The amniotic fluid is the protective liquid that serves as a cushion for the growing foetus. It also facilitates the exchange of nutrients water and biochemical products between mother and foetus. The health and well-being of your baby is determined by the amount of fluid present in the amniotic sac. Low amniotic fluid (oligohydramnios) is a condition in which the amniotic fluid measures lower than expected for a baby's gestational age. This condition can occur at any time during pregnancy but it is most common during the last trimester. Having low amniotic fluid can put you or your baby at