Premature Birth

　　About 30% of preterm births have no obvious cause, and common triggering factors include:

　　1. Regarding the pregnant woman

　　(1) Overly dilated uterus, twins or multiple pregnancies, and excessive amniotic fluid can increase the intrauterine pressure, leading to premature labor.

　　(2) Incomplete closure of the cervical os: Anatomically, there is no true sphincter-like arrangement at the cervical site, and the main component of the connective tissue is collagen fibers, which are strong and have a sphincter-like effect on the pregnant cervix. During the second trimester, as the isthmus extends to form the lower uterine segment, the internal os of the cervix relaxes and the amniotic cavity pressure gradually increases, causing the cervical os to dilate passively. The amniotic sac bulges into the cervical canal due to changes in tension or infection factors, leading to premature rupture of membranes and preterm labor.

　　(3) Complications of acute or chronic diseases, such as viral hepatitis, acute nephritis or pyelonephritis, acute appendicitis, viral pneumonia, high fever, rubella, and other acute diseases; heart disease, diabetes, severe anemia, hyperthyroidism, hypertension, asymptomatic bacteriuria, and other chronic diseases.

　　(4) Congenital uterine malformations (such as bicornuate uterus, septate uterus), cervical relaxation, and uterine fibroids.

　　(5) Pregnancy complicated with chronic nephritis, heart disease, hepatitis, and systemic lupus erythematosus, on one hand, can cause maternal systemic anemia and hypoxia due to internal medical complications, and insufficient placental perfusion, which is prone to preterm labor; on the other hand, the severity of the disease poses a risk to the mother, and iatrogenic preterm labor may occur to ensure the safety of the mother.

　　(6) Complications of pregnancy such as placenta previa, early placental abruption, pregnancy-induced hypertension syndrome, and intrahepatic cholestasis of pregnancy.

　　(7) Smoking, drug abuse, alcoholism, and severe malnutrition.

　　(8) Other factors such as long-distance travel, climate change, living in high-altitude areas, family relocation, and dramatic emotional fluctuations, which can cause physical and mental stress; direct abdominal impact, trauma, sexual intercourse, or surgical operation stimulation.

　　2. Fetal-placental aspect

　　(1) Placenta previa and placental abruption.

　　(2) Excessive or insufficient amniotic fluid, multiple pregnancy.

　　(3) Fetal malformation, intrauterine fetal death, abnormal fetal presentation.

　　(4) Premature rupture of membranes, chorioamnionitis.

　　The complications of preterm labor are also many, and they will seriously affect the physical health of the baby. Since the organs and systems of premature infants are not fully developed, their vitality is poor, and they are prone to diseases such as lung diseases, intracranial hemorrhage, infection, and hardening syndrome, which can leave intellectual disabilities or sequelae of the nervous system, and about 15% of premature infants die in the neonatal period, and preterm labor is an important cause of perinatal mortality.

　　Preterm labor patients have uterine contractions, a small amount of vaginal bleeding, often accompanied by early rupture of the amniotic membrane, the cervical canal gradually shortens and then dilates, and pregnant women with a history of miscarriage or preterm labor or vaginal bleeding during this pregnancy are prone to preterm labor. Preterm labor is similar to miscarriage, and it also has a development process, which can be divided into two stages in clinical practice:

　　1. Preterm labor

　　In the middle and late stages of pregnancy, sensitive pregnant women can feel uterine contractions. This type of uterine contraction with no fixed interval and irregular duration is not the contraction that indicates the onset of labor, but the physiological manifestation of the uterus, or called Braxton-Hick's contraction. If the interval between uterine contractions is within 10 minutes, there is a tendency to shorten gradually, the duration of contraction is 20-30 seconds, and there is a tendency to prolong, it can be considered as the manifestation of preterm labor. Sometimes it is even accompanied by the discharge of vaginal secretions, dilatation of the cervix, or early rupture of the amniotic membrane.

　　2. Inevitable preterm labor

　　In addition to regular uterine contractions, the interval shortens gradually, the duration increases gradually, and the intensity increases continuously, accompanied by cervical dilation ≥75% and cervical dilation ≥2cm; or progressive cervical dilation and cervical dilation, accompanied by vaginal bloody discharge or rupture of the amniotic membrane, the situation is similar to that of full-term pregnancy.

　　Preterm labor is preventable, the key is to diagnose and treat it early. When one of the following three situations occurs, you must go to the hospital for a check-up.

　　(1) Hardening of the lower abdomen

　　In the late stage of pregnancy, with the expansion of the uterus, irregular uterine contractions may occur, which are usually painless. The characteristic is that they often appear frequently at night and disappear the next morning, known as physiological uterine contractions, which will not cause preterm labor. If the lower abdomen softens and hardens repeatedly, and there is a feeling of hardness and swelling in the muscles, at least one contraction every 10 minutes for more than 30 seconds, accompanied by shortening of the cervical canal, it is a sign of preterm labor, and you should go to the hospital as soon as possible for a check-up.

　　(2) Vaginal bleeding

　　A small amount of bleeding is one of the signs of impending labor, but vaginal bleeding can also occur in cases of cervical inflammation, placenta previa, and placental abruption. At this time, the amount of bleeding is considerable, and you should go to the hospital for a check-up immediately.

　　(3) Rupture of membranes

　　A liquid resembling warm water is flowing out, which is an early sign of rupture of membranes, but generally speaking, labor pains start immediately after rupture of membranes. At this time, it is best to elevate the buttocks and lie flat, and go to the hospital immediately.

　　After 28 weeks of pregnancy, pregnant women should not do anything that is harmful to their babies to avoid preterm labor. During pregnancy, they should strengthen nutrition, avoid mental trauma, not smoke, not drink alcohol, and avoid passive smoking. Sexual intercourse is strictly prohibited in the late pregnancy period because the prostaglandins in semen can promote uterine contractions after absorption through the vagina. Once signs of preterm labor appear, they should rest in bed immediately and assume a left lateral position to increase the blood supply to the placenta and uterus; if possible, they should be hospitalized for fetal protection. The fourth is to actively treat acute and chronic diseases.

　　Pregnancy is a very important event for women. The body of pregnant women is relatively complex, so it is necessary to do relevant examinations to prevent preterm labor. The phenomenon of preterm labor is relatively common, as it can cause great harm to women's bodies. Therefore, the examination for preterm labor must be meticulous to avoid the occurrence of preterm labor. So what are the examination and diagnosis methods for preterm labor?

　　1. Measure tumor necrosis factor (TNF)

　　TNF is a cytokine produced by macrophages after stimulation, which can stimulate the amnion and decidua to produce prostaglandins. Therefore, it is considered that the measurement of TNF in amniotic fluid is much more sensitive than Gram staining for the diagnosis of microbial invasion. Once there is microbial invasion in the amniotic fluid, it stimulates the secretion of cytokine TNF into the amniotic fluid, and delivery is inevitable. Therefore, the presence or absence of TNF in amniotic fluid can be used to predict preterm labor.

　　2. Measure fetal fibronectin

　　Fetal fibronectin (FFN) is a protein synthesized by the chorionic villous decidua tissue. By using sensitive immunological determination (monoclonal antibody FDC-6), FFN > 50mg/L in the cervical or vaginal secretions, amniotic fluid, and maternal plasma during the late pregnancy period indicates the possibility of preterm labor. It indicates that under the action of uterine contractions, or due to the rupture of the fetal membrane, the separation of the chorion from the decidua, the release of intact or degenerated villous components, and their entry into the cervical and vaginal secretions.

　　3. Measure insulin-like growth factor binding protein-1

　　Insulin-like growth factor binding protein-1 (IGFBP-1) is a secretory protein secreted by the basal cells of the endometrium of the decidua. It has been found that decidua cells and human liver secrete a large amount of phosphorylated IGFBP-1, while amniotic fluid, fetal serum, and maternal plasma contain abundant non-phosphorylated IGFBP-1. As delivery approaches, the fetal membrane begins to separate from the decidua wall, and the decidua and the chorion adhered to it are decomposed into small fragments. A small amount of phosphorylated IGFBP-1 leaks into the cervical secretions. The content of phosphorylated IGFBP-1 in cervical-vaginal secretions ≥ 50μg/L can be used as a predictor of preterm labor.

　　4. Measure prolactin

　　Prolactin (prolactin, PRL) is synthesized by the decidua, maternal pituitary, and fetal pituitary during pregnancy and is transported into the amniotic cavity through the decidua to promote the synthesis of prostaglandins and the maturation of the fetal lungs. The presence of PRL in the cervical-vaginal secretions of pregnant women indicates the separation of the decidua from the amnion, leakage of PRL, or damage or rupture of the amnion due to certain factors, causing the leakage of PRL into the amniotic cavity. Theoretically, it can be used as a means to predict preterm labor.

　　5. B-ultrasound

　　The diagnostic criteria for B-ultrasound examination, for a long time, the understanding of cervical dilation and retraction degree has relied mainly on the traditional Bishop score. However, the disadvantages of finger examination lie in poor objectivity and repeatability, and it can only explore the situation of the cervical vaginal part, and cannot understand the whole length of the cervix. With the development of ultrasound technology, a new way has been opened up for the objective evaluation of cervical maturity. Transvaginal and perineal ultrasound are superior to abdominal ultrasound. After studying the ultrasound image changes in 48 cases of preterm labor pregnant women, Bactolucci et al. proposed 4 signs of preterm labor: cervical length 1cm, amniotic sac protruding into the cervical canal, uterine lower segment thickness

　　To prevent preterm labor and miscarriage in pregnant women, their dietary arrangements should be scientific and reasonable. Pregnant women should eat more spinach, the best vegetable for preserving the fetus. In the first two months of pregnancy, more spinach or folic acid tablets should be taken. However, spinach also contains a lot of oxalic acid, which can interfere with the absorption of trace elements such as iron and zinc in the human body. The spinach can be scalded in boiling water to destroy most of the oxalic acid. Do not forget to eat the best food to prevent preterm labor: fish. Surveys have found that the probability of preterm labor is only 1.9% for pregnant women who eat fish once a week during pregnancy, while the probability of preterm labor is 7.1% for pregnant women who never eat fish. Lotus seeds are the most effective for preventing preterm labor, miscarriage, and lower back pain in pregnant women.

　　Pregnant women should avoid using spices such as fennel, Sichuan pepper, black pepper, cassia bark, chili, garlic, etc., which are spicy and hot. Eat less hawthorn: hawthorn can accelerate uterine contraction and may lead to preterm labor, so it is best to 'keep it at a distance'. Pregnant women should not consume too much vitamin A, as it may cause preterm labor and incomplete fetal development. Pork liver is rich in vitamin A, and excessive intake should be avoided. Avoid eating black fungus: it has the function of activating blood circulation and removing blood stasis, which is not conducive to the stability and growth of the embryo. Avoid eating apricots and apricot kernels: apricots are sour and hot, and have the effect of滑胎, which is a taboo for pregnant women. Avoid eating slippery foods: Coix Seed and Porcelainwort. Coix Seed has an excitatory effect on the uterine muscle, which can promote uterine contraction and may induce preterm labor. Porcelainwort is cool and slippery, and has a significant excitatory effect on the uterus, which is easy to cause preterm labor.

　　Traditional Chinese medicine treatment for preterm labor is divided into 5 types, namely kidney deficiency type, Qi and blood deficiency type, blood heat type, injury and external pathogenic toxin type.

　　1. Kidney deficiency type

　　In the middle and late stages of pregnancy, there may be symptoms such as acid and坠 sensation in the lower back and abdomen, colicky pain in the lower abdomen, a sense of constant pressure, or leakage of amniotic fluid or small amounts of dark red vaginal bleeding, frequent urination, tinnitus, pale tongue with white fur, and deep, thin, and slippery pulse.

　　The treatment should benefit the kidney and tranquilize the fetus, using modified Bushen An Tai Decoction: 15 grams each of Cuscuta, Codonopsis, Aconitum, and Eucommia, 20 grams of Bai Shao, 12 grams each of Bai Zhu, Du Zhong, and Sang Ji Sheng, and 6 grams of Gan Cao. Add 10 grams each of Yu Zhi Ren and Fu Pen Zi for incontinence of urine. Take one dose daily, decocted in water for oral administration, twice a day.

　　2. Qi and blood deficiency type

　　In the middle and late stages of pregnancy, there are symptoms such as lower abdominal distension and soft limbs, or slight light red vaginal bleeding, palpitations, shortness of breath, poor appetite and loose stools, pale tongue with white fur, and weak and无力pulse.

　　Treatment should be tonifying Qi and nourishing blood to tranquilize pregnancy, using补中安胎饮with modification: dangshen, astragalus, raw rehmannia each 15 grams, white peony 20 grams, scutellaria, dodder each 12 grams, suqin, licorice each 6 grams. Add 15 grams of ejiao if there is bleeding; add 20 grams of yam if there is poor appetite and loose stools; add mulberry seedling and prunella each 12 grams if there is lumbago and soft limbs. Take one dose daily, decocted for oral administration, twice a day.

　　3. Blood-heat type

　　In the middle and late stages of pregnancy, there are symptoms such as fetal descent, fresh red vaginal bleeding, dry mouth and thirst, less urine and constipation, or five heart restlessness, red tongue with thin yellow fur, slippery and rapid pulse, and other symptoms.

　　Treatment should be nourishing blood and clearing heat to tranquilize pregnancy, using Bao Yin Decoction with modification: yam 20 grams, hemp root 30 grams, herba epimedii, white peony, cypress carbon, raw rehmannia each 15 grams, prunella, scutellaria, phellodendron, dodder, ejiao each 10 grams. Add 10 grams of ophiopogon and poria if there is restlessness; take one dose daily, decocted for oral administration, twice a day.

　　4. Trauma

　　Obvious external factors cause abdominal pain and bleeding in the late stage of pregnancy, desire to fall, lumbago, normal tongue fur or wiry slippery pulse, dark tongue, and other symptoms.

　　Treatment should be tonifying Qi and blood, consolidating kidney and tranquilizing pregnancy, using Shoutai Pill with modification: dodder, mulberry seedling, ejiao, astragalus each 15 grams, baizhu, dangshen each 10 grams, hemp root, prunella each 12 grams. Add 6 grams of mugwort carbon if there is severe bleeding; if there is stasis due to injury, add 5 grams of amomum and 6 grams of cyperus; if the fetus is difficult to retain or there is already a fetus block excreted, or there is more bleeding, it is advisable to use Shenghua Decoction with modification. Take one dose daily, decocted for oral administration, twice a day.

　　5. External Pathogenic Toxins

　　In the late stage of pregnancy, there are symptoms such as lower abdominal pain, aversion to cold, fever, abundant leukorrhea with yellowish and smelly color, or vaginal bleeding, dark color or smell, bright yellow urine, thick or greasy yellow tongue fur, or slippery and rapid pulse.

　　Treatment should be cooling and detoxifying, kidney-nourishing and tranquilizing pregnancy, using detoxifying tranquilizing drink: honeysuckle, rhizoma tieguanyin, patrinia, raw rehmannia, white peony each 15 grams, dandelion, Prunella, licorice, hemp root each 10 grams, mulberry seedling 30 grams. Take one dose daily, decocted for oral administration, twice a day.