Polyhydramnios

　　To date, the causes of polyhydramnios have not been clearly identified, especially for mild cases. The following are some common causes of mild to severe polyhydramnios:

　　(1) Gestational diabetes

　　If you have gestational diabetes and do not control the condition well, you may have an excess of amniotic fluid. About 10% of pregnant women with diabetes are diagnosed with polyhydramnios, usually in the late stages of pregnancy.

　　(2) Twins or multiples

　　If you are carrying twins or multiples, there may also be an excess of amniotic fluid. In cases of twin-to-twin transfusion syndrome, there is a particularly high incidence of polyhydramnios, where one fetus has too little amniotic fluid, while the other has too much.

　　(3) Fetal malformation

　　In rare cases, due to the cause of the disease, although the fetus' kidneys continue to produce urine, the fetus can no longer continue to swallow amniotic fluid. The reasons for the fetus's difficulty in swallowing may include pyloric stenosis, cleft lip, cleft palate, or some gastrointestinal obstruction. Some neurological disorders may also hinder the fetus's swallowing, such as neural tube defects or hydrocephalus.

　　(4) Fetal anemia

　　In rarer cases, excessive amniotic fluid may also be a sign of severe anemia in the fetus due to incompatibility of the RH blood type, infection with infectious rubella, and other diseases. Both of these conditions can be treated by intrauterine blood transfusion. If it is infectious rubella, treatment may not be required, and the baby can recover spontaneously.

　　Generally, the more severe the excessive amniotic fluid, the higher the perinatal mortality rate. In patients with obvious excessive amniotic fluid, the prognosis of newborns is poor. Although ultrasound can detect obvious fetal malformations, serious attention should still be paid to the perinates with normal appearance, because some fetal malformations are difficult to detect by ultrasound, and the incidence rate of chromosomal abnormalities is high. The incidence rate of complications such as preterm birth, umbilical cord prolapse, and placental abruption in patients with excessive amniotic fluid increases, affecting the prognosis of perinates. The combination of gestational diabetes and neonatal polycythemia also leads to poor prognosis of perinates.

　　The main impact of excessive amniotic fluid on pregnant women is placental abruption, uterine contraction weakness, postpartum hemorrhage, and so on. Due to the sudden extraction of a large amount of amniotic fluid, the uterine cavity pressure decreases, causing an imbalance in the pressure between the fetal and maternal sides of the placenta, leading to the rupture of the maternal side blood vessels of the placenta and early placental abruption. The uterus of women with excessive amniotic fluid is often larger, and the muscle cells are excessively stretched. When the amniotic fluid suddenly decreases, the smooth muscle cells cannot contract effectively, leading to uterine contraction weakness. After the baby is delivered, it can lead to postpartum hemorrhage. In addition, the abnormal fetal position of women with excessive amniotic fluid increases the rate of cesarean section.

　　At any time during pregnancy, if a pregnant woman finds that there is too much amniotic fluid, this condition is very likely to be 'excessive amniotic fluid', and the incidence rate of excessive amniotic fluid is about 1%. If the rate of uterine enlargement is faster than the normal value, the doctor may suspect excessive amniotic fluid. Excessive amniotic fluid often causes abdominal discomfort, increased back pain, shortness of breath, severe swelling of the feet and ankles, and other symptoms. If these symptoms occur, the doctor will ask you to undergo an ultrasound examination.

　　Firstly, acute excessive amniotic fluid is less common, and its clinical manifestations are as follows:

　　(1) In the second trimester (commonly seen in 20-24 weeks), the uterus rapidly increases in size within a short period of time.

　　(2) The patient cannot lie flat and symptoms of compression occur.

　　(3) There is abdominal distension, pain, and tension, and even pressure pain, with the skin tight and shiny.

　　(4) The expanded and full veins under the abdominal wall are clearly visible.

　　(5) Edema may occur in the lower limbs and perineum.

　　(6) The fetal position is unclear, and the fetal heart is distant.

　　Secondly, chronic excessive amniotic fluid is more common, and its clinical manifestations are as follows:

　　(1) Most cases occur in the late stage of pregnancy.

　　(2) Due to the slow growth of amniotic fluid, the uterus gradually expands, the symptoms are relatively mild, and most pregnant women can gradually adapt without feeling any discomfort.

　　(3) The fundal height and abdominal circumference can be greater than that of the same gestational period. During the examination, there may be a sensation of liquid tremor, and the fetal position is not easy to feel clear.

　　To avoid the condition of excessive amniotic fluid during pregnancy, expectant mothers should pay attention to the following three points.

　　1. Pay attention to rest and low-salt diet.

　　2. You can take diuretics such as hydrochlorothiazide 25mg, taken orally three times a day, or traditional Chinese medicine that invigorates the spleen, benefits the water, warms the yang, and transforms Qi.

　　3. Pay attention to prevent placental abruption and postpartum hemorrhage.

　　Ultrasound examination is an important auxiliary examination method for excessive amniotic fluid, often through measuring the maximum dark area depth (AFD) or amniotic fluid index (AFI) to evaluate the amount of amniotic fluid. The common diagnostic criteria are that the method of measuring the vertical depth of a single maximum amniotic fluid dark area represents the amount of amniotic fluid shows that the distance between the fetus and the uterine muscle wall increases, the distance between the limbs of the fetus is wider, and the fetus can move freely in the amniotic fluid. It can be considered as excessive amniotic fluid if it exceeds 7cm. However, there are also criteria for diagnosing excessive amniotic fluid as exceeding 8cm. When measuring the amniotic fluid index, the pregnant woman lies on her back with her head elevated 30°, using the umbilicus and the linea alba as the landmark, dividing the abdomen into four quadrants, and measuring the maximum amniotic fluid dark area in each quadrant and adding them together. Chinese data mostly diagnose excessive amniotic fluid as exceeding 18cm, and there are also criteria for diagnosing excessive amniotic fluid as exceeding 20cm. Foreign data also set the standard as the amniotic fluid index being greater than 25cm.

