Femur length refers to the length of the thigh bone, which is an important indicator during pregnancy. Doctors can determine whether the fetus is developing normally based on the fetal femur length data in ultrasound data. So, what does femur length mean? What is the standard femur length? AC – abdominal circumference APTD – the thickness of the anterior-posterior abdomen, also known as the anterior-posterior abdominal diameter. This measurement is needed to check the development of the fetal abdomen and to determine the weight of the fetus. BDP — Biparietal diameter The length of the longest part of the head between the right and left sides, also known as the “greater transverse head diameter”. BPD is often used to predict the due date when the CRL is not available in the early stages of labor, and is often needed to determine the weight of the fetus after the midterm stage. CRL — head-rump length is the head-rump distance, which is the longest axis measured parallel to the longitudinal axis of the fetal body and is mainly used to determine the gestational age at 7-12 weeks of gestation. HC — Head circumference FL — Femoral length The length of the fetal thigh bone, also known as the “thigh bone length”. The thigh bone is the length of the thigh from the root of the thigh to the knee. The FL is usually measured around 20 weeks of gestation to check the development of the fetus. GS – fetal sac In women with regular menstruation, the gestational sac can be seen in the uterine cavity by ultrasound at 35 days of menopause. The gestational sac is about 2 cm in diameter at 1.5 months of pregnancy and about 5 cm at 2.5 months. The location of the sac in the fundus, anterior wall, posterior wall, upper part and middle part of the uterus is normal; round, oval and clear shape is normal; if the sac is irregularly shaped, blurred and located in the lower part of the uterus and the pregnant woman has abdominal pain or vaginal bleeding at the same time, she may have to miscarry. HL – humeral length TTD – the width of the abdomen, also known as the “transverse abdominal diameter”. It is taken after 20 weeks of gestation, along with the APTD, to check the development of the fetus. Sometimes the area of the abdomen is also measured GP – placenta grading, generally the placenta is graded into 0, I, II, III and sometimes III+ AFI – amniotic fluid index, during the ultrasound, the umbilicus of the pregnant woman is the center, divided into 4 areas: upper, lower, left and right. The normal value of amniotic fluid index in late pregnancy is 8~18 (24) cm. S/D – the ratio of fetal umbilical artery systolic pressure to diastolic pressure, related to fetal blood supply, this ratio will be abnormal when the placenta is malfunctioning or the umbilical cord is abnormal, in normal pregnancy, with the increase of fetal needs with the increase of gestational weeks S decreases and D increases, so that the ratio decreases, near full-term pregnancy S/D is less than 3. 4 weeks of pregnancy: the fetus is only 0.2 cm. The fertilized egg has just completed its implantation and the amniotic cavity has only just formed and is very small. The ultrasound does not yet show any signs of pregnancy. The fetus is 0.4 cm long and has entered the embryonic stage, the amniotic cavity is enlarged, the primitive cardiovascular vessels are present and may be pulsating, a small fetal sac can be seen on ultrasound, which occupies less than 1/4 of the uterine cavity or a fetal bud can be seen. 6 weeks of gestation: the fetus grows to 0.85 cm, the fetal head, brain vesicles, frontal organs, respiratory, digestive and neurological organs are differentiated, the fetal sac is clearly visible on ultrasound, and the fetal bud and fetal heartbeat can be seen. At 7 weeks of gestation, the fetus is 1.33 cm long, the embryo is already in human form, all the body segments are differentiated, the limbs are separated, and all the systems are further developed. At 8 weeks of gestation, the fetus is 1.66 cm long, the fetal shape is fixed, the fetal head, body and limbs can be separated, the fetal head is larger than the trunk, the fetal sac can be seen at ultrasound, the fetal shape and fetal movement can be clearly seen. The fetus is clearly visible, and the yolk sac can be seen. The fetal head is larger than the fetal body and the various parts of the fetus are clearer, the head starts to calcify and the placenta starts to develop. At 10 weeks of gestation, the fetus is 2.83 cm long, all the fetal organs are formed and the placenta is taking shape; the ultrasound shows that the fetal sac is beginning to disappear, the placenta is visible in the shape of a moon bud and the fetus is active in the amniotic fluid. 11 weeks of gestation: the fetus grows to 3.62 cm, the fetal organs are further developed and the placenta is developing. the ultrasound shows that the fetal sac has completely disappeared and the placenta is clearly visible. 12 weeks of gestation: the fetus grows to 4.58 cm, the external genitalia are initially developed, if there are deformities can be shown, the cranial calcification is more perfect. The cranial halo is clear, the biparietal diameter can be measured, obvious malformations can be diagnosed, after that the organs tend to be perfect. The size of the developing fetus is judged by ultrasound during pregnancy is one of the more informative methods. Pregnant women will see some values on the examination report when they do ultrasound, and these values are the ones that tell you the size of the developing baby. To read these numbers, you need to read the following article carefully. 