Friday, December 18, 2015

First Trimester Screening Test

We were given 2 weeks to decide on the type of Prenatal Test to do for our baby. The purpose of the test is mainly to detect early abnormalities or birth defects such as Down Syndrome. Based on my age and with no significant family medical history he advice us on the 2 common types of Non-Invasive Prenatal Testing (NIPT): One-Stop Clinic for Assessment of Risk for fetal anomalies (OSCAR) vs Harmony Prenatal Test. Accordingly to Dr Phua, the main difference between the 2 test is the cost and accuracy. OSCAR cost in the range of $300+ and has a 90% accuracy rate Harmony test cost more than $1000 and has a 99% accuracy rate And so we did our own research and found these further information:

OSCAR Test
  • Involves the NT test plus a sample of the mother’s blood which is analysed for levels of free beta hCG and PAPP-A (Pregnancy associated plasma protein A)
  • The combined data will give a risk estimate of Down syndrome with an accuracy of 90%
  • Nuchal Translucency (NT) test - detailed ultrasound scan of the baby at 11- 14 weeks of the gestation and the fluid collection behind the baby’s neck is measured.
  • A thickened NT beyond normal thickness is associated with chromosomal abnormalities such as Down’s syndrome, Edwards’s syndrome, Patau’s syndromes.
  • A risk estimate can be obtained by the result of the fetal NT value, maternal age and the crown-rump length of the fetus.
  Harmony Prenatal Test
  • Analyses cell-free DNA circulating in the pregnant mother’s blood
  • Prenatal screening for Down syndrome (trisomy 21) and other common fetal chromosomal conditions (trisomies 18 and 13).
  • Identifies more than 99% of fetuses with trisomy 21, 98% of fetuses with trisomy 18, and 80% of fetuses with trisomy 13.
  • Also evaluate sex chromosome conditions (baby gender)
  • Conducted for pregnant woman who is of a gestation of 10 weeks or more
  • Around 20ml of blood from the mother will be needed

Good reads for fellow mummy:
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