Fetal Diagnosis & Counseling of Pregnancy Options.

Presentation on theme: "Fetal Diagnosis & Counseling of Pregnancy Options."— Presentation transcript:

1 Fetal Diagnosis & Counseling of Pregnancy Options

2 Overview What is prenatal (fetal) diagnosis? Options Available for Fetal Diagnosis –Screening –Diagnostic –Pictures, Examples Options for Pregnancy Management –Termination –Continuation –Hospice –Adoption

3 What 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 serious Serious abnormalities lead to mental or physical disabilities or even death Birth defects are the leading cause of infant mortality & significant cause of premature death, chronic illness and long-term disability

4 What is the Risk of Having a Fetus with an Abnormality? Overall risk – ~ 4% Worldwide - 6 million affected babies born/year U.S. - 150,000 affected babies born/year Most common abnormalities –Congenital Heart Disease -- 8/1000 –Trisomy 21 – 1/700 –Neural Tube Defect -- 1/1000 –Cystic fibrosis – 1/3000

5 History of prenatal diagnosis Ultrasound (US) –Introduced in the 1950s Amniocentesis –First done in 1877 –First done for chromosomal studies in 1966 –Common since the 1970s Chorionic villus sampling (CVS) –First done in 1968 –Greater acceptance in 1980s-90s Rapid expansion of serum & US screening options, wide-spread use – 1990s to present

6 What Can Be Done Prior to Conception? Identify women/couples at risk –Family history: birth defects or genetic dz –Medications: Coumadin, Accutane –Exposures: smoking, EtOH, drugs Refer to genetic counselor Consider carrier testing –Cystic Fibrosis, Sickle Cell, Tay-Sachs Folate -  risk of NTD

7 What Options During pregnancy? Screening vs. diagnostic testing Provide information early Factors that may be considered –Desire to terminate if an abnormality is found –Desire to have as much information for preparation –Delivery planning

8 What is a Screening Test? A test done to identify a disease or defect by the application of tests, examinations or other procedures Provides individual RISK ASSESSMENT Pro:  number of procedures done for diagnosis & therefore,  procedure-related complications Con: not diagnostic, may miss target

9 What is a Diagnostic Test? A test that will definitively identify a disease or defect Prenatal diagnostic test –Chromosomal abnormality (aneuploidy), gene change (Sickle cell) PRO: DEFINITIVE ANSWER CON: Risks associated with the diagnostic procedure

10 What Screening Tests Are Available? Ultrasound at any time 1 st trimester – 10-14 weeks –Serum analytes: PAPP-A, free ß-hCG –Ultrasound evaluation of nuchal translucency 2 nd trimester – 15-21 weeks –Serum analytes: AFP, uE3, hCG, inhibin A “Non invasive” prenatal diagnosis –Maternal Serum – cell free DNA

11 Screening Options TestWhen DoneDetection Rates 1st trimester (NT + 2 serum) 10-14 weeksT21 -- 83% T18 – 80% Ultrasound18-20 weeksT21 -- 60%; T18 -- 85% NTD -- 70-98% Quadruple screen (4 serum analytes) 15-21 weeksT21 -- 75-80%; T18 -- 60% NTD -- 80-90% *Integrated screen (1st trimester screen + quadruple screen) 10-14 weeks 15-21 weeks T21 -- 92% T18 -- 90% NTD -- 80% Maternal serum>7 weeksT21 - >99% Other aneuploidy?

12 What if the Screen is Abnormal? Discussion with patient and her family Discussion with primary provider Referral to genetic counselor Detailed anatomical US –50% of T21 fetuses have a normal US! Offer diagnostic testing

13 What Diagnostic Tests Are Available? Chorionic villus sampling – 10-13 weeks Amniocentesis – > 15 weeks Fetal Blood Sampling – rarely done Ultrasound

14 Chorionic Villus Sampling 10-13 weeks Trophoblasts cultured Advantages –Early diagnosis Disadvantages –Loss rate 0.5-1% –1% risk of confined placental mosaicism http://www.pennhealth.com/health_info/pregnancy/000242.htm

