Abstract:

The term angular pregnancy is rare and can lead to severe obstetric complications, including uterine rupture and abnormal placental implantation, which can cause massive bleeding and threatening the life of the pregnant woman. If an angular pregnancy is not diagnosed in a timely fashion in the first trimester, misdiagnosis is more likely due to the absence of typical ultrasound imaging characteristics in the second trimester. We herein report two rare cases involving term angular pregnancies that were not diagnosed during routine antepartum care. In both cases, dystocia impeded vaginal delivery, leading to emergency cesarean sections during which term angular pregnancies were diagnosed. Placental adhesions were noted, and the placenta were both delivered manually with difficulty. A figure-of-8 suture was used to reinforce the weakened area of the uterine angle. Favorable maternal and fetal outcomes were achieved in both cases. Based on the intraoperative findings and a comprehensive review of the antepartum ultrasound images in the two cases, we hypothesize that "a thickened and confined placenta" and the presence of the "angle folding sign" on coronal plane sonography may be indicative features of an angular pregnancy in the second trimester. These ultrasound features will be valuable in diagnosing angular pregnancies that may have been missed in early pregnancy.

Key words: Pregnancy, cornual, Term birth, Placenta, retained, Tissue adhesions, Ultrasonography