Convenient numerical procedures for estimating cumulative pregnancy curves

OBJECTIVE: To develop a simple estimation procedure that will always converge on a solution for a two-parameter model of cumulative pregnancy curves. DESIGN: Utilize raw data from a previous study in which estimation of the two-parameter model did not converge on a solution, and re-estimate the model with the new estimation method. PATIENTS, SETTING, TREATMENT: Infertile women with endometriosis treated as outpatients with laser laparoscopy. MAIN OUTCOME MEASURES: Pregnancy and ability of the new computer program to converge on a solution. RESULTS: The new estimation procedure converged on a solution. Over all stages of endometriosis, the cure rate from laser laparoscopy was 56%, and the monthly probability of pregnancy among those cured was 9.7%. CONCLUSIONS: The new estimation procedure, written for a personal computer, is easy to use and will virtually always converge on a solution for the two-parameter model of cumulative pregnancy after infertility treatment.