Presentation on theme: "Fetal Diagnosis & Counseling of Pregnancy Options"— Presentation transcript:
1Fetal Diagnosis & Counseling of Pregnancy Options Brian L Shaffer, MD
2Overview What is prenatal (fetal) diagnosis? Options Available for Fetal DiagnosisScreeningDiagnosticPictures, ExamplesOptions for Pregnancy ManagementTerminationContinuationHospiceAdoptionThe primary objectives of this hour are to talk about what options are currently available for fetal diagnosis – including screening methods & diagnostic techniques, highlighting the differences between the two – and giving some examples – and ending with a discussion about how we go about counseling patients & families regarding the options for pregnancy management – including termination or continuation of pregnancy.At the very end, I’d like to show a brief (6 minute) video-clip highlighting the experiences of two couples who have chosen continuation of affected pregnancies.This talk is intended to be relatively informal, so please feel free to ask questions or make additional comments at any time.
3What is a Birth Defect? “Congenital anomaly” Any abnormality of structure and/or function present at birth> 4,000 different known birth defects ranging from minor to seriousMinor may be cosmetic onlySerious abnormalities lead to mental or physical disabilities or even deathBirth defects are the leading cause of infant mortality & significant cause of premature death, chronic illness and long-term disability
4What is the Risk of Having a Fetus with an Abnormality? Overall risk – ~ 4%Worldwide - 6 million affected babies born/yearU.S ,000 affected babies born/yearMost common abnormalitiesCongenital Heart Disease -- 8/1000Trisomy 21 – 1/700Neural Tube Defect -- 1/1000Cystic fibrosis – 1/3000So, what is the risk of having a fetus with an abnormality?The overall risk is 2 to 4 %Which means that worldwide – approximately 6 million affected babies are born each yearAnd in the US – approximately 150,000 affected babies are born each yearThe most common abnormalities include congenital heart defects, Trisomy 21, and neural tube defects in that order
5History of prenatal diagnosis Family historyUltrasound (US)Introduced in the 1950sAmniocentesisFirst done in 1877 (for polyhydramnios)First done for chromosomal studies in 1966Common since the 1970sChorionic villus sampling (CVS)First done in 1968Greater acceptance in 1980s-90sRapid expansion of serum & US screening options, wide-spread use – 1990s to presentJust to provide some perspective on the field of fetal screening and diagnosis…..It really is a reasonably new field.The use of ultrasound for fetal diagnosis was just introduced in the 1950s…. And while the first amniocentesis was performed in the late 1800s, the first time that it was used to do a karyotype on a fetus was in just 40 years ago.Chorionic villus sampling was introduced shortly after amnio It wasn’t really until the 1950s that US and amniocentesis began to be
6What Can Be Done Prior to Conception? Identify women/couples at riskFamily history: birth defects or genetic dzMedications: Coumadin, AccutaneExposures: smoking, EtOH, drugsRefer to genetic counselorConsider carrier testingCystic Fibrosis, Sickle Cell, Tay-SachsFolate - risk of NTDSo, how do we go about assessing one’s risk of having a baby with an abnormality, or making a diagnosis of a fetal abnormality?Ideally, we talk to women & couples prior to pregnancy. Preconceptionally, it’s nice if we can identify those at greatest risk
7What Options During pregnancy? Screening vs. diagnostic testingProvide information earlyPersonal decisionFactors that may be consideredDesire to terminate if an abnormality is foundDesire to have as much information for preparationDelivery planning
8Goal of Prenatal Screening & Diagnosis To provide a safe & efficacious means of identifying affected pregnancies for those women or couples who wish to exercise reproductive choice or to plan for the care of an affected child
9What is a Screening Test? A test done to identify a disease or defect by the application of tests, examinations or other proceduresProvides individual RISK ASSESSMENTAds: number of procedures done for diagnosis & therefore, procedure-related complicationsDisads: not diagnostic, may miss target
10What is a Diagnostic Test? A test that will definitively identify a disease or defectPrenatal diagnostic testChromosomal abnormality (aneuploidy), gene change (Sickle cell)Ads: DEFINITIVE ANSWERDisads: Risks associated with the diagnostic procedure
12Screening Options Test When Done Detection Rates 1st trimester (NT + 2 serum)10-14 weeksT %T18 – 80%Ultrasound18-20 weeksT %; T %NTD %Quadruple screen(4 serum analytes)15-21 weeksT %; T %NTD %*Integrated screen(1st trimester screen + quadruple screen)T %T %NTD -- 80%Maternal serum>7 weeksT21 - >99%Other aneuploidy?
