It is normal for the NT fetal heart rate to be 161 beats per minute for a short period of time because the fetal heart rate fluctuates and is not constant. The normal fetal heart rate fluctuates between 110 and 160 beats/min, and it is normal to have a heart rate greater than 160 beats/min for a short period of time. The fetal heart rate may increase due to excessive fetal activity in the uterus or external stimulation of the fetus. The NT test is done before 13 weeks to detect any abnormalities in fetal development, especially those caused by genetic factors, such as chromosomal abnormalities. It is necessary to have regular prenatal checkups to prevent the birth of abnormal fetuses and improve eugenics. Pay attention to strengthen the nutritional intake, more rest, avoid staying up late, tired.