Foundations of Perinatal Genetic Counseling

Amber Mathiesen, MS, LCGC, is a licensed and board-certified genetic counselor in prenatal genetics at University of Utah Health, co-director of the perinatal genetics course at the University of Utah's Graduate Program in Genetic Counseling, and a prenatal rotation supervisor. She also acts as a research committee member and mentor for various genetic counseling students.Kali Roy, MS, LCGC, is a perinatal genetic counselor at University of Utah Health and co-director of the perinatal genetics course at the University of Utah's Graduate Program in Genetic Counseling. She graduated from the University of Utah Graduate Program in Genetic Counseling and completed a Master's of Science in Human Genetics and Genomics at the University of Connecticut.

• PrefaceAcknowledgmentsCommon Abbreviations1. Pregnancy Basics1.1 Pregnancy Timeline and DatingPregnancies are Counted in WeeksGestational Age versus Embryonic AgeNormal Pregnancy Timeline and DurationMethods for DatingGuidelines and Recommendations for Determining DatingTools Available for Calculating Gestational Age1.2 Pregnancy CareTypes of Prenatal ProvidersRoutine Prenatal VisitsPrenatal PanelComplete Blood CountBlood Type and Antibody TestingHbA1c for DiabetesFetal ImagingComplicated Pregnancies1.3 Documenting a Pregnancy HistoryGravida and ParaCalculating Gravidity and Parity (G's and P's)2. The Perinatal Genetic Counseling Appointment and Family History2.1 The Perinatal Genetic Counseling Session2.2 Obtaining a Pregnancy History2.3 Obtaining a Family History2.4 Interpreting a Family HistoryMendelian ConditionsMultifactorial ConditionsConsanguinityBirth DefectsIntellectual Disability and AutismPregnancy Loss and InfertilityUnknown EtiologiesAccuracyOther Conditions (Referrals)2.5 Unique Situations in the Perinatal Family HistoryGamete DonationSame Sex CouplesSurrogacyAdoptionEthnicity3. Prenatal Screening3.1 Evaluation of a ScreenSensitivitySpecificityPositive Predictive ValueNegative Predictive ValuePersonal Utility3.2 Prenatal Screening OptionsMaternal Serum ScreeningMultiples of the Median (MoM)Calculating the RiskTiming and Test OptionsResultsPattern AssociationFollow up of Abnormal ResultsLimitations of Maternal Serum ScreeningCell Free DNA TestingOriginFetal fractionClearanceMethodologyConditions AnalyzedTest performanceWho to offer testing to?Multiples and Vanishing TwinsAdverse Pregnancy OutcomesConsiderations Prior to TestingResults and Follow upResources4. Prenatal Diagnosis4.1 TechniquesChorionic Villus SamplingTwinsRisksLimitationsAmniocentesisTwinsRisks4.2 Testing OptionsKaryotypeFluorescence in situ Hybridization (FISH)MicroarrayMolecular TestingAFP &AChEOther Testing4.3 Indications for Diagnostic Testing5. Common Indications5.1 Age Related RisksMaternal AgePaternal Age5.2 Personal and Family HistorySingle Gene ConditionsAneuploidyMultifactorial ConditionsBirth DefectsIntellectual Disability/Developmental Delay/AutismConsanguinity5.3 Ultrasound AnomaliesCounseling for Ultrasound AnomaliesClassification of Ultrasound FindingsEstimating RisksUltrasound Findings in Pregnancies with AneuploidyDown syndromeTrisomy 18Trisomy 13Turner SyndromeTriploidyCommon Ultrasound FindingsHallmark Ultrasound Findings Associated with Genetic ConditionsOpen Neural Tube Defects5.4 Teratogens5.5 Recurrent Pregnancy Loss, Stillbirth, and InfertilityEvaluation of Pregnancy Loss and StillbirthEvaluation of InfertilityMale InfertilityFemale Infertility5.6 Preconception Counseling6. Carrier Screening6.1 BackgroundWho Should be Offered Carrier Testing?Carrier Screening for Gamete DonorsTiming of ScreeningEvaluating RisksPositive Test ResultsNegative Results and Residual RisksOther Types of ResultsApplication of a High Risk ResultRepeat TestingNewborn Screening6.2 Condition Directed or Ethnicity Based TestingCystic FibrosisSpinal Muscular AtrophyFMR1-Related DisordersAshkenazi Jewish and French Canadian/CajunHemoglobinopathiesFamily History6.3 Expanded Carrier Testing7. Pregnancy Management7.1 Reproductive OptionsContinuation of PregnancyAdoptionTerminationFirst TrimesterSecond TrimesterLater TermTwins7.2 Pregnancy Management ReferralsMaternal-Fetal Medicine SpecialistSpecialized Imaging3D UltrasoundEchocardiographyMRICardiologyNeonatologyFetal Surgery/InterventionPediatric SurgeryPediatric SpecialistsPathology/AutopsyPalliative Care/Hospice7.3 Support Referrals and Bereavement8. Assisted Reproductive Technology and Reproductive Options for the At Risk Couple8.1 Reproductive Options for At Risk Couples8.2 Assisted Reproductive Techniques8.3 Preimplantation Genetic TestingPreimplantation Genetic Screening (PGS)Preimplantation Genetic Diagnosis (PGD)9. Common Perinatal Genetic Counseling Situations9.1 Pregnancy Termination Misinterpreted IntentPatient Provider Conflict9.2 Incidental FindingsMisattributed PaternityDiscovery of ConsanguinityIdentification of an Incidental Condition9.3 Privacy and ConfidentialityGenetics is a Family AffairSecret Information9.4 Working with couplesCouples in Conflict"It's not my body"9.5 Dealing with UncertaintyFetal Diagnosis and PrognosisFamily HistoryComplex ConditionsVariants of Uncertain Significance9.6 Fetal Sex DisclosurePatient's Desire to Know or NotTesting may Reveal Sex Chromosome Abnormalities (SCAs)Disorders Affecting a Specific SexTesting Only for SexFetal Sex may be "Difficult News"9.7 Patient Questions"What would you do?"When You Don't Know the Answer9.8 Testing a Fetus for Adult Onset Condition9.9 Barriers for ConsentPatient UnderstandingVoluntary Participation9.10 Rapidly Evolving TechnologiesAppendix AAppendix B Index