Lm. Hill et al., TRANSVAGINAL SONOGRAPHIC EVALUATION OF FIRST-TRIMESTER PLACENTA PREVIA, Ultrasound in obstetrics & gynecology, 5(5), 1995, pp. 301-303
Citations number
NO
Categorie Soggetti
Acoustics,"Obsetric & Gynecology","Radiology,Nuclear Medicine & Medical Imaging
Our objective was to determine the relationship between the placenta a
nd the internal cervical os in the first trimester. This study include
d ultrasound examinations performed between 9 and 13 weeks' gestation
over a 28-month period. The position of the lower edge of the placenta
with respect to the internal cervical os was recorded for each transv
aginal ultrasound examination. A total of 77 out of 1252 (6.2%) patien
ts had first-trimester placenta previa;four cases persisted until term
. There were no false-negative diagnoses. Our conclusion is that appro
ximately 6.2% of patients will have a placenta previa in the first tri
mester. Transvaginal sonography can exclude a diagnosis of placenta pr
evia after 9 weeks' gestation. The likelihood that a placenta previa w
ill persist until term increases if the placenta covers the internal c
ervical os by greater than or equal to 1.6 cm.