During the 12th week of pregnancy, the expectant mother must visit ultrasound examination where the doctor will determine the thickness of the child’s nuchal translucency, which is located between the soft tissues of the skin surrounding the cervical spine.

The size of this space helps to diagnose the presence of a child’s congenital chromosomal abnormalities, such as Down syndrome. Since nuchal translucency disappears after 14 weeks, it is important to evaluate it for periods ranging from 11th to 13th week, so it is better not to skip this examination.

Normally, the thickness of nuchal translucency at 12 weeks must not exceed 2.5 mm., But if it is larger this may indicate that the unborn baby may have some chromosomal abnormalities.

If there are doubts in the evaluation of fetal development after ultrasound examination doctor must send the mother-to make the biochemical analysis of a blood from a vein.

The analysis will show the presence of two markers in the body of a pregnant woman – the free b-hCG (free beta subunit of human chorionic gonadotropin) and PAPP-A (Protein A plasma associated with pregnancy).

According to the research report the expectant mother may be informed that she’s all right (because the picture on the ultrasound may not be clear enough and the measurement data therefore may be inaccurate) or directed to a geneticist, who may recommend other additional studies.