Various factors can contribute to low amniotic fluid in pregnancy, including: - Leakage of amniotic fluid (water bag has broken) - Abnormalities of the baby (e.g. chromosomal, infections and problems with the baby's urinary system such as failure of the kidneys and bladder to develop) - Certain drugs ingested by the mother such as NSAIDs (nonsteroidal anti-inflammatory drugs) - Placenta insufficiency, where insufficient nutrients and oxygen are being passed on to the baby through the placenta, which results in the baby not producing enough fluid.