What are the causes of polyhydramnios or oligohydramnios?

Generally, polyhydramnios (excessive amniotic fluid) or oligohydramnios (insufficient amniotic fluid) may result from individual physiological differences, changes in gestational age, gestational diabetes mellitus, fetal urinary system malformations, placental dysfunction, and other factors. It is recommended to seek timely medical consultation to identify the underlying cause and receive symptomatic treatment under a physician's guidance. Detailed explanations are as follows:

1. Individual physiological differences: Some pregnant women naturally have more or less amniotic fluid due to their unique metabolic characteristics, without other abnormal symptoms. This is considered a normal physiological phenomenon. No special treatment is required; regular ultrasound examinations should be conducted to monitor changes in amniotic fluid volume.

2. Changes in gestational age: Amniotic fluid volume naturally fluctuates with the progression of pregnancy, gradually decreasing after 38 weeks of gestation. If within the normal range, it is considered a physiological fluctuation. Follow the physician's advice for regular prenatal checkups, ensure adequate rest, and avoid excessive fatigue.

3. Gestational diabetes: Poorly controlled maternal blood glucose levels can lead to elevated fetal glucose levels, resulting in increased fetal urine output and excessive amniotic fluid, which may be accompanied by fetal macrosomia. Patients should manage their diet, reduce intake of high-sugar foods, and, if necessary, follow medical advice to use medications such as insulin injection, coenzyme A for injection, and glyburide tablets to control blood glucose levels.

4. Fetal urinary system malformations: Fetal urinary tract obstructions, underdeveloped kidneys, and other malformations can cause abnormal urine production or excretion, leading to reduced amniotic fluid, which may be accompanied by other structural abnormalities. Further diagnostic evaluation of the fetus is necessary. Mild malformations may be treated surgically after birth, such as urethroplasty. Severe cases should be managed according to medical advice.

5. Placental dysfunction: Placental aging or reduced function can lead to insufficient blood supply to the fetus, resulting in decreased amniotic fluid production, which may be accompanied by fetal growth restriction. Close monitoring of fetal heart rate and fetal movements is required. Follow medical advice to use medications such as low molecular weight heparin sodium injection, coenzyme A injection, and vitamin E soft capsules to improve placental function. Cesarean section may be necessary when indicated.

Pregnant women should maintain a balanced diet, drink an adequate amount of water, and avoid excessive water restriction or excessive water intake. Additionally, they should maintain regular sleep patterns, avoid staying up late, and engage in appropriate walking to promote blood circulation. Strict adherence to the prenatal checkup schedule is essential for timely detection and management of amniotic fluid abnormalities, ensuring maternal and fetal safety.