　　1. Ultrasound

　　At the same time, understand whether there is fetal edema, twin-to-twin transfusion syndrome, whether the fetus has structural malformations, fetal size, and whether the placenta has lesions, especially paying attention to the structure of the fetal digestive tract and central nervous system.

　　2. Umbilical vein puncture

　　Umbilical vein puncture directly detects fetal indicators, reflecting whether the fetus has anemia, hemolysis, or infection in utero, which helps to clarify the cause of excessive amniotic fluid. However, the operation has certain maternal and fetal complications, and the technical operation is relatively difficult, with certain limitations in clinical application.

　　3. Amniocentesis

　　The method of amniocentesis is to extract fetal shedded epithelial cells from amniotic fluid, and then to detect and analyze the chromosomes of amniotic fluid cells by culturing or applying fluorescence in situ hybridization technology (FISH), to screen for chromosomal diseases. In addition, when it is impossible to perform umbilical vein puncture to draw umbilical blood, amniotic fluid can be selected, and the amniotic fluid can be cultured and biochemically examined to understand whether there are reasons such as infection that lead to excessive amniotic fluid.

　　4. X-ray examination, amniocentesis, and alpha-fetoprotein detection

　　Currently, due to the improvement of B-ultrasound diagnostic technology, the above detection methods have little adverse effect on the mother and child and detection accuracy, and are rarely applied in clinical practice.

　　Tips for attention:For excessive amniotic fluid caused by diabetes, incompatibility of maternal and fetal blood types, infection, and other factors, the mother needs to undergo corresponding examinations to clarify the diagnosis and find the cause of excessive amniotic fluid.

　　Patients with excessive amniotic fluid should drink less water, eat less fruit, eat less sweet food, and not eat too much at each meal. They should eat less frequently. Carbohydrate intake should not be excessive, which means not eating too much staple food. They can eat more high-quality protein, such as fish and shrimp, and also eat fresh vegetables and fruits to supplement various vitamins and trace elements. Eating more sea fish is beneficial for the supply of essential fatty acids, and in addition, it is appropriate to supplement coarse grains.

　　1. During the late pregnancy period, in addition to regular meals, snacks and evening meals should be added, such as milk, biscuits, walnuts, fruits, and other foods. The evening meal should be chosen with easily digestible foods.

　　2. Consume an adequate amount of vitamins. In the late stages of pregnancy, sufficient water-soluble vitamins, especially vitamin B1, are needed. If there is a deficiency, it is easy to cause vomiting, fatigue, and insufficient uterine contraction during delivery, leading to a delay in labor.

　　3. Avoid salty, sweet, or greasy foods. Pregnant women should use less salt in their dishes and soups, and pay attention to limiting the intake of foods with a high salt content.

　　4. Avoid spicy foods, such as strong tea, coffee, alcohol, and spicy seasonings.

　　Traditional Chinese medicine and food therapy for treating polyhydramnios has no side effects, but it is not suitable for acute conditions. Polyhydramnios is called 'amniotic fluid edema' or 'uterine fullness', and is recorded in ancient Chinese medical books such as 'TaiChan XinFa'. Traditional Chinese medicine believes that this symptom is due to the spleen deficiency, which cannot transform the water in the body, or the qi is not smooth, breaking the balance of amniotic fluid production and absorption, causing the production of amniotic fluid to be greater than absorption, so it accumulates more and more. The treatment is mainly to invigorate the spleen and remove dampness to achieve the purpose of reducing amniotic fluid.

　　The earlier the symptoms are discovered and treated, the better the effect. Traditional Chinese medicine often uses the classic prescription from 'Qianjin Fang' to regulate and treat, the specific method is: one carp, remove the internal organs, add 15g of Baizhu, 6g of Chenpi, 15g of Fuling, 12g of Danggui, 12g of Baishao, 6g of Shengjiang, boil into a strong decoction, remove the herbs, drink the decoction and eat the fish. It usually takes 3 to 5 doses to have a significant effect. Because the carp meat has the functions of invigorating the spleen and stomach, promoting diuresis and reducing swelling, and Baizhu, Fuling, Shengjiang, Chenpi have the functions of invigorating the spleen and regulating the qi,配合Danggui, Baishao can nourish the blood and tranquilize the fetus, which can achieve the dual effect of removing water without harming the fetus. In addition, the decoction of winter melon skin, white adzuki bean, and red bean water can also be used for diuresis to reduce the amount of amniotic fluid.

　　Although traditional Chinese medicine and food therapy have few side effects and can produce obvious therapeutic effects, it is only recommended for pregnant women with chronic amniotic fluid abnormalities to try, and the early treatment effect is better. For those with abnormal symptoms of rapid increase or decrease in amniotic fluid, it is still necessary to deal with them early according to the gestational age and the condition of the mother and child. For example, when the amniotic fluid is obviously insufficient and the pregnancy is full term, consider terminating the pregnancy and inducing labor or cesarean section.