How much does the full-term fetus weigh? The birth weight of normal full-term newborns is between 2500 grams and 4000 grams. The average weight of normal full-term newborns is 3300g, and the average height of normal full-term newborns is 50cm. More than 4000 grams is macrosomia, and less than 2500 grams is low birth weight. Newborns above 4000 grams and less than 2500 grams may have high risk factors.
1. Normal term infants
Normal term infants refer to newborns whose gestational age is more than 37 weeks and less than 42 weeks (259-293 days). The birth weight of full-term newborns ranges from 2500 to 4000 grams, with an average of 3200 grams. The height is more than 46 cm, with an average of about 50 cm. External features: clear wool tops, well-developed cartilage in the ear shell, palpable nodules in the breast, nails reaching or exceeding the fingertips, more texture on the soles of the feet, countless wrinkles in the scrotum of the baby boy, and testicles descending into the scrotum. The baby girl's labia majora has covered the labia minora.
2. Giant baby
The birth weight is more than 4,000 grams, and some of them are normal and healthy children, which may be related to heredity and excessive intake during pregnancy. Some of them have high risk factors, such as maternal diabetes during pregnancy, fetal Rh hemolysis, congenital heart disease (great vascular dislocation) and so on. Macrosomia is prone to asphyxia and intracranial hemorrhage during delivery. Because the fetus is too big, it is prone to dystocia and birth injury. The macrosomia whose mother has diabetes is prone to hypoglycemia, which affects brain development, and can also lead to erythrocytosis, high blood viscosity, intravascular coagulation and venous embolism.
Therefore, it is necessary to have reasonable nutrition during pregnancy and avoid excessive intake of protein and starchy foods. Pregnant women with diabetes need timely treatment and diet control to ensure the necessary nutrition of mother and baby, maintain normal blood sugar level and maintain normal weight gain. Early screening of maternal blood type and blood sugar and regular screening of fetal malformation can avoid the occurrence of macrosomia.
3. Low birth weight infants
Newborns with a birth weight of less than 2500 grams are called low birth weight infants. These include premature babies and full-term babies, full-term babies, weighing below 2500 grams.
Full-term babies can be caused by a variety of reasons: ① Mother: It can be caused by insufficient nutrition of pregnant mothers, which leads to fetal malnutrition. Others, such as pregnant women with serious diseases (such as fever, hypertension, kidney disease, uterine malformation, etc. Fetus: Virus infection during pregnancy can invade placenta, damage blood vessels, affect fetal growth and development or cause fetal congenital malformation. ③ Placenta and umbilical cord: Due to the abnormal structure of placenta and umbilical cord, fetal blood flow is insufficient, which affects nutrition and oxygen supply.
Mothers should pay attention to nutrition during pregnancy, avoid contact with harmful poisons and reduce diseases. Timely prenatal examination, active prevention and treatment of pregnancy diseases, and regular B-ultrasound detection of fetal growth and development can achieve early diagnosis and early intervention.
Full-term fetal biparietal diameter If the standard of biparietal diameter is above 8.8, full-term infants are now considered normal. According to the size of the baby, the biparietal diameter is generally within 10.0, and some will exceed 10.0.
Double crown diameter is also called BPD, and double crown diameter of fetal head. Refers to the length of the widest part between the left and right sides of the fetal head, also known as the "large transverse diameter of the head". Doctors often use it to observe the child's development and judge whether there is an imbalance between the head and pelvis and a natural delivery.
The biparietal diameter of the fetus should reach 9.3 cm or more at full term. According to the general rule, after 5 months of pregnancy, it basically coincides with the month of pregnancy, that is, the BPD of 28 weeks (7 months) is about 7.0 cm, and that of 32 weeks (8 months) is about 8.0 cm, and so on. After 8 months of pregnancy, it is normal to grow about 0.2 cm per week on average. When the expected delivery date cannot be determined by CRL in the early stage, BPD is often used for forecasting; After the middle period, it is often necessary to measure these data when estimating fetal weight.
Experts remind: it is not scientific enough to see whether the fetus is male or female with double top diameter. But the fetal weight is calculated by biparietal diameter examination, and the formula is: fetal weight = biparietal diameter *900-5200 (g).
Femoral length (FL) is a commonly used index for doctors to observe fetal development when using B-ultrasound (or color ultrasound) to examine pregnant women during pregnancy.
Femur and humerus are both typical long tubular bones in human body, which are divided into two ends. The femur is the largest long bone in the human body, which refers to the thigh bone; The humerus is located in the upper arm, also known as the upper arm bone. So as the name implies, the length of femur is the length of femur, and the length of humerus is the length of upper arm bone.
Femoral length and humeral length are both fetal biological indexes to predict fetal weight. However, fetal humeral length is superior to femoral length in predicting fetal weight.