The biparietal diameter and femoral head of Down’s babies usually match the gestational week. Down’s babies have chromosomal abnormalities and normal development of biparietal diameter and femoral head.
Down’s babies are due to chromosomal abnormalities, resulting in a fetus with a special face and a low level of mental development and inability to take care of itself. However, all other aspects of development are the same as a normal fetus, so the biparietal diameter and femoral head of the fetus will develop normally, in line with the gestational week.
Down’s syndrome screening is recommended at 16 to 18 weeks of pregnancy. If the screening shows a moderate to high risk, it is also necessary to confirm whether the fetus is a Down’s baby, and further testing by amniocentesis is recommended. If the results of the test are abnormal, prompt medical attention is needed for treatment.