Direct prediction of amniotic fluid volume in the third trimester by 3-dimensional measurements of intrauterine pockets: a tool for routine clinical use.
OBJECTIVE
To develop an ultrasonographic technique for direct prediction of amniotic fluid volume.


METHODS
While women with near-term pregnancies were in the supine position, the intrauterine space was divided into 2 hemispheres and each hemisphere was further subdivided into 3 segments. The maximum distances along the 3 axes of amniotic fluid pocket in each segment were measured, and the volume was calculated as a half-ellipsoid or a crescent-cylinder. A sum of these calculations (prediction of amniotic fluid volume [pAFV]) was made and correlated with amniotic fluid volume measured at delivery (mAFV).


RESULTS
In 714 deliveries, a high correlation coefficient of 0.896 between mAFV (mean +/- SD, 296.5 +/- 199.2 mL; range, 20 to 1480 mL) and pAFV (mean +/- SD, 300.2 +/- 180.8 mL; range, 27 to 1262 mL) was obtained. The regression equation was mAFV = 0.968pAFV + 8.68.


CONCLUSIONS
The regression equation suggested that pAFV could be a direct predictor of intrauterine amniotic fluid volume in the third trimester.
Hombo
Yoshiyasu
Y
Department of Obstetrics and Gynecology, Kanazawa Holy Spirit Hospital, Japan.
Ohshita
Michio
M
Takamura
Shosuke
S
Uchide
Kiyoshi
K
Inoue
Masaki
M
D000653:Amniotic Fluid / Q000502:physiology*; D005260:Female; D005544:Forecasting; D006801:Humans; D021621:Imaging, Three-Dimensional; D016104:Oligohydramnios / Q000000981:diagnostic imaging; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D012044:Regression Analysis; D014463:Ultrasonography; D014599:Uterus / Q000000981:diagnostic imaging*