Antenatal Screening

Antenatal Screening

The screening process can make use of blood tests (to test for antibodies and hemoglobin levels), an ultrasound (to test for structural abnormalities in the fetus), and a urine test (to test for possible infections).

  • At 9-12 weeks chorionic villus sampling may be necessary to diagnose chromosomal anomalies.

  • At 11-13 weeks a blood test is taken to examine biochemical markers (PAPP-A and free B-HCG) that can detect fetal chromosomal anomalies (such as Down's Syndrome).

  • At 11-13 weeks pelvic ultrasound is done to measure fetal nuchal translucency and the presence of the fetal nasal bone, for early detection of chromosomal anomalies (such as Down's Syndrome).

  • At 14-16 weeks if necessary, amniocentesis is performed if either of the above tests are inconclusive or doubtful.

  • At 20-22 weeks a 3D or 4D ultrasound is advised to detect structural and anatomical fetal anomalies (for example, Down's Syndrome, neural tube defects, facial and limb anomalies).