Prerupture ultrasound diagnosis of interstitial and rudimentary uterine horn pregnancy in the second trimester. A report of two cases.

Pregnancies in an interstitial and rudimentary uterine horn are rare and often fatal varieties of ectopic gestation. Ruptures tend to occur in the second trimester, resulting in maternal morbidity and mortality. Only a few cases of the ultrasonographic diagnosis of unruptured second-trimester interstitial and rudimentary uterine horn pregnancy have been reported. In two such cases second-trimester ultrasonographic examination revealed an unusual pregnancy location, thin uterine wall, incomplete myometrial layer and empty uterus.