycle of IVF treatment (experiment al group) or to wait for a period of 6 months before receiving IVF tre atment, during which time other infertility treatments could have been undertaken (control group). Setting: Patients were referred to the Fe rtility Clinic at Chedoke-McMaster Hospitals, a university associated institution in Hamilton, Ontario, Canada, in which IVF has been offere d to couples since 1984. Patients: Couples with infertility (mean dura tion of 65 months) not corrected. by conventional treatment. They came from all socioeconomic classes, and the costs of IVF treatment, excep t medication, were covered by the Ontario Health Insurance Plan. Main Outcome Measure: Pregnancy was confirmed by ultrasound documentation o f a gestational sac or histologic examination of tissue. Outcomes incl uded livebirth, spontaneous abortion, and ectopic pregnancy. The overa ll pregnancy rate (PR) and the interval-to-pregnancy duration were com pared in each group. Results: Univariate analysis demonstrated a signi ficant beneficial effect of IVF treatment in patients with bilateral s evere tubal disease. Although in other diagnostic categories the crude and cumulative PRs in the experimental group were higher than in the control group, the differences did not reach statistical significance. Among the early IVF group, those with endometriosis had significantly more pregnancies when compared with other diagnostic categories. Alth ough IVF increases the likelihood of pregnancy by 40% with severe tuba l disease, the overall 31% increase associated with IVF was not statis tically significant. Conclusions: There was a significant difference i n favor of treatment in patients with severe bilateral tubal disease. For couples with other causes of infertility, the confidence limits ar ound the treatment effect included unity. To reject the null hypothesi s of no treatment effect, a larger sample size or a meta-analysis to c ombine the results of similar trials is required.