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Guideline Summary
Guideline Title
Preimplantation genetic testing.
Bibliographic Source(s)
Audibert F, Wilson RD, Allen V, Blight C, Brock JA, Désilets VA, Gagnon A, Johnson JA, Langlois S, Wyatt P. Preimplantation genetic testing. J Obstet Gynaecol Can. 2009 Aug;31(8):761-7. [37 references] PubMed External Web Site Policy
Guideline Status

This is the current release of the guideline.

Scope

Disease/Condition(s)

Fetal genetic and chromosomal abnormalities

Guideline Category
Counseling
Diagnosis
Prevention
Risk Assessment
Screening
Clinical Specialty
Family Practice
Medical Genetics
Obstetrics and Gynecology
Pediatrics
Preventive Medicine
Intended Users
Advanced Practice Nurses
Nurses
Physician Assistants
Physicians
Guideline Objective(s)

To review the techniques and indications of preimplantation genetic testing, including preimplantation genetic diagnosis and screening

Target Population

Women or couples with suspected or confirmed genetic or chromosomal abnormalities or who are considering assisted reproductive technology, including the following groups:

  • Carriers of single gene disorders, dominant or recessive, autosomal, or X-linked (preimplantation genetic diagnosis)
  • Carriers of structural chromosome abnormalities, including reciprocal or Robertsonian translocations, inversions, and others (preimplantation genetic diagnosis)
  • Couples with repeated implantation failure following assisted reproduction treatments to enhance pregnancy success with transfer of normal karyotypic embryos (preimplantation genetic screening)
  • Couples with repeated unexplained miscarriages (preimplantation genetic screening)
  • Women of advanced maternal age, in order to avoid chromosomally abnormal offspring and to improve the success of in vitro fertilization procedures (preimplantation genetic screening)
Interventions and Practices Considered

Screening/Diagnosis/Counseling

  1. Genetic counseling and education prior to preimplantation genetic testing
  2. Preimplantation genetic diagnosis (PGD)
  3. Preimplantation genetic screening
  4. Invasive prenatal testing to confirm the results of PGD
Major Outcomes Considered
  • Accuracy rate of preimplantation genetic diagnosis
  • Implantation and birth rates
  • Rates of misdiagnosis
  • Miscarriage rates
  • Incidence of aneuploid syndromes

Methodology

Methods Used to Collect/Select the Evidence
Hand-searches of Published Literature (Secondary Sources)
Searches of Electronic Databases
Searches of Patient Registry Data
Searches of Unpublished Data
Description of Methods Used to Collect/Select the Evidence

The Cochrane Library and Medline were searched for articles relating to preimplantation testing that were published from 1990 to February 2008, using the following terms: preimplantation genetic diagnosis, preimplantation genetic screening, and in vitro fertilization. Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. Additional publications were identified from the bibliographies of these articles. Randomized controlled trials were considered evidence of the highest quality, followed by cohort studies.

Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment–related agencies, clinical practice guideline collections, clinical trial registries, and from national and international medical specialty societies.

Number of Source Documents

Not stated

Methods Used to Assess the Quality and Strength of the Evidence
Weighting According to a Rating Scheme (Scheme Given)
Rating Scheme for the Strength of the Evidence

Quality of Evidence Assessment*

I: Evidence obtained from at least one properly randomized controlled trial

II-1: Evidence from well-designed controlled trials without randomization

II-2: Evidence from well-designed cohort (prospective or retrospective) or case-control studies, preferably from more than one centre or research group

II-3: Evidence obtained from comparisons between times or places with or without the intervention. Dramatic results in uncontrolled experiments (such as the results of treatment with penicillin in the 1940s) could also be included in this category

III: Opinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees

*Adapted from the Evaluation of Evidence criteria described in the Canadian Task Force on Preventive Health Care

Methods Used to Analyze the Evidence
Systematic Review
Description of the Methods Used to Analyze the Evidence

