The amount of normal amniotic fluid varies with the period of gestation. For example, at about 4 months of gestation, the volume of amniotic fluid is about 200 ml; at about 7 months, it is about 1000 ml; in late gestation, the volume of amniotic fluid gradually decreases, and by 37 weeks of gestation, the volume of amniotic fluid can be reduced to 800 ml. When the volume of amniotic fluid is less than 300 ml at full term, it is called hypohydramnios. This can cause a number of problems at this point. Because amniotic fluid is the environment for the baby’s growth and development, it has the ability to cushion the external pressure and protect the baby from shock; it also prevents the baby’s body and amniotic membrane from sticking together, which facilitates the baby’s normal development; it also helps dilate the cervix and clean and lubricate the birth canal during delivery. Therefore, too little amniotic fluid is not conducive to the normal development of the baby and delivery. Since too little amniotic fluid is so dangerous, and to correct the situation, we must first find the cause. Causes of low amniotic fluid: Baby’s problems: such as baby’s urinary system abnormalities, including congenital infantile polycystic kidney, renal agenesis, urinary tract obstruction, etc. A significant percentage (about 1/3) of low amniotic fluid is related to this factor, especially in those who develop severe, stubborn low amniotic fluid relatively early. Problems of the mother: Low amniotic fluid can be caused by the mother’s insufficient blood volume or by a combination of certain diseases. For example, if the mother is chronically hypoxic (e.g., combined with certain cardiovascular and respiratory diseases), has severe anemia or blood loss, the blood flow to the organs of the body decreases and serum penetrates into the amniotic cavity, resulting in a natural decrease in the amount of amniotic fluid. Further, if the mother has gestational hypertension, placental hypofunction, placental edema, etc., this can also lead to low amniotic fluid. Recently, it has been found that some mothers’ blood tests show excessive hypercoagulation, when the blood can easily clot to form some very tiny emboli that block the tiny blood vessels, thus reducing the placental blood supply and affecting the formation of amniotic fluid. Finally, long-term use of certain medications (such as non-steroidal anti-inflammatory drugs, angiotensin-converting enzyme inhibitors, etc.) can affect the baby through the placenta, causing a decrease in the baby’s urine production and thus causing low amniotic fluid. Of course, if there is an early rupture of the fetal membranes and a constant leakage of amniotic fluid, this will obviously result in a significant loss of amniotic fluid. Most pregnant women with too little amniotic fluid generally do not experience significant discomfort, so it is usually discovered during the maternity checkup by the doctor’s physical examination or ultrasound. However, individual mothers-to-be may feel that their bellies are increasing at a slower pace and that the sensation of fetal movement is more pronounced than before, and sometimes one fetal movement can cause significant abdominal pain. This is caused by the loss of the buffering effect of amniotic fluid and the force of fetal movement directly acting on the local uterine wall to stimulate uterine contraction. During the labor check, it is often found that the uterine height and abdominal circumference are significantly smaller than the corresponding number of weeks of menopause, and the feeling of floating uterus is not obvious when the abdomen. At this time, doctors often recommend that pregnant women have an ultrasound examination to accurately estimate the amount of amniotic fluid. Hypertensive disorders, diabetes, kidney disease, lupus erythematosus and other diseases during pregnancy can also cause low amniotic fluid. Therefore, for these pregnant women, it is even more important to have an ultrasound every once in a while to detect low amniotic fluid in a timely manner. Treatment of low amniotic fluid is related to the number of weeks of gestation. Low amniotic fluid found in the middle of pregnancy is often combined with a baby abnormality and requires careful examination (e.g., cord blood or amniotic fluid chromosome tests to rule out chromosomal abnormalities). Once the possibility of baby malformation has been ruled out, the baby can be closely monitored in utero and the amount of amniotic fluid changes. If the low amniotic fluid is due to insufficient maternal blood volume or hypoxia, drinking large amounts of water, intravenous fluids and oxygen can indeed be helpful. For mothers with hypercoagulability, subcutaneous injection of low molecular heparin or intravenous infusion of low molecular dextrose can be used to make the blood less likely to clot and to facilitate the formation of amniotic fluid by allowing the placenta to circulate more smoothly. If necessary, intra-amniotic infusion therapy can also be used, i.e., an appropriate amount of saline can be injected into the amniotic cavity through the abdomen with a puncture needle under ultrasound guidance to improve the condition of low amniotic fluid. This method is now also increasingly recognized and adopted, especially for pregnant women with unexplained low amniotic fluid at an early stage, where the baby is immature and amniotic fluid infusion can improve the effects of low amniotic fluid on the baby and maintain normal development in a short period of time. However, these treatments must be preceded by a thorough evaluation and the treatment must be performed in a hospital under close monitoring to prevent adverse reactions such as allergic reactions, bleeding tendencies, preterm labor, miscarriage, and infection. If the amniotic fluid is found to be too low in late pregnancy, and after ruling out any malformation of the baby, the intrauterine condition of the baby can be evaluated in detail to promote fetal lung maturation, and the pregnancy should be terminated as soon as the baby is mature. The termination of pregnancy can be either vaginal induction of labor or cesarean section, depending on the baby and the state of the mother. In this case, most of them can deliver a healthy baby without any problems.