Transvaginal Ultrasonographic Imaging of Ectopic Pregnancy

Abstract

EDITORIAL COMMENT: This case report makes the useful point that transvaginal ultrasonography is superior to transabdominal for the diagnmis of ectopic pregnancy, and d m not require the patient's bladder to be distended. It also reminds us that ectopic pregnancy can occur following tubal ligation. Readers will probablyagree with the editor that in thk patient, the clinical features warranted immediate laparotomy even had the ultrasonographic evidence not been available.Ectopic pregnancy is a common gynaecological emergency associated with significant maternal mortality and morbidity. Despite a high index of suspicion, a definitive preoperative diagnosis is often very difficult to make. Apart from other investigational aids, ultrasonography has been used to assist in the management of suspected cases of ectopic pregnancy (1). We report a case of tubal pregnancy diagnosed readily by transvaginal ultrasonography. CASE REPORTA 35-year-old gravida 4, para 3 Chinese housewife was admitted with colicky lower abdominal pain for 2 days. She had 8 weeks of amenorrhoea and a positive urinary pregnancy test 6 days earlier. There was no vaginal bleeding. She gave a past history of postpartum sterilization by tubal ligation after her last delivery 12 months ago.Her general condition was satisfactory on admission. She was apyrexial and not clinically anaemic. However, there was marked tenderness over the lower abdomen with guarding and rebound tenderness. Pelvic examination revealed cervical excitation pain and generalized tenderness making assessment of the uterus and the adnexa very difficult.The haemoglobin value was 10.0g/dl and the white cell count was 17.4 x 10/1. Transvaginal ultrasonography using a 5-MHz convex probe (Model UST-938P-5, Aloka Co., Ltd., Japan) revealed a gestational sac containing a live fetus adjacent to the empty uterus ( figure 1). The crown-rump length measurement of 1.7cm was consistent with 8 weeks' gestation and fetal movements could be clearly observed.Laparotomy was performed immediately and a right tub& pregnancy was confirmed with one Iitre of blood in the peritoneal cavity. 1.Lecturer. Medical Officer.The uterus, the left Fallopian tube apart from evidence of previous sterilization, and both ovaries were all normal. Right salpingectomy was carried out and haemostasis was satisfactory.Postoperative haemoglobin value was 8.6g/dl and, after transfusion of one litre of blood, it was restored to 11.6 g/dl. Her recovery from the operation was otherwise uneventful.Histological examination of the right Fallopian tube, measuring 6cm from the fimbrial end, showed a dilated ampullary portion containing a small embryo within a gestational sac. The embryo had a crownrump length of 1.3cm and chorionic villi as well as blood clots were present within the dilated lumen (figure 2). DISCUSSIONIn this patient, a tubal pregnancy occurred 1 year after postpartum sterilization. It has been emphasized that of the patients who conceived after tubal ligation or application of spring-loaded clips, approximately 15% ha...