Advances in genetic testing and screening have resulted in many new tests to provide women with information about the health of the fetus before birth. Many of these tests are time sensitive - new tests for prenatal screening for Down syndrome, for example, are available at 11 weeks’ gestation.
We have developed several resources to help health care providers learn about these new prenatal screening tests for Down syndrome and to help women and their families make informed decisions about prenatal screening.
Prenatal Screening for the Detection of Down Syndrome, Trisomy 18, and Open Neural Tube Defects
(This monograph includes information about Down syndrome, trisomy 18 and open neural tube defects, prenatal screening tests including testing algorithms, detection and false positive rates, diagnostic testing options, and a table of risk of chromosome abnormalities with maternal age.
This PowerPoint module was written to help educate health care providers about the new screening tests available for Down syndrome; it can be used as a reference or for the education of other health care professionals.
Society of Obstetricians and Gynaecologists of Canada – SOGC Clinical Practice Guidelines: Prenatal Screening for Fetal Aneuploidy. JOGC 2007; 187 146-161.
A Guide to Understanding Prenatal Screening Tests for Women and their Families En français (This guide includes information about the disorders screened for, description of testing options & results, things to consider before deciding about prenatal screening, and diagnostic testing.
Genetic Screening Tips: Pre-conception and During Pregnancy
Family history (3 generations): consider referral to genetics in the following circumstances:
- Family history of:
- birth defects
- mental retardation or developmental delay
- stillbirths or childhood deaths
- chromosome disorders
- severe childhood conditions (muscular dystrophy, cystic fibrosis)
- Potential patterns of inheritance
Consider referral to genetics with the following pregnancy history:
- maternal age ≥35
- 3 or more spontaneous abortions
- childhood deaths
For more information see:
- Society of Obstetricians and Gynaecologists of Canada - SOGC Clinical Practice Guidelines: Canadian Guidelines for Prenatal Diagnosis (pdf ). JOGC 2001; 105 1-7.
The Ashkenazi Jewish screening panel at the Hospital for Sick Children currently consists of testing for seven diseases common in the Ashkenazi Jewish population:
- Bloom syndrome
- Canavan disease
- Familial dysautonomia
- Fanconi anemia group C
- mucolipidosis type IV
- Niemann Pick disease type A & B
- Tay-Sachs disease
For more information see:
- The Hospital for Sick Children, Molecular Genetics Laboratory, Ashkenazi Jewish screening panel website
- Society of Obstetricians and Gynaecologists of Canada – SOGC Clinical Practice Guidelines: Carrier Screening in Individuals of Ashkenazi Jewish Descent (pdf ). JOGC 2006; 177:324-332
Hemoglobinopathies are a group of genetic conditions affecting red blood cells in people with the following backgrounds:
- Middle Eastern
- Hispanic/South/Central American background
For more information see:
- Society of Obstetricians and Gynaecologists of Canada – SOGC Clinical Practice Guidelines: Canadian Guidelines for Prenatal Diagnosis (pdf ). JOGC 2001; 105 1-7.
For a list of genetics clinics located in Canada, see the Canadian Association of Genetic Counsellors’ website If you have questions about the management of a patient with one of the above risk factors, contact your local genetics clinic for assistance.
- Mount Sinai Hospital, Prenatal Diagnosis and Medical Genetics Clinic website
You will find information about: Genetic counseling, nuchal translucency/early anatomy ultrasound, prenatal screening tests, first trimester combined screening (FTS), integrated prenatal screening (IPS), maternal serum screen (MSS or triple screening), ultrasound, amniocentesis, chorionic villus sampling (CVS), basic genetics information.
- March of Dimes: For professionals
See “Genetics & Your Practice”: Online continuing education program in genetics for physicians, specialists, nurses and midwives.
- March of Dimes: For patients
An excellent source of patient information for questions during pregnancy, such as pre-conception, common prenatal tests, complications, things to avoid, birth defects and more.
A teratogen information service.
- Ontario Provincial Multiple Marker Screening (MMS) Program
Patient information on IPS, FTS and second trimester MSS.
- OTIS: Organization of Teratology Information Specialists
A teratogen information service, website has patient information sheets for a variety of common exposures during pregnancy in English, French and Spanish.
See Genetics section and Genetic Counsellor’s toolbox section. A clearing house of obstetrical resources: links to information regarding treatment of various maternal conditions & teratogen exposures during pregnancy; professional organizations, treatment guidelines & journal articles.
- Canadian Association of Genetic Counsellors
List of medical genetic centres located across Canada.
- Canadian Down Syndrome Society
More information about Down syndrome with links to parent support groups.
- The Genetics Home Reference Your Guide to Understanding Genetic Conditions
An excellent genetics education site.
- S.O.F.T. Support Organization For Trisomy 18, 13 and Related Disorders
More information about trisomy 18.
- Spina Bifida and Hydrocephalus Association of Canada
More information about spina bifida.