The first ultrasound examination is usually performed in the 6th week of pregnancy, in order to ascertain the presence and position of the fetus (intrauterine – ectopic), the number of embryos, the normal development of pregnancy particularly in cases of bleeding and severe abdominal pain and the presence of heartbeats in the fetus etc., in order to permit timely interventions.
Later, between the 11th and 14th week of pregnancy, a very important ultrasound examination is performed, which measures the nuchal translucency-NT (amount of fluid in the neck) of the fetus, providing invaluable information regarding the presence of possible chromosomal abnormalities (especially for Down syndrome). It also accurately determines the week of pregnancy, especially in those cases where we are unsure of the exact date of the last menstrual period, and to detect several fetal structural malformations, such as anencephaly, omphalocele, etc..
This ultrasound also monitors the existence of the nasal bone, the fetal stomach and bladder, as well as the formation of the upper and lower extremities and of the fetal skull. In parallel, using the Doppler technique, we monitor the blood flow (ductus venosus and tricupsid valve). In this way we can assess proper placentation, i.e. the correct development of the embryo-placental circulation.
Finally, at the same time we draw a maternal blood sample, for the measurement of the circulating biochemical markers free-βhCG and PAPP-a, which in combination with the NT value, will provide a statistical risk evaluation mainly for Down syndrome (prenatal biochemical marker testing).