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Updated: May 31, 2026
09:03
Semiconductor Sequencing for Preimplantation Genetic Testing for Aneuploidy
Published on: August 25, 2019
Prenatal screening for fetal aneuploidy in singleton pregnancies
David Chitayat1, Sylvie Langlois2, R Douglas Wilson3
1Toronto ON.
Journal of Obstetrics and Gynaecology Canada : JOGC = Journal D'Obstetrique Et Gynecologie Du Canada : JOGC
|July 14, 2011
Summary
Canadian guidelines recommend offering non-invasive prenatal screening for fetal aneuploidy to all pregnant women. This approach aims to reduce invasive procedures and associated risks, improving outcomes for common chromosomal abnormalities like Down syndrome.
Area of Science:
- Maternal-Fetal Medicine
- Prenatal Diagnostics
- Genetics
Background:
- Historically, maternal age was the primary screening method for fetal aneuploidy.
- Advancements in serum and ultrasound technologies enable non-invasive risk assessment for fetal aneuploidies (e.g., Down syndrome, trisomy 18, trisomy 13).
- Non-invasive screening determines the necessity for invasive prenatal diagnostic testing.
Purpose of the Study:
- To establish a Canadian consensus on maternal screening for fetal aneuploidy in singleton pregnancies.
- To review available non-invasive screening options.
- To provide recommendations for Canadian patients and healthcare providers.
Main Methods:
- Systematic literature search of studies published between 1982 and 2009 (updated to August 2010) from databases including PubMed, Medline, CINAHL, and Cochrane Library.
- Inclusion of systematic reviews, randomized controlled trials, and observational studies; no language restrictions.
- Inclusion of grey literature and review of previous Canadian guidelines on prenatal screening.
Main Results:
- All pregnant women should be offered non-invasive screening for fetal aneuploidies (trisomy 13, 18, 21) alongside routine second-trimester ultrasound.
- Invasive diagnostic testing is recommended for women with elevated screening risk or specific personal/family history factors.
- Available non-invasive options include first-trimester screening, second-trimester serum screening, and integrated/sequential screening approaches.
Conclusions:
- Maternal age alone is insufficient for recommending invasive testing when non-invasive screening is available.
- The guideline aims to decrease unnecessary invasive procedures, thereby reducing the loss of normal pregnancies.
- Implementation requires informed counseling, standardized screening performance (e.g., 75% detection rate), quality assurance, and adequate resources.
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