Proposal of a new parameter for diagnosing a low-lying placenta in the third trimester: The distance between the external os and placental edge

• Main Authors: Takeshi Nojiri (Author), Toshiyuki Yoshizato (Author), Ayako Sanui (Author), Ryota Araki (Author), Hirotsugu Obama (Author), Kyoko Shirota (Author), Shingo Miyamoto (Author)
• Format: Book
• Published: Elsevier, 2015-08-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

Objective: To validate a new parameter of the distance between the external os (EO) and placental edge (PE) to diagnose a low-lying placenta in the third trimester. Materials and methods: The study participants included 94 uncomplicated singleton pregnant women with cephalic presentation. These women were cared for in our hospital in 1998-2011, with a posterior low-lying placenta, which was diagnosed as the distance between the internal os (IO) and a PE of 0-3.0 cm at 34-36 weeks' gestation. Measurements of cervical length (CL) and the distances of IO-PE and EO-PE were performed using transvaginal ultrasonography at least twice at 28-30 weeks, 31-33 weeks, and 34-36 weeks. Changes in CL, and the IO-PE and EO-PE distances were analyzed. Results: CL and the IO-PE and EO-PE distances did not change prior to 31-33 weeks. CL was shortened and the IO-PE distance was increased after 31-33 weeks (p = 0.0001), but the EO-PE distance was unchanged. Conclusion: The EO-PE distance is a promising parameter for diagnosis of low-lying placenta in the third trimester up to 36 weeks' gestation.

Item Description

1028-4559
10.1016/j.tjog.2013.11.011