Carbon dioxide laser conisation is a very reliable surgical technique for cervical intraepithelial dysplasia. As cervical morphology and function are better preserved than with other techniques, obstetrical morbidity should be lower in the often young and pauciparous women who undergo this procedure. In our study comparing the course of 71 pregnancies (55 children) in 54 operated women with that of 82 pregnancies (59 children) in these same women before conisation, the rates for complications at the beginning of pregnancy were similar (respectively, 14.1% and 13.4%, early spontaneous abortions; 2.8% and 2.4%, extrauterine pregnancies; and no late spontaneous abortions). The increased risks of premature delivery (13.2% vs. 8.5%), chorioamnionitis (1.9% vs. O%), premature rupture of membranes (1.9% vs. 0%) and prematurity (11.3% vs. 1.7%) were not statistically significant. Only the percentage of natural term births was significantly reduced (73.6% vs. 90%; P = 0.025), but this difference was no longer apparent after correction for the prevalence of associated obstetrical pathologies and prematurity and/or cesarean factors which was significantly greater for the 53 pregnancies that developed after carbon dioxide laser conisation.