Objective: To develop a fertility prognosis model for infertile couples.
Design: Prospective follow-up study.
Participants: In the period November 30, 1977 to June 1, 1985, 321 consecutive couples were investigated for infertility at Hvidovre University Hospital. Investigation of the female included detection of ovarian, cervical, and anatomic disorders, whereas in the male semen analysis and sperm penetration test (P-test) were performed. Altogether, 108 couples (34%) conceived, whereas 213 (66%) were observed for an average of 2.3 years without having achieved pregnancy.
Main outcome measure: The Cox regression model was used to predict the time required to conceive based on informations provided by fertility investigations.
Results: Three of 16 prognostic variables (the period of infertility, the female infertility factor, and the P-test) possess significant prognostic information. The period of infertility and the P-test are best scored as continuous variables, whereas the female infertility factor are best categorized in four classes, i.e., normal, ovulation or cervical disorder, anatomic disorder, or a combination of disorders.
Conclusions: The three prognostic variables are combined to form a prognostic index that predicts the fecundability of the individual infertile couple.