PIP: The authors discuss the problem of prematurity in primiparas who have had previous spontaneous and induced abortions. A study was carried out during the period 1973-81 at the Obstetric Clinic of the 3rd Unified Hospital in the city of Sofia. 303 primiparas were examined who had been admitted to the hospital with premature labor. 852 (5.99%) out of 14,225 deliveries were premature during the period studied; 5662 women (40%) were primiparas, and 8.58% (486) delivered prematurely. The frequency of delivery in general was 5-7%. The authors infer that abortion has an unfavorable influence on subsequent pregnancies in primiparas. The induced abortions more rarely cause premature deliveries than do spontaneous abortions. Perinatal mortality, although higher in primiparas with preceding abortions, is less dependent on the type of abortion experienced. (author's modified)