Ectopic pregnancy

Ectopic pregnancy remains a significant contributor to maternal mortality and morbidity. Despite the obstetrician's awareness of the problems, ectopic pregnancy in many cases still remains a difficult diagnosis. Over the last 10 to 15 years diagnostic ultrasound has become an established means of supplying additional and occasionally diagnostic information on those patients suspected of having an ectopic pregnancy. In essence diagnostic ultrasound can provide information regarding the presence of an intra-uterine pregnancy, a finding which goes a long way to excluding an extra-uterine pregnancy, and can show that there is no gestation sac within the uterus, a finding which raises the level of suspicion of an ectopic pregnancy. In addition to these primary uses, diagnostic ultrasound can also provide information relating to the presence or absence of both an adnexal mass and free fluid in the pouch of Douglas. All of these features, however, are open to error and their appreciation leads to a more rational approach to the interpretation of the overall ultrasound findings. In using diagnostic ultrasound in at-risk patients, side-room urinary pregnancy tests, and if necessary the more sophisticated radioimmunoassays of beta-subunit hCG, should be used in conjunction. From the authors' own studies it was concluded that an empty uterus with an adnexal mass and/or the presence of free fluid in the pelvis, together with positive biochemistry, was able to give a very high level of diagnostic accuracy for ectopic pregnancy (95 per cent). However, an empty uterus alone in the absence of an adnexal mass or free fluid in the pelvis was not of itself a reliable guide to the presence of an ectopic pregnancy even in the presence of positive biochemistry. The finding of a living fetus outside the uterus was an uncommon event (6 per cent), but if present allows an absolute diagnosis of ectopic pregnancy. Finally a negative serum hCG assay virtually excludes the possibility of an ectopic pregnancy. A scheme involving the use of urine pregnancy testing, serum hCG assays and ultrasound has been proposed for the rational management of patients suspected of having an ectopic pregnancy and whose condition is stable. In all circumstances, however, it is stressed that should the patient's condition so warrant then surgical intervention is mandatory irrespective of the ancillary findings.