AbstractsThe authors of this report present a series of 21 women with unicornuate uteri, giving the outcomes of their pregnancies and the results of therapy. The women were followed from 1975 to 1984. The malformation was identified and classified according to the Buttram and Gibbons criteria. In this classification, the unicornuate uterus is subdivided into four subclasses, according to the presence or absence of a rudimentary horn and whether it is cavitary and/or communicating. For precise classification of the patients, hysterosalpingography and laparoscopy or laparotomy were performed on each woman, with the following results: one patient in subclass A1a(with cavitary communicating rudimentary horn), six in subclass A1b(with cavitary noncommunicating rudimentary horn), seven in subclass A2(with noncavitary rudimentary horn), and seven in subclass B (without rudimentary horn). The contralateral adnexum was absent in three cases, all of which were in subclass B.Intravenous urography was performed on 16 patients, and an associated unilateral renal malformation was seen in seven (43.7 per cent): renal ptosis in two cases, renal agenesis in three, double renal pelvis in one, and horseshoe kidney in one.Two patients of subclass A1awere excluded from the study because of their ages (14 and 15 years, respectively, at the time of diagnosis). The obstetrical histories of the other 19 patients were evaluated retrospectively, and the evolution of fertility was followed prospectively for 2 to 10 years.Six patients had primary infertility of 2 to 16 years' duration, and 13 women had had 25 pregnancies, one of them in a rudimentary horn (4 per cent). Abortions occurred in 16 instances (64 per cent), premature live births occurred in three (12 per cent), and term deliveries occurred in five (20 per cent), with a live birth rate of 32 per cent.Endometriosis was detected in three women (one at American Fertility Society (AFS) stage I and two at AFS stage II) and ovulation defects were detected in two others. Danazol was given to the women with endometriosis, and clomiphene citrate was given to those with ovulation disorders. Rudimentary horns were removed from five patients. In one of these, the operation was indicated because of a pregnancy in the horn, and in the other four, the operation was elective. Pregnancy was achieved in these four women, resulting in term live infants in three cases and an abortion in one (Table 1).Delivery was by cesarean section in nine of the 11 pregnancies (81.8 per cent) because of breech presentation in six, intrauterine growth retardation in two, and a previous cesarean birth in one.