This document discusses prenatal diagnosis, which involves procedures to diagnose genetic abnormalities or structural issues in an embryo or fetus. Prenatal diagnosis allows for timely medical care or decisions about continuing the pregnancy. It outlines common indications for prenatal diagnosis like advanced maternal age or family history of issues. Methods described include invasive tests like amniocentesis and chorionic villus sampling, and non-invasive options like ultrasounds and blood tests. The purposes and uses of prenatal diagnosis are to provide counseling, treatment options, and prepare parents for any health problems identified before or after birth.

1. PRENATAL DIAGNOSIS
Usha Rani S.
DASMAHE
Nandhini
Madhuri
M.Sc.

2. Outline
• Introduction
• What is prenatal diagnosis
• Purpose of prenatal diagnosis
• Indication
• Methods
• Uses
• Summary

3. • The Pre-natal Diagnostic Technique
(Regulation and Prevention of Misuse).
Act 1994
• Revised in April 2003
• The Pre-conception and Pre-natal
Diagnostic Technique(prohibition of
sex selection)
Introduction

4. Prenatal diagnosis
• Procedures undertaken to diagnose genetic
abnormalities and structural anomalies often early
embryo and fetus in order to undertake timely
prenatal counseling and appropriate interventions.
• It allows timely termination of pregnancy thereby
preventing wastage and perinatal mortality.

6. Prenatal diagnosis
Allows :
• timely medical treatment of a condition before or
after birth
• parents to make decisions regarding whether to
abort a fetus with a diagnosed condition
• parents to prepare psychologically, socially,
financially