During pregnancy, the development of the fetus is undoubtedly the most important concern of the mother-to-be. When going to the hospital and hearing that the fetus is too small, the mother-to-be is inevitably worried and nervous, is it caused by her own malnutrition? Or is it due to other reasons? Is there any solution? Is this treatable? The following I will lead all the mothers-to-be to understand the reason for this. 1, how to determine whether the fetus growth restriction? To solve this problem, we must first understand what is “fetal growth restriction”. Fetal growth restriction: A fetus weighing less than the normal weight for its gestational age (under the 10th percentile), or a full-term fetus weighing less than 2500 grams, means that the fetus is growing slowly inside the mother-to-be, which is medically known as fetal growth restriction (FGR). In layman’s terms, the determination of fetal growth retardation depends mainly on the weight of the fetus. The Pediatrics Branch of the Chinese Medical Association conducted a large-scale survey to summarize and analyze the weight of newborns at different gestational weeks, and developed the “Chinese Newborn Weight Curves for Different Gestational Ages”, which can be used by mothers-to-be as a basis for judgment. For example, if the fetal weight at the 10th percentile is 1765 grams at 34 weeks of gestation, if the predicted fetal weight is lower than 1765 grams, it will be diagnosed as fetal growth restriction. Generally we determine the fetal weight mainly by ultrasound, and also do some basic measurements such as uterine height, abdominal circumference, and the mother-to-be’s weight gain to assist in the determination. So the mother-to-be must check the pregnancy week accurately and have regular prenatal checkups to detect the baby’s growth and development. 2.What are the causes of fetal growth restriction? There are many reasons for fetal growth retardation and low weight, mainly including: Fetal malformation If intrauterine growth restriction is diagnosed, if there is no obvious evidence of insufficient placental blood perfusion, patients with positive ultrasound indicators should be examined to exclude fetal malformation and chromosomal abnormalities. Placental factors The placenta is the main source of nutrition for the fetus. Therefore, abnormalities of the umbilical cord (e.g., too thin, too long, twisted, or wrapped around the neck) and various primary or secondary abnormalities of the placenta (e.g., increased number of syncytial nodules in the placenta, avascular chorion, chorionic infarction, etc.) can lead to insufficient placental perfusion and intrauterine growth retardation. Monitoring of blood flow in the umbilical, uterine and middle cerebral arteries can detect these abnormalities. Genetic factors Not all fetuses diagnosed with growth restriction are abnormal, but genetic factors account for about 10%. If the mother or father-to-be is shorter, thinner and lighter, the baby will naturally be lighter in weight. Nutritional factors During pregnancy, if the mother-to-be has a partial diet, vomiting or insufficient intake of protein, vitamins and trace elements, it will affect the growth and development of the fetal baby. The mother-to-be has complications or comorbidities If the mother-to-be has high blood pressure disease during pregnancy, multiple pregnancy, placental abruption, overdue pregnancy, intrahepatic cholestasis during pregnancy, heart disease, nephritis, anemia and other diseases, they may reduce the blood flow to the placenta, thus reducing the blood flow and nutrients into the fetal baby and affecting the development of the fetal baby. The mother-to-be has smoking, alcohol and other bad behaviors. If the mother-to-be has smoking, alcohol and other bad behaviors, or if the mother-to-be has abnormal uterine development, so that the fetal baby does not have enough space to grow, or if the mother-to-be has been exposed to toxic and harmful substances, it will also affect the development of the fetal baby. During pregnancy, smoking and alcohol must be banned, and good habits are what the mother-to-be should try to achieve. 3.What should I do if the fetal growth is restricted? If the fetal growth is found to be restricted, the mother-to-be must remedy it in time. There are limited prenatal treatments for fetal growth restriction, so the main thing for patients is to clarify the cause, focus on monitoring and timely delivery. Therefore, all mothers-to-be should have regular maternity checkups and ultrasound examinations during pregnancy to detect abnormalities and treat them as early as possible. The current treatment options are: Basic treatment Basic treatment includes bed rest and nutritional supplementation: bed rest: left side lying is recommended to normalize renal blood flow and renal function, thus improving the blood supply to the uteroplacenta and improving the nutritional supply status of the fetus in utero. Supplementation: theoretically amino acids are the main source of fetal protein synthesis, the material basis for fetal growth and development, reaching the fetus by active transport through the placenta; energy synergists contribute to the active transport of amino acids; glucose is the source of fetal calories and facilitates fetal growth. Therefore, we often give nutrients intravenously to supplement amino acids, energy compounds and glucose to mothers-to-be. Medication Use medications as appropriate, such as magnesium sulfate to restore normal blood perfusion to the placenta. Danshen can promote cell metabolism, improve microcirculation, reduce capillary permeability, and help maintain placental function. Low-molecular heparin and aspirin for antiphospholipid antibody syndrome are effective for FGR. Obstetric management Indications for continued pregnancy: If the fetal baby is in good condition, the placenta is functioning normally, the pregnancy is not full term, and the mother-to-be has no comorbidities or complications, the pregnancy can be carried to full term under close supervision, but should not exceed the expected delivery date.