Not stated

Methods Used to Formulate the Recommendations
Expert Consensus
Description of Methods Used to Formulate the Recommendations

Not stated

Rating Scheme for the Strength of the Recommendations

Classification of Recommendations

A. There is good evidence to recommend the clinical preventive action

B. There is fair evidence to recommend the clinical preventive action

C. The existing evidence is conflicting and does not allow to make a recommendation for or against use of the clinical preventive action; however, other factors may influence decision-making

D. There is fair evidence to recommend against the clinical preventive action

E. There is good evidence to recommend against the clinical preventive action

L. There is insufficient evidence (in quantity or quality) to make a recommendation; however, other factors may influence decision-making

†Adapted from the Classification of Recommendations criteria described in the Canadian Task Force on Preventive Health Care

Cost Analysis

A formal cost analysis was not performed and published cost analyses were not reviewed.

Method of Guideline Validation
Internal Peer Review
Description of Method of Guideline Validation

This technical update has been prepared by the Genetics Committee and reviewed and approved by the Executive of the Society of Obstetricians and Gynaecologists of Canada.

Recommendations

Major Recommendations

The quality of evidence (I–III) and classification of recommendations (A–E, L) are defined at the end of the "Major Recommendations" field.

  1. Before preimplantation genetic diagnosis is performed, genetic counselling must be provided to ensure that patients fully understand the risk of having an affected child, the impact of the disease on an affected child, and the benefits and limitations of all available options for preimplantation and prenatal diagnosis. (III-A)
  2. Couples should be informed that preimplantation genetic diagnosis can reduce the risk of conceiving a child with a genetic abnormality carried by one or both parents if that abnormality can be identified with tests performed on a single cell. (II-2B)
  3. Invasive prenatal testing to confirm the results of preimplantation genetic diagnosis is encouraged because the methods used for preimplantation genetic diagnosis have technical limitations that include the possibility of a false negative result. (II-2B)
  4. Before preimplantation genetic screening is performed, thorough education and counselling must be provided to ensure that patients fully understand the limitations of the technique, the risk of error, and the lack of evidence that preimplantation genetic screening improves live-birth rates. (III-A)
  5. Available evidence does not support the use of preimplantation genetic screening as currently performed to improve live-birth rates in patients with advanced maternal age, recurrent implantation failure, or recurrent pregnancy loss. (I-D)

Definitions:

Quality of Evidence Assessment*

I: Evidence obtained from at least one properly randomized controlled trial

II-1: Evidence from well-designed controlled trials without randomization

II-2: Evidence from well-designed cohort (prospective or retrospective) or case-control studies, preferably from more than one centre or research group

II-3: Evidence obtained from comparisons between times or places with or without the intervention. Dramatic results in uncontrolled experiments (such as the results of treatment with penicillin in the 1940s) could also be included in this category

III: Opinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees

Classification of Recommendations

A. There is good evidence to recommend the clinical preventive action

B. There is fair evidence to recommend the clinical preventive action

C. The existing evidence is conflicting and does not allow to make a recommendation for or against use of the clinical preventive action; however, other factors may influence decision-making

D. There is fair evidence to recommend against the clinical preventive action

E. There is good evidence to recommend against the clinical preventive action

L. There is insufficient evidence (in quantity or quality) to make a recommendation; however, other factors may influence decision-making

*Adapted from the Evaluation of Evidence criteria described in the Canadian Task Force on Preventive Health Care

†Adapted from the Classification of Recommendations criteria described in the Canadian Task Force on Preventive Health Care

Clinical Algorithm(s)

None provided

Evidence Supporting the Recommendations

Type of Evidence Supporting the Recommendations

The type of supporting evidence is identified and graded for each recommendation (see "Major Recommendations").