13 weeks of pregnancy: the average value of the biparietal diameter is 2.52 and 0.25, the average value of the abdominal circumference is 6.90 and 1.65, and the femur length is 1.17 and 0.31. 14 weeks of pregnancy: the average value of the biparietal diameter is 2.83 and 0.57, the average value of the abdominal circumference is 7.77 and 1.82, and the femur length is 1.38 and 0.48. 15 weeks of pregnancy: the average value of the biparietal diameter is 3.23 and 0.51. The mean value of the abdominal circumference was 9.13 and 1.56, and the femur length was 1.74 and 0.58. 16 weeks of gestation: the mean value of the biparietal diameter was 3.62 and 0.58, and the mean value of the abdominal circumference was 10.32 and 1.92, and the femur length was 2.10 and 0.51. 17 weeks of gestation: the mean value of the biparietal diameter was 3.97 and 0.44, and the mean value of the abdominal circumference was 11.49 and 1.62, and the femur length was 2.52 and 0.51. At 18 weeks of gestation, the mean biparietal diameter was 4.25 and 0.53, and the mean abdominal circumference was 12.41 and 1.89, with a femoral length of 2.71 and 0.46. At 19 weeks of gestation, the mean biparietal diameter was 4.52 and 0.53, and the mean abdominal circumference was 13.59 and 2.30, with a femoral length of 3.03 and 0.50. The mean value of the biparietal diameter was 4.88’0.58′, the mean value of the abdominal circumference was 14.80’l.89′ and the femur length was 3.35’O.47. 21 weeks of gestation: the mean value of the biparietal diameter was 5.22’0.42′, the mean value of the abdominal circumference was 15.62’1.84′ and the femur length was 3.64’0.40. 22 weeks of gestation: the mean value of the biparietal diameter was 5.45’0.57′ and the mean value of the abdominal circumference was 16.70’2.50. At 23 weeks of gestation: the mean value of biparietal diameter was 5.80s 0.44′ and the mean value of abdominal circumference was 17.90s 1.85′ with femur length of 4.21s 0.41. At 24 weeks of gestation: the mean value of biparietal diameter was 6.05s 0.50′ and the mean value of abdominal circumference was 18.74s 2.23′ with femur length of 4.36s 0.51. At 25 weeks of gestation: the mean biparietal diameter was 6.39’0.70′, the mean abdominal circumference was 19.64’2.20′ and the femur length was 4.65’0.42. At 26 weeks of gestation: the mean biparietal diameter was 6.68’0.61′, the mean abdominal circumference was 21.62’2.30′ and the femur length was 4.87’O.41. At 27 weeks of gestation: the mean biparietal diameter was 6.98’0.50′, the mean abdominal circumference was 18.74’2.23′ and the femur length was 4.36’0.51. The average value of the biparietal diameter is 6.98s0.57’the average value of the abdominal circumference is 21.81s2.12’the average value of the femur length is 5.10s0.41. 28 weeks of pregnancy: the average value of the biparietal diameter is 7.24sO.65’the average value of the abdominal circumference is 22.86s2.41’the average value of the femur length is 5.35s0.55. Mothers-to-be in late pregnancy must also want to know if your baby is developing normally. You must read this article and compare it carefully with the ultrasound results you have done. 29 weeks of pregnancy: the average value of the biparietal diameter is 7.50s 0.65, the average value of the abdominal circumference is 23.71s 1.50′ and the average value of the femur length is 5.61s 0.44. 30 weeks of pregnancy: the average value of the biparietal diameter is 7.83s 0.62′, the average value of the abdominal circumference is 24.88s 2.03′ and the average value of the femur length is 5.77s 0.47. 31 weeks of pregnancy: the average value of the biparietal diameter is 8.06s 0.55. 32 weeks of gestation: the mean value of biparietal diameter was 8.17 s.0.65′, the mean value of abdominal circumference was 26.20 s.2.33′ and the mean value of femur length was 6.43 s.0.49. 33 weeks of gestation: the mean value of biparietal diameter was 8.50 s.0.47′ and the mean value of abdominal circumference was 5.77 s.0.47. 0.47’The mean value of abdominal circumference was 27.78-2.30’The mean value of femur length was 6.52-0.46. 34 weeks of gestation: The mean value of biparietal diameter was 8.61-0.63’The mean value of abdominal circumference was 27.99-2.55’The mean value of femur length was 6.62-0.43. 35 weeks of gestation: The mean value of biparietal diameter was 8.70-0.55’The mean value of abdominal circumference was 28.74 At 36 weeks of gestation, the mean value of biparietal diameter was 8.81s0.57’the mean value of abdominal circumference was 29.44s2.83’and the mean value of femur length was 6.95s0.47. At 37 weeks of gestation, the mean value of biparietal diameter was 9.00s0.63’the mean value of abdominal circumference was 30.14s0.47. The mean value of femur length was 7.10 s.0.52. 38 weeks of gestation: the mean value of biparietal diameter was 9.08 s.0.59′ the mean value of abdominal circumference was 30.63 s.2.83′ the mean value of femur length was 7.20 s.0.43. 39 weeks of gestation: the mean value of biparietal diameter was 9.21 s.0.59′ the mean value of abdominal circumference was 31.34 s.3.12′ the mean value of femur length was 7.34 s.0.43. The mean value of femoral length was 7.4-0.53. The mean value of biparietal diameter was 9.28-0.50. The mean value of abdominal circumference was 31.49-2.79. The mean value of femoral length was 7.4-0.53. The fetal third ventricle was TV, cerebellum was CER, lateral ventricle was LV, anterior horn was FH, posterior horn was OH, and occipitofrontal diameter was OFD.