13What if the Screen is Abnormal? Discussion with patient and her familyDiscussion with primary providerReferral to genetic counselorDetailed anatomical US50% of T21 fetuses have a normal US!Offer diagnostic testing
16Amniocentesis > 15 weeks Remove 15-20 ml of amniotic fluid Amniocytes culturedAdvantagesCan test AFP levels.DisadvantagesLoss rate %Later diagnosis
17ACOG’s Stance on Prenatal Screening & Diagnosis All women should be offered aneuploidy screening before 20 weeks, regardless of maternal ageAll women should have the option of invasive testing regardless of agePrimary provider should be able to discuss the detection rates, false positive rates, disadvantages & limitationsACOG Practice Bulletin #77: Screening for Fetal Chromosomal Abnormalities
18Fetal Blood Sampling (Cordocentesis) Removal of blood from umbilical cordRarely doneDone when diagnostic information can not be obtained through amniocentesis, CVS, US or the results of these tests were inconclusivePerformed after 17 weeksPotential indications: suspected fetal infection, anemia, thrombocytopeniaLoss rate - 2%
19How is Ultrasound Used for Screening & Diagnosis?
201st Trimester US What Can We See? Markers of Aneuploidy & Congenital Heart Disease Nuchal translucencyAbsent nasal boneTricuspid regurgitation
211st Trimester US What Can We See? Normal FetusAnencephaly
221st Trimester US What Can We See? Multiple Gestation
232nd Trimester Ultrasound What Can We See? Lethal anomaliesAnencephalySkeletal dysplasiasRenal agenesisModerate to severe anomaliesCongenital diaphragmatic herniaHeart defectsNeural tube defectsGastroschisis, Omphalocele
242nd Trimester Ultrasound What Can We See? Relatively minor abnormalitiesCleft lip/palateClub footPolydactyly
30What Happens Once a Diagnosis is Made? Breaking the bad news…..DifficultUS technologists often the 1st to recognize - awkward for them & patientAcknowledge concern“Ruined the pregnancy for me”As prenatal testing becomes increasingly sophisticated and routine, more parents are learning devastating news before their babies are born. In many ways, the ability to diagnose a fatal condition has raced ahead of the ability to care for these families and their babies.
31Breaking the Bad News …. Present all of the facts Survival, morbidity, quality of lifeShow empathy & compassion at all timesAllow the couple time to process the informationProvide them with additional resourcesGenetic counselorSocial workLiterature, websites (http://www.birthdefects.org/)Multidisciplinary clinics : Pediatric surgeons, Cardiologists, NeonatologistsDelivery planning
32Breaking the Bad News…..Do not let them leave your office without having all of their immediate questions answered & addressedEncourage them to bring additional support people as neededOffer to meet with them again at anytime
33What Are The Options for Management? Termination by D&C or D&ETermination by induction of laborCan be done anytime after 15 weeksAlways done after 24 weeksAllows parents to spend time with fetusAllows complete autopsyContinuation of the pregnancyPreparation, adoption, delivery planning
34Nondirective counseling I cannot overemphasize the importance of this concept
35Do Fetuses Feel Pain? Hotly debated Neuroanatomical system complete by 26 weeksA developed neuroanatomical system is necessary but not sufficient for pain experiencePain experience also requires development of the mind to accommodate the subjectivity of painUnclearMay consider cord/intracardiac injection of KCl prior to termination or inductionImportant neurobiological developments occur at 7, 18, and 26 weeks gestation and are the proposed periods for when a fetus can feel pain. The subjective experience of pain cannot be inferred from anatomical developments because these developments do not account for subjectivity and the conscious contents of pain.Derbyshire SWG BMJ 2006;332:
