Measurement of placental volume with real-time ultrasound in mid-pregnancy.
A new method to measure placental volume in mid-pregnancy using real-time ultrasound is described. The method is an adaptation of the B-mode parallel planimetric technique. The mean error of in vitro measurements on 45 balloons (mean volume 186 mL range: 88-485 mL) was -2.24 mL, standard deviation 6.76 mL. The error standard deviation of in vivo placental volume measurements was 16.4 mL (volume range: 173-396.5 mL). Placental measurements were made on 175 women between 14.3 weeks and 21.4 weeks, menstrual age (MA) and a smooth centile curve derived. Median volume increased linearly from 144 to 329 mL. The size of the ultrasound probe limits the technique to use before 20 weeks, MA.
Howe
D
D
Department of Obstetrics and Gynaecology, Princess Anne Hospital, Southampton, U.K.
Wheeler
T
T
Perring
S
S
D005260:Female; D006801:Humans; D008953:Models, Anatomic; D010920:Placenta / Q000000981:diagnostic imaging*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D015203:Reproducibility of Results; D016216:Ultrasonography, Prenatal / Q000379:methods*