Pregnancy in a non-communication rudimentary uterine horn.

A case of pregnancy in a rudimentary uterine horn is presented. The pregnancy ended in fetal demise at the end of the second trimester. The diagnosis was missed by ultrasonography on two occasions and was made only at laparotomy following failure to initiate uterine contractions. Histologic examination of the myometrium of the rudimentary horn revealed extensive interstitial fibrosis. A high index of suspicion of pregnancy in a rudimentary horn is recommended whenever adequate ecbolic infusions fail to induce myometrial contractions.