The diagnosis of ectopic pregnancy rests on the results of plasma beta-HCG hormone assays and on those of ultrasonography. If the plasma level of beta-HCG is lower than 10 m IU/ml, the woman is not pregnant; if it is higher than 10 IU/ml, ectopic pregnancy is excluded when ultrasounds show a gestation sac within the uterine cavity from the 5th week of amenorrhoea onward. The diagnosis of ectopic pregnancy is certain when ultrasounds show a gestation sac outside the uterine cavity; it is highly probable when they show an inhomogeneous masson the side of the uterus or a collection of blood in Douglas' pouch.
