Pregnancy Testing

Amniotic Fluid Volume

When the amount of amniotic fluid is unusually high or low, it may signal a problem with your baby. There are two terms to become familiar with. Oligohydamnios, which means not enough amniotic fluid, is associated with a prolonged rupture of membranes, intrauterine growth restriction, kidney problems and fetal death. Polyhdramnios, which means too much amitotic fluid, is associated with diabetes, multiple gestations, Rh problems, congenital abnormalities and abnormal fetal presentation.

What you need to know

There are two measures of amniotic fluid volume, the amniotic fluid index (AFI) and the single deepest pocket of fluid. When compared, both do a good job of identifying problems. However the AFI is more likely to predict a problem when everything is fine. Women who have AFI are more likely to be identified as oliohydramnios and receive induction and have cesarean surgery for fetal distress without improvements in outcomes.

Procedure

Measurement of amniotic fluid volume is performed during an ultrasound.

References

Magann, E.F., Chauhan, S.P., Doherty, D.A., Magann, M.I., Morrison, J.C. (2007). The evidence for abandoning the amniotic fluid index in favor of the single deepest pocket. American Journal of Perinatology 24(9): 549-55.

Nabhan A.F., Abdelmoula Y.A.(2008) Amniotic fluid index versus single deepest vertical pocket as a screening test for preventing adverse pregnancy outcome. Cochrane Database of Systematic Reviews (COCHRANE DATABASE SYST REV), 2008(3).