15 Amniocentesis > 15 weeks Remove 15-20 ml of amniotic fluid Amniocytes cultured Advantages –Can test AFP levels. Disadvantages –Loss rate 0.1-0.5% –Later diagnosis

16 ACOG’s Stance on Prenatal Screening & Diagnosis All women should be offered aneuploidy screening before 20 weeks, regardless of maternal age All women should have the option of invasive testing regardless of age Primary provider should be able to discuss the detection rates, false positive rates, disadvantages & limitations ACOG Practice Bulletin #77: Screening for Fetal Chromosomal Abnormalities

17 Fetal Blood Sampling (Cordocentesis) Removal of blood from umbilical cord Rarely done Done when diagnostic information can not be obtained through amniocentesis, CVS, US or the results of these tests were inconclusive Performed after 17 weeks Potential indications: suspected fetal infection, anemia, thrombocytopenia Loss rate - 2%

18 How is Ultrasound Used for Screening & Diagnosis?

19 1st Trimester US What Can We See? Markers of Aneuploidy & Congenital Heart Disease –  Nuchal translucency –Absent nasal bone –Tricuspid regurgitation

20 1st Trimester US What Can We See? AnencephalyNormal Fetus

21 1st Trimester US What Can We See? Multiple Gestation

22 2nd Trimester Ultrasound What Can We See? Lethal anomalies –Anencephaly –Skeletal dysplasias –Renal agenesis Moderate to severe anomalies –Congenital diaphragmatic hernia –Heart defects –Neural tube defects –Gastroschisis, Omphalocele

23 2nd Trimester Ultrasound What Can We See? Relatively minor abnormalities –Cleft lip/palate –Club foot –Polydactyly

24 http://i.b5z.net/i/u/909479/i/med_sketch500.gif http://www.obgyn.net/us/cotm/0006/Anencephaly%205.jpg Anencephaly

25 Neural Tube Defects

26 Gastrochisis

27 Bilateral Cleft Lip & Palate

28 Club Foot & Polydactyly

29 What Happens Once a Diagnosis is Made? Breaking the bad news….. Difficult US technologists often the 1st to recognize - awkward for them & patient Acknowledge concern “Ruined the pregnancy for me”

30 What Are The Options for Management? Termination by D&C or D&E Termination by induction of labor –Can be done anytime after 15 weeks –Always done after 24 weeks –Allows parents to spend time with fetus –Allows complete autopsy Continuation of the pregnancy –Preparation, adoption, delivery planning

31 Do Fetuses Feel Pain? Hotly debated Neuroanatomical system complete by 26 weeks A developed neuroanatomical system is necessary but not sufficient for pain experience Pain experience also requires development of the mind to accommodate the subjectivity of pain Unclear May consider cord/intracardiac injection of KCl prior to termination or induction Derbyshire SWG BMJ 2006;332:909-912

32 http://video.on.nytimes.com/index.jsp?auto_band=x&rf=sv& fr_story=79cf26acead199fa0a000074e41deda20072c923

33 Thank You!

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35 Preimplantation Genetic Diagnosis Alternative to conventional prenatal diagnosis Diagnose cytogenetic or single gene disorders prior to embryo implantation Biopsy of 1-2 cells from an in vitro embryo Allows couples to avoid intrauterine transfer of affected embryos

36 Preimplantation Genetic Diagnosis Advantages –Avoid pregnancy termination –Avoid procedure related pregnancy loss –Improve ongoing pregnancy rates Disadvantages –Must undergo IVF –Expensive –Can only be done for anomalies associated with cytogenetic or single gene disorders

37 ACOG’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."

38 Multifetal 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 gestation Goal of ST is to prevent the survival of a severely impaired fetus of a multiple pregnancy in which the fetuses are discordant for anomalies

39 How Can Prenatal Diagnosis Be Useful? Managing the remaining weeks of the pregnancy Determining the outcome of the pregnancy Planning for possible complications with the birth process Planning for problems that may occur in the newborn infant Deciding whether to continue the pregnancy Finding conditions that may affect future pregnancies