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Medline ® Abstract for Reference 15

of 'Physiology of amniotic fluid volume regulation'

Measurement of fetal urine production in normal pregnancy by real-time ultrasonography.
Rabinowitz R, Peters MT, Vyas S, Campbell S, Nicolaides KH
Am J Obstet Gynecol. 1989;161(5):1264.
Serial measurements of fetal bladder volume were obtained by real-time ultrasonography at 2- to 5-minute intervals, and the hourly fetal urine production rate was calculated. The mean hourly fetal urine production rate increased from 5 ml/hr at 20 weeks' gestation to 51 ml/hr at 40 weeks. These values are double those reported in previous studies that measured fetal bladder volumes at 15- to 30-minute intervals because the cycle length is shorter than previously thought.
Harris Birthright Research Centre for Fetal Medicine, Department of Obstetrics and Gynaecology, Kings College School of Medicine, London, England.