Is the NT scan showing signs of Down's syndrome in fetus?

Question

Hello doctor,

My wife, aged 30 years, is 17 weeks pregnant with our second child. The prenatal (first trimester) screening report indicated a calculated risk for Down’s syndrome as 1:544 (final). NT at 12 weeks 5 days was 1.8 mm. Considering this an intermediate risk, our OBGYN advised Early Anomaly Scan during the 17th week. The findings in the ultrasound scan for soft markers came negative and the risk for Down’s was improved to 1:2837. Our OBGYN said that there is an option of NIPT available for further confirmation. But she indicated that it is only optional.

There is no history of Down’s, Edward’s, or Patau’s in both of our families. And our first child is normally active. The first child (No Down’s) was born at 33 weeks pre-term because of pre-eclampsia through LSCS. Should we get the NIPT done? Please help us because we are confused.

Answer 1

Hello,

Welcome to icliniq.com.

Considering the fact that firstly, your NT scan measured 1.8 mm which was below 2.5 mm cut off and hence was normal for gestational age. Secondly, the cut off for trisomy 21 being 1: 250 and age related risk as well were lower with 1:544 and 1: 815, so the screen was negative and there was no intermediate risk as to be considered.

The age is 30 and does not qualify for advanced maternal age and also the first baby was not a down's syndrome, hence no increased risk in present pregnancy. Thirdly the anomaly scan as well do not show any evidence of structural cardiac anomalies or endocardial cushion defects, indicating that the chances of the child being down's is way too low. NIPT with these reports is not recommended at all.