Reference values for the single deepest vertical pocket to assess the amniotic fluid volume in the second and third trimesters of pregnancy.
OBJECTIVE
To establish reference values for the single deepest vertical pocket to assess the amniotic fluid volume in the second and third trimesters of pregnancy.


METHODS
We performed a retrospective cross-sectional study with 3554 consecutive singleton low-risk pregnant women between 14 and 41 weeks of gestation. To perform the largest deepest vertical pocket measurement, the transabdominal convex probe was positioned vertical to the uterine contour of abdomen and parallel to the maternal sagittal plane. In order to obtain reference values for the largest deepest vertical pocket measurement and gestational age (GA), we have used a polynomial regression model.


RESULTS
The mean±standard deviation for the largest deepest vertical pocket measurement (cm) ranged from 3.1±1.1 (1.5-4.9) at 14-14+6 to 3.7±1.6 (0-6.7) at 41-41+6 weeks, respectively. A best-fit was a second-degree polynomial regression: largest deepest pocket=-1.478+0.197*GA-0.0030*GA2 (R2=0.014).


CONCLUSIONS
Reference values for the single deepest vertical pocket to assess the amniotic fluid volume in the second and third trimesters of pregnancy in a large heterogeneous population were established.
Alberto Borges
AB
Peixoto
Taciana Mara Rodrigues
TM
da Cunha Caldas
Camila Vieira
CV
Giannecchini
Liliam Cristine
LC
Rolo
Wellington P
WP
Martins
Edward
E
Araujo Júnior
D000328:Adult; D000653:Amniotic Fluid / Q000000981:diagnostic imaging* / Q000502:physiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015233:Models, Statistical; D011247:Pregnancy; D011262:Pregnancy Trimester, Second / Q000502:physiology*; D011263:Pregnancy Trimester, Third / Q000502:physiology*; D012016:Reference Values; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal