Intrauterine growth restriction

　　The causes of intrauterine growth restriction of the fetus include maternal factors, fetal factors, and placental and umbilical cord factors.

　　1. Maternal factors

　　40% of the difference in fetal weight comes from the genetic factors of both parents, and the genetic factors of the pregnant woman have a greater impact, related to the pre-pregnancy weight, age during pregnancy, and parity. If the pre-pregnancy weight is less than 54kg, if the weight is too small or too large during pregnancy, the chance of intrauterine growth restriction of the fetus increases. Malnutrition of pregnant women, especially insufficient supply of protein and energy, chronic hypoxemia or low oxygen transport capacity, pregnancy complicated with kidney disease, severe anemia, severe heart disease, pregnancy-induced hypertension syndrome, chronic hypertension, and various chronic vascular diseases can affect the blood flow and function of the uterus and placenta, leading to fetal malnutrition, immune diseases, endocrine diseases, infectious diseases, and affecting the growth and development of the fetus.In addition, adverse habits such as smoking, alcoholism, drug abuse, and poor social and economic conditions can increase the chance of intrauterine growth restriction of the fetus..

　　2. Fetal factors

　　If the fetus has a genetic disease or a history of chromosomal abnormalities, intrauterine growth restriction of the fetus may appear earlier, such as trisomy 21, 18, or 13, Turner syndrome, etc. Infections by pathogenic microorganisms such as rubella virus, cytomegalovirus, herpes simplex virus, toxoplasma, and syphilis spirochete can lead to intrauterine growth restriction of the fetus. Twin pregnancy can also lead to intrauterine growth restriction of the fetus.

　　3. Placental and umbilical cord factors

　　Placental infarction, inflammation, dysfunction, long and thin umbilical cord, knotting, twisting, and other factors are not conducive to the fetus obtaining nutrition, and can also lead to intrauterine growth restriction of the fetus.

　　Intrauterine growth restriction of the fetus can lead to a decrease in the number of fetal cells or abnormal cell size, resulting in small-for-gestational age or macrosomia. Severe cases can affect the development of the child's nervous system, such as delayed brain development and low intelligence.

　　When pregnant women have intrauterine growth restriction of the fetus, they may have malnutrition in the middle trimester, accompanied by conditions such as pregnancy-induced hypertension, multiple pregnancies, polyhydramnios, pregnancy hemorrhage, kidney disease, cardiovascular disease, diabetes, or infection; a history of congenital malformation or intrauterine growth restriction delivery. After 28 weeks of pregnancy, pregnant women should measure the fundal height weekly, and if it is less than the 10th percentile for two consecutive times, or if the weight does not increase for three consecutive times, intrauterine growth restriction of the fetus should be suspected.

　　To prevent intrauterine growth restriction of the fetus, pregnant women should strengthen nutrition, maintain a balanced diet, a regular lifestyle, and keep a pleasant mood. In cold weather, it is necessary to add clothes in time to prevent colds. Those with acute or chronic diseases should wait until they recover before becoming pregnant.

　　1. Strengthen nutrition, increase sufficient weight during pregnancy, which may mean you need to change your diet habits and experience changes in body shape.

　　2. Quit smoking before pregnancy and avoid secondhand smoke. Tobacco can damage the placenta, which is the only pathway for the baby to obtain 'food'. Quitting smoking is never too late. Half of the baby's birth weight is obtained in the last three months of pregnancy.

　　3. Stop drinking immediately. Even a day of drinking during pregnancy can cause developmental delay in the baby. Alcohol can also harm the baby's brain. It is necessary to guard against the dangers of alcohol at any time during pregnancy.

　　4. Immediately quit addictive drugs. Almost all addictive drugs can cause intrauterine growth restriction of the fetus. If withdrawal symptoms occur when quitting drugs, consult with a doctor.

　　5. Once pregnant, undergo pre-pregnancy checks and regular prenatal checks.

　　6. Follow the doctor's advice and opinions during pregnancy.

　　7. Pay attention to the prevention and treatment of diseases such as pregnancy-induced hypertension and nephritis during pregnancy to avoid affecting uteroplacental blood supply.

　　8. If you plan to undergo assisted reproductive technology, understand the advantages and risks of the procedure, and be aware that it may result in multiple pregnancies (multiple pregnancies often lead to premature birth).

　　9. Consult with the doctor about screening tests for mild reproductive organ infections in the early stages of pregnancy.

　　10. Consider having another child 18 months after the first child or after a miscarriage.

　　Prenatal examinations should measure fundal height weekly after 28 weeks of pregnancy. If it is less than the 10th percentile for two consecutive times or if the weight of the pregnant woman does not increase for three consecutive times, it should be suspected that the fetus is experiencing intrauterine growth restriction. The patient can also undergo the following examinations:

　　1. B-ultrasound to measure the biparietal diameter, chest circumference, abdominal circumference, and femur length of the fetus and other indicators.

　　2. NST (No-stimulation fetal heart monitoring. and OCT detection (Oxytocin challenge test. A fetal heart abnormality may occur, such as late deceleration and variable deceleration, indicating intrauterine growth restriction of the fetus.

　　3. Measure the blood flow velocity of the umbilical artery of the fetus using Doppler ultrasound, and consider it abnormal if the S/D ratio is greater than 3 in the later stages of pregnancy.

　　4. Determine urinary estriol (E3 or E/C ratio) and placental lactogen (hPL).

　　5. Check the blood glucose level of the pregnant woman, and perform a glucose tolerance test if necessary.

　　6. Check amniotic fluid for creatinine, fat cell count, phospholipid/sphingomyelin (L/S) ratio, and foam test, combined with genetic counseling. If necessary, perform amniotic fluid cell chromosome culture and karyotype analysis.

　　To prevent intrauterine growth restriction of the fetus, pregnant women should strengthen their diet and nutrition, ensure the intake of calories, and receive high-nutrition treatment in the hospital if necessary, which includes intravenous administration of glucose, energy preparations, vitamins, and other nutrients to improve the nutritional status of the mother and fetus, and correct nutritional disorders in the fetus. In the monitoring of intrauterine growth restriction of the fetus, in addition to observing the growth and development of the fetus, attention should also be paid to the presence of fetal hypoxia, and fetal heart monitoring should be performed if necessary. Pregnant women should not only consume sufficient carbohydrates and protein foods but can also appropriately increase fatty foods, and it is particularly necessary to supplement trace elements such as calcium, iron, zinc, and phosphorus, such as animal liver, seafood, and bone soup.

　　If fetal intrauterine growth retardation is found, the patient needs to rest in a left lateral position, intermittent oxygen inhalation, 1 hour each time, 2-3 times a day.

　　I. Drug Treatment

　　1. Theophylline 2.4mg, oral, 3 times a day. 7 days is one course of treatment.

　　2. 500ml of low molecular dextran and 8-16ml of Salvia miltiorrhiza injection added to 250ml of 5% glucose solution for intravenous drip, once a day, 7 days is one course of treatment. To improve microcirculation and placental function.

　　3. 100ml of amino acid solution, intravenous injection, once a day. 7 days is one course of treatment.

　　II. Strengthened Monitoring

　　1. Observe fetal movement, 3 times a day.

　　2. Fetal monitoring, at least once a week with NST, and OCT should be performed for unreactive NST. Pregnancy should be terminated appropriately if OCT is positive.

　　3. Ultrasound monitoring, amniotic fluid index or maximum depth of amniotic fluid pool, once a week.

　　4. Urinary E3 or E/C ratio determination, once a week.

　　III. Obstetric Management

　　1. If the fetal growth and placental function are good after treatment, pregnancy can be continued, but not beyond the due date.

　　2. If the treatment is ineffective and there are abnormalities in the determination of fetal placental function, prednisone or dexamethasone should be administered 1 to 2 days before delivery to promote fetal lung maturation, and pregnancy should be terminated as soon as possible.

　　3. In the following situations, cesarean section should be performed immediately to end labor:

　　(1) NST is unreactive, and CST is positive.

　　(2) Ultrasound examination shows oligohydramnios, and there is amniotic fluid with fecal pollution degree 2 or above.

　　(3) Pregnant women with growth retardation of the fetus, concurrent with other high-risk factors, and severe illness or with obstetric abnormalities.