[Fetal transverse position caused by giant leiomyoma in the lower segment of the uterus. A case report].

A 20-year-old primigravida presented at 39 weeks' gestation with the fetus lying in the transverse position. Ultrasound examination indicated an anterior placenta praevia grade II-III. During a vertical lower uterine segment caesarean section, a giant intramural leiomyoma of approximately 25 X 25 cm was found. The uterine incision was extended into the upper segment and a healthy male fetus of 2 568 g delivered. The placenta was situated anteriorly but did not extend into the lower uterine segment. A myomectomy had to be performed to enable closure of the uterine incision. The association of a transverse lie with anterior implantation of the placenta may result in a false ultrasound diagnosis because the lower anterior portion of the uterine wall and the attached portion of the placenta simulate a placenta praevia. In our case, an unsuspected leiomyoma in the lower segment contributed to this. Furthermore, this case illustrates the advantage of using a lower uterine segment vertical incision when performing a caesarean section for transverse lie. The incision can then readily be extended into the upper uterine segment when necessary.