When is the best time to perform the NT scan?
Disease description:
My younger aunt is pregnant. She read online that she should undergo an NT scan, which is a very important prenatal screening test for detecting whether the fetus is developing normally. When is the best time to have the NT scan?
Doctor's answer (1)
Dr. Zhao Xiaodong
The optimal time for the NT scan is between 11 weeks and 13 weeks plus 6 days of pregnancy, which is considered the best window period for conducting the NT examination.
1. Pregnant women with regular menstrual cycles: For pregnant women with normal menstrual cycles (usually 28-30 days), it is recommended to undergo the NT scan between 11 weeks and 13 weeks plus 6 days of gestation. During this period, the thickness of the fetal nuchal translucency can be clearly and accurately measured, thereby assessing the risk of fetal chromosomal abnormalities or structural malformations.
2. Pregnant women with irregular menstrual cycles: If a pregnant woman has an irregular menstrual cycle, the timing for the NT scan can be determined based on the fetal crown-rump length (CRL). When the CRL is between 46-84 mm, it is also an appropriate time for performing the NT scan.
The NT scan is only a method for early screening of fetal abnormalities. If the results are abnormal, further diagnostic tests are required for confirmation.
