How can too little amniotic fluid cause fetal deformities?

A deficiency in amniotic fluid, known as oligohydramnios, causes fetal deformities primarily by removing the protective buffer that shields the fetus from the pressure of the uterine wall.12

When this fluid is insufficient, the uterine wall and membranes can press directly against the developing fetus, leading to secondary changes in shape and structure. The resulting deformities may include:12

• Skeletal and Joint Issues: Compression can cause clubfoot, wryneck, and fixation of the joints, such as clubbed hands or arthrogryposes (contracted joints).12
• Physical Distortions: The fetus may experience growth retardation and flattening of the nose and ears due to external pressure.2
• Organ Underdevelopment: The lack of space and fluid can lead to the underdevelopment of the lungs and gut.2

If the condition occurs early in pregnancy, it can cause firm adhesions between the membranes and the embryo, resulting in significant fetal distortion. Additionally, defective kidney development is frequently associated with this condition.1