Ultrasonic scanning in suspected ectopic pregnancy.

A consecutive series of 103 ultrasound examinations for suspected ectopic pregnancy is presented. The positive ultrasound diagnosis of ectopic pregnancy was based on the demonstration of fetal heart activity outside the uterus and was correct in four out of four cases. The exclusion of ectopic pregnancy was correct in 71 out of 72 cases. Among 24 patients with an ultrasound report of possible ectopic pregnancy five patients were confirmed to have an ectopic pregnancy. Three patients were lost to follow-up. An echo-free area centrally in the uterus was seen in four out of nine patients with ectopic pregnancy, and may prove useful as a sign of ectopic pregnancy.