Benefits/Harms of Implementing the Guideline Recommendations

Potential Benefits
  • Preimplantation genetic diagnosis is an alternative to prenatal diagnosis for the detection of genetic disorders in couples at risk of transmitting a genetic condition to their offspring.
  • Preimplantation genetic screening has been proposed to improve the effectiveness of in vitro fertilization in women of advanced maternal age or in couples with recurrent miscarriage or implantation failure, but the benefits of this approach are debated.
Potential Harms
  • The risks associated with assisted reproductive technologies
  • The risks associated with embryo biopsy and extended culture
  • The technical limitations and pitfalls of preimplantation genetic diagnosis (PGD), including the risk for misdiagnosis and the need for subsequent prenatal diagnostic testing via chorionic villus sampling or amniocentesis to confirm the results obtained with PGD
  • The risks associated with chorionic villus sampling, amniocentesis, ultrasonography with or without additional blood tests, and no prenatal testing
  • The possibility that no embryos may be transferred if all are affected and the possibility that unaffected embryos that carry the recessive or X-linked disorder may be transferred

Qualifying Statements

Qualifying Statements

This document reflects emerging clinical and scientific advances on the date issued and is subject to change. The information should not be construed as dictating an exclusive course of treatment or procedure to be followed. Local institutions can dictate amendments to these opinions. They should be well documented if modified at the local level. None of these contents may be reproduced in any form without prior written permission of the Society of Obstetricians and Gynaecologists of Canada (SOGC).

Implementation of the Guideline

Description of Implementation Strategy

An implementation strategy was not provided.

Implementation Tools
Foreign Language Translations
For information about availability, see the Availability of Companion Documents and Patient Resources fields below.

Institute of Medicine (IOM) National Healthcare Quality Report Categories

IOM Care Need
Living with Illness
Staying Healthy
IOM Domain
Effectiveness
Patient-centeredness

Identifying Information and Availability

Bibliographic Source(s)
Audibert F, Wilson RD, Allen V, Blight C, Brock JA, Désilets VA, Gagnon A, Johnson JA, Langlois S, Wyatt P. Preimplantation genetic testing. J Obstet Gynaecol Can. 2009 Aug;31(8):761-7. [37 references] PubMed External Web Site Policy
Adaptation

Not applicable: The guideline was not adapted from another source.

Date Released
2009 Aug
Guideline Developer(s)
Society of Obstetricians and Gynaecologists of Canada - Medical Specialty Society
Source(s) of Funding

Society of Obstetricians and Gynaecologists of Canada

Guideline Committee

Genetics Committee

Composition of Group That Authored the Guideline

Principal Author: François Audibert, MD, Montreal QC

Committee Members: R. Douglas Wilson (Chair), MD, Calgary AB; Victoria Allen, MD, Halifax NS; François Audibert, MD, Montreal QC; Claire Blight, RN, Dartmouth NS; Jo-Ann Brock, MD, Halifax NS; Valérie Anne Désilets, MD, Montreal QC; Alain Gagnon, MD, Vancouver BC; Jo-Ann Johnson, MD, Calgary AB; Sylvie Langlois, MD, Vancouver BC; Phil Wyatt, MD, Toronto ON

Financial Disclosures/Conflicts of Interest

Disclosure statements have been received from all members of the committee.

Guideline Status

This is the current release of the guideline.

Guideline Availability

Electronic copies: Available in Portable Document Format (PDF) from the Society of Obstetricians and Gynaecologists of Canada (SOGC) Web site External Web Site Policy. Also available in French from the SOGC Web site External Web Site Policy.

Print copies: Available from the Society of Obstetricians and Gynaecologists of Canada, La société des obstétriciens et gynécologues du Canada (SOGC) 780 promenade Echo Drive Ottawa, ON K1S 5R7 (Canada); Phone: 1-800-561-2416

Availability of Companion Documents

None available

Patient Resources

None available

NGC Status

This NGC summary was completed by ECRI Institute on April 2, 2010.

Copyright Statement

This NGC summary is based on the original guideline, which is subject to the guideline developer's copyright restrictions.

Disclaimer

NGC Disclaimer

The National Guideline Clearinghouse™ (NGC) does not develop, produce, approve, or endorse the guidelines represented on this site.

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