Deepest vertical amniotic fluid pocket at term. Normal values and clinical application.
OBJECTIVE
To determine the normal values of the deepest vertical amniotic fluid pocket (DVP) in term pregnancies and whether a similar relationship to birth weight (BW) exists.


METHODS
Two hundred thirty-one term patients (37-42 weeks) with intact membranes and a normal amniotic fluid index (AFI) were included. DVP was identified and compared to BW, BW > 4,000 g (large for gestational age [LGA]) and BW < 2,500 g (small for gestational age [SGA]). Statistical comparisons and linear regression models were made.


RESULTS
The mean gestational age was 39.6 weeks, and mean BW 3,284 g. Mean DVP was 4.5 cm. This did not vary significantly by gestational age. A positive linear correlation was observed between DVP and BW. DVP was greater for pregnancies with LGA (5.2 vs. 4.3 cm [P < .003]). No difference was observed for SGA. The relative risk for a fetus > 4,000 g when the DVP was > 6 was 4.0 (1.6-9.5) and 15.8 (1.6-157.6) if maternal diabetes was also present. No difference was determined for SGA using a DVP < 2.


CONCLUSIONS
Higher DVP is associated with delivery of an LGA infant, particularly in diabetic women.
Myles
Thomas D
TD
Department of Obstetrics and Gynecology, Texas Tech Health Sciences Center, Amarillo, USA.
Morgan
Jeffrey L
JL
Santolaya-Forgas
Joaquin
J
D000328:Adult; D000653:Amniotic Fluid / Q000000981:diagnostic imaging* / Q000502:physiology*; D001724:Birth Weight / Q000502:physiology*; D005260:Female; D005320:Fetal Macrosomia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight / Q000502:physiology; D007231:Infant, Newborn; D007745:Labor Onset; D016014:Linear Models; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome; D011336:Probability; D011446:Prospective Studies; D012372:ROC Curve; D012016:Reference Values; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D016216:Ultrasonography, Prenatal