Prenatal Genetic Testing for Chromosomal Anomalies By: Linda DeFranco.

Presentation on theme: "Prenatal Genetic Testing for Chromosomal Anomalies By: Linda DeFranco."— Presentation transcript:

1 Prenatal Genetic Testing for Chromosomal Anomalies By: Linda DeFranco

2 Text  Purpose-to educate pregnant women about available genetic testing-including screenings and diagnostic testing  Audience-pregnant women in an obstetrical practice at the time of their initial visit-approximately at 8-9 weeks of pregnancy  Goals-to fully inform a pregnant women of options that are available to her for detected chromosomal abnormalities including Trisomy 13 and 18, Downs Syndrome and ONTD and other fetal chromosome abnormalities

3 Prenatal genetic testing Screening Non-invasive First trimester ultra screen Sequential or Quad Screen NIPT (non- invasive prenatal testing) Diagnostic invasive Amniocentesis CVS (chorionic villi sampling) OVERVIEW OF PRENATAL GENETIC TESTING

4 There are different prenatal tests available to pregnant women: Screening tests vs Diagnostic testing: SCREENING TESTS: First trimester screen (known as an ultra screen) -11 to 13.6 weeks of pregnancy with sonogram Sequential screen-is a blood test that is combined with the first trimester screen results -done at 16 and 21 weeks of pregnancy

5 Benefits of Prenatal Screening First trimester ultra screen and Sequential -non-invasive -no risk of pregnancy loss Limitations: -not all pregnancies with trisomy 13, 18 and Downs syndrome are detected. -a false positive rate of <3% -limited to the amount of chromosome abnormalities detected

6 NIPS Testing NIPS (non-invasive prenatal screening) -as early as 10 weeks gestation -tests fetal DNA in maternal blood -mom has to be 35 years old at delivery (to be covered by insurance) -known as Materniti 21, Verifi, Harmony, Natera Benefits -Detection rate is 99% for Downs Syndrome and Trisomy 18; and 90% for Trisomy 13 -Low false positive rate of <1% for all Limitations -a positive result needs to be followed up with an amnio or CVS -used only for singleton pregnancies

7 Diagnostic testing- Invasive procedures CVS (chorionic villi sampling) -done between 10-12 weeks -2 different methods: transcervical and transabdominal -risk for pregnancy loss=1/300 Amniocentesis (ultrasound guided) -done at 15-18 weeks Risk for pregnancy loss 1/400

8 Benefits of Amniocentesis and CVS: -looks directly at chromosomes -can be done with twins -CVS can be done as early as 10 weeks gestation -99.9% accurate Limitations and Risks of Amniocentesis and CVS: -miscarriage -infection -bleeding -leaking of amniotic fluid -with CVS more cells are required Future of Prenatal Genetic Testing

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10 QUESTION What testing method is the best option for a 35 year old pregnant woman with no family history of genetic abnormalities? A.Amniocentesis B. CVS C. Sequential screen D. NIPS

11 References http://minnesota.cbslocal.com/2013/06/09/prenatal-tests-detect- gender-disorders-in-fetusus-early/http://minnesota.cbslocal.com/2013/06/09/prenatal-tests-detect- http://rap.northshorelij.com/contents/,DanaInfo=www.uptodate.com+ first-trimester-combi...retrievedhttp://rap.northshorelij.com/contents/,DanaInfo=www.uptodate.com+ first-trimester-combi...retrieved 3/6/14. http://www.nytimes.com/2012/08/09/health/research/clinical-trial- http://www.nytimes.com/2012/08/09/health/research/clinical-trial- yields-positive-results-for-new-prenatal-test.html?_r=0 https://www.youtube.com/watch?v=-nc9J4X6V4Y North Shore-LI Jewish Medical Center-Division of Medical Genetics (2013), Manhasset, NY. http://www.medscape.com/viewarticle/813882#2.com/viewarticle/813882#2