36When A Family Decides to Continue the Pregnancy Offer support without judgmentContinued, regular prenatal careSocial workLocal & online support groupsPerinatal hospice organizationsEncourage them to make plans for deliveryBirth plan, support peopleSurgical intervention for fetal distressEncourage them to make plans for after deliveryNeonatal resuscitation or interventions?Neonatologist20-40% of famillies opt to carry the pregnancy to term40 perinatal hospice programs have been started in the US in the last decadeOften associated with hospitals, hospice nurses, social workers - birthing classes, guidance on how to tell other children in the family that the new baby will not be growing up with themIf the newborn lives beyond a few days, the hospice staff teaches the family how to take care of the baby at homeHelps to give families control over an event that could otherwise cruch them. Goal is to help ease the isolation many families face in dealing with profound griefNeed to make decisions regarding intervention intrapartum, intervention post-delivery, ie intubation, feeding tubes, IV fluids, and surgery
40Preimplantation Genetic Diagnosis Alternative to conventional prenatal diagnosisDiagnose cytogenetic or single gene disorders prior to embryo implantationBiopsy of 1-2 cells from an in vitro embryoAllows couples to avoid intrauterine transfer of affected embryosFor PGD, the early embryo is examined after IVF for inherited diseases or to determine the sex of the embryo for sex-related genetic disorders. The process starts with a basic IVF. When the embryo is at the 6- to 8-cell stage, 1-2 cells (blastomeres) are removed and sent to the genetic laboratory for diagnosis using either polymerase chain reaction (PCR) or fluorescence in situ hybridization (FISH) techniques, depending on which disease is being sought. The unaffected embryos are then transferred into the mother's uterus.In certain situations in which the genetic problem is only with the female, a polar body can be removed from the eggs and tested before fertilization.
41Preimplantation Genetic Diagnosis AdvantagesAvoid pregnancy terminationAvoid procedure related pregnancy lossImprove ongoing pregnancy ratesDisadvantagesMust undergo IVFExpensiveCan only be done for anomalies associated with cytogenetic or single gene disorders
42ACOG’s Opinion"All women, regardless of age, should have the option of invasive testing. A woman's decision to have an amniocentesis or CVS is based on many factors, including the risk that the fetus will have a chromosomal abnormality, the risk of pregnancy loss from an invasive procedure, and the consequences of having an affected child if diagnostic testing is not done. Studies that have evaluated women's preferences have shown that women weight these potential outcomes differently. The decision to offer invasive testing should take into account this preference sand should not be solely age based. The differences between screening and diagnostic testing should be discussed with all women. Thus, maternal age of 35 years alone should no longer be used as a cutoff to determine who is offered screening versus who is offered invasive testing."
43Multifetal Pregnancy Reduction & Selective Termination Goal of MPR is to reduce the risk of complications associated with higher order pregnancies by decreasing the number of fetuses in the gestationGoal of ST is to prevent the survival of a severely impaired fetus of a multiple pregnancy in which the fetuses are discordant for anomaliesPrenatal diagnosis employs a variety of techniques to determine the health and condition of an unborn fetus. Without knowledge gained by prenatal diagnosis, there could be an untoward outcome for the fetus or the mother or both. Congenital anomalies account for 20 to 25% of perinatal deaths. Specifically, prenatal diagnosis is helpful for:Managing the remaining weeks of the pregnancyDetermining the outcome of the pregnancyPlanning for possible complications with the birth processPlanning for problems that may occur in the newborn infantDeciding whether to continue the pregnancyFinding conditions that may affect future pregnanciesThere are a variety of non-invasive and invasive techniques available for prenatal diagnosis. Each of them can be applied only during specific time periods during the pregnancy for greatest utility. The techniques employed for prenatal diagnosis include:UltrasonographyAmniocentesisChorionic villus samplingFetal blood cells in maternal bloodMaternal serum alpha-fetoproteinMaternal serum beta-HCGMaternal serum estriol
44How Can Prenatal Diagnosis Be Useful? Managing the remaining weeks of the pregnancyDetermining the outcome of the pregnancyPlanning for possible complications with the birth processPlanning for problems that may occur in the newborn infantDeciding whether to continue the pregnancyFinding conditions that may affect future pregnancies