Screening for Chromosomal Abnormalities

Prenatal screening is to screen all pregnancies for the risk of structural and chromosomal defects that can result in Down’s, Edwards or Patau’s syndrome, referred to as Trisomies, medically. It is also to screen for a complication in pregnancy – Preeclampsia. Screening is done using both ultrasound and blood tests. If none of the structural defects and the risks are present, this implies that the pregnancy is proceeding normally.

Chromosmal-Abnormalities
FAQs
  • Prenatal screening is performed in the first trimester to assess the risk of Down’s syndrome and Preeclampsia using ultrasound as well as blood tests. In the second trimester, the risk of neural tube defect as also Preeclampsia is performed. In the third trimester, the risk of preeclampsia can be assessed and also the growth status of the developing foetus to determine if the pregnancy is proceeding normally or not.

  • Our human body contains 23 pairs of chromosomes in every cell, a total of 46 chromosomes. Many types of chromosomal abnormalities exist, but they can be categorized as either numerical or structural. Numerical abnormalities are whole chromosomes either missing from or extra to the normal pair. Structural abnormalities are when part of an individual chromosome is missing, extra, switched to another chromosome, or turned upside down. When such abnormalities are present in chromosomes it can affect the normal growth and development of the baby and it can continue in adulthood as well, causing immense distress to the baby / adult as also to the families. This Scan helps us to identify these chromosomal abnormalities in your baby. In prenatal screening, the most common chromosomal abnormalities are to screen for the risk of Down’s syndrome and preeclampsia.

  • Screening for chromosomal abnormalities is done between gestational ages of 11 to 20 weeks. It can be done using ultrasound and one of the conditions that is assessed is the thickness of the skin behind the foetus’s neck area. This gives a fairly good indication of the risks involved, requiring further investigations such as a blood screening test, non-invasive prenatal test or karyotyping from amniotic fluid.

  • An ultrasound Scan takes approximately 30 to 45 minutes sometimes even longer. Blood that is collected is sent to a lab for processing and depending on the location of the lab, test results availability, might take anywhere between 1 to 7 days.

  • You don’t have to do any special preparation before the procedure. Our experts will tell you if you need to have a full bladder for the test depending on the circumstances

  • MediScan is an acknowledged centre of excellence in Asia for fetal medicine. They have helped improve standard of care for pregnancies and have pioneered new assessment metrics and tools to determine the normalcy, safety and viability of the pregnancy. This therefore results in accuracy and reliability of its screening and diagnostic services.