Learning Objectives and CME/Disclosure Information

Original Launch Date: 12/27/2022

Expiration Date: 12/27/2024

ACCME PARS: 109640

This activity is intended for healthcare providers delivering care to women and their families.

After completing this activity, the participant should be better able to:

1.
2.

Estimated time to complete activity: 0.5 hours

Faculty:

Susan J. Gross, MD, FRCSC, FACOG, FACMG President and CEO, The ObG Project

Disclosure of Financial Relationship

Postgraduate Institute for Medicine (PIM) requires faculty, planners, and others in control of educational content to disclose all their financial relationships with ineligible companies. All identified conflicts of interest (COI) are thoroughly vetted and mitigated according to PIM policy. PIM is committed to providing its learners with high quality accredited continuing education activities and related materials that promote improvements or quality in healthcare and not a specific proprietary business interest of an ineligible company.

The PIM planners and others have nothing to disclose. The OBG Project planners and others have nothing to disclose.

Faculty: Susan J. Gross, MD, receives consulting fees from Cradle Genomics.

Planners and Managers: PIM Planners have nothing to disclose

Method of Participation and Request for Credit

Participants must read the learning objectives and faculty disclosures and study the educational activity.

If you wish to receive acknowledgment for completing this activity, please complete the test and evaluation. Upon registering and successfully completing the test with a score of 100% and the activity evaluation, your certificate will be made available immediately.

Joint Accreditation Statement

In support of improving patient care, this activity has been planned and implemented by the Postgraduate Institute for Medicine and The ObG Project. Postgraduate Institute for Medicine is jointly accredited by the Accreditation Council for Continuing Medical Education (ACCME), the Accreditation Council for Pharmacy Education (ACPE), and the American Nurses Credentialing Center (ANCC), to provide continuing education for the healthcare team.

Physician Continuing Medical Education

Postgraduate Institute for Medicine designates this enduring material for a maximum of 0.5 AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Continuing Nursing Education

The maximum number of hours awarded for this Continuing Nursing Education activity is 0.5 contact hours.

Read Disclaimer & Fine Print

SUMMARY: 

ACMG has released updated guidance on noninvasive prenatal screening (NIPT). Recommendations address the role of NIPT among average risk pregnancies as well as what disorders should be included in the panel.

ACMG Recommends

• Offer NIPT as first line fetal aneuploidy screening over traditional methods for trisomy 21, 18 and 13
  • Singleton
  • Twins
• Offer NIPT for fetal sex chromosome aneuploidies (SCA) such as Turner syndrome or Klinefelter syndrome
  • Singleton

ACMG Suggests

• Offer NIPT for
  • 22q11 deletion syndrome
    • Although all CNVs are rare, 22q11 is the most common
    • See ‘Related ObG Topics’ for more information on 22q11 deletions syndrome

Note: This is a conditional recommendation and should be understood in the context that “most patients would request this and most clinicians would offer NIPT for this purpose, after a discussion about the benefits and limitations of screening and in the context of shared decision-making”

Insufficient Evidence to Recommend

• Rare autosomal trisomy (RATs)
  • Trisomies other than 13, 18, 21, X and Y and are rare eventsAre more likely to be confined only to the placenta and not in the fetus
    • Therefore, a RAT screen positive result is most likely a false positive result
    RATs of fetal origin generally lead to miscarriage
  • Screening of unknown benefit
• Genome-wide copy number variant (CNV) screening
  • NIPT can detect CNVs and therefore identify chromosomal regions where there is excess DNA (a duplication) or missing DNA (a deletion)NIPT detects CNVs of >7 megabases | Most clinically relevant CNVs were <7 megabasesFollow-up, sensitivity and specificity data are limited
  • Clinical utility has not been determined

KEY POINTS: 

• NIPT outperformed conventional screening in all studies
  • Trisomy 21 PPV 91.8%Trisomy 18 PPV 65.8%
    • PPV lower due to lower prevalence
  • Trisomy 13 PPV 37.2%
    • PPV lower due to lower prevalence
• ACMG suggests offering 22q11 deletion syndrome screening based on available evidence
• CNVs are unrelated to maternal age
• Insufficient evidence to use NIPT to screen for RATs
• Insufficient evidence to screen for other duplications/deletions but there are “families for whom NIPT for CNVs could be offered based on the pregnancy or family history”
• NIPT may identify maternal conditions such as maternal malignancies and chromosomal imbalances that conventional screening cannot

Pre and Post-Test Counseling

• Pre-test counseling should include
  • The voluntary nature of screening
  • The main disorders that can be identified with NIPT
  • Potential for incidental findings, including those of maternal origin
  • Limitations and accuracy of screening
  • Understanding that a diagnostic test will be offered for a screen positive test result
• Post-test counseling for screen negative results should include
  • A screen negative result reduces but does not eliminate the chance of an affected fetus
  • NIPT screens for a limited number of disorders and therefore does not affect the risk of all potential outcomes and conditions
• Post-test counseling for a screen positive result should include
  • A screen positive result does not confirm a diagnosis
  • The PPV of NIPT for the specific disorder
  • A general description of the condition
  • Offer diagnostic testing for confirmation either by prenatal diagnosis or by postnatal blood sampling
• Note: Both pre and post-test counseling should be performed with every sample for informed decision making

Learn More – Primary Sources:

Noninvasive prenatal screening (NIPS) for fetal chromosome abnormalities in a general-risk population: An evidence-based clinical guideline of the American College of Medical Genetics and Genomics

Systematic evidence-based review: The application of noninvasive prenatal screening using cell-free DNA in general-risk pregnancies

Related ObG Topics:

ACOG/SMFM Professional Guidance on the Role of NIPT as a First Tier Screening Test

Expert Commentary: Incidental Detection of Maternal Malignancies via Prenatal Cell Free DNA Screening

22q11.2 Deletion Syndrome – Key Clinical Highlights