Too little amniotic fluid of 1.8 centimeters will have an effect on the fetus, which may lead to pulmonary hypoplasia, malformation of organ development, malformation of bone development and so on. 1. Pulmonary hypoplasia: amniotic fluid promotes the development of fetal lungs, therefore, too little amniotic fluid may lead to fetal pulmonary hypoplasia, and in serious cases, it may even have an impact on the normal establishment of postnatal respiration of the fetus. 2. Malformation of organ development: too little amniotic fluid will limit the growth environment of the fetus, which may cause developmental defects of the fetus’ limbs, physical appearance, face and other aspects. 3. Skeletal deformities: Decreased amniotic fluid will also cause the fetus to have limited movement, curled position, inability to roll over, etc., which may adversely affect its skeletal development. Pregnant women are advised to undergo regular checkups during pregnancy and seek medical attention promptly if amniotic fluid is found to be decreased, so as to avoid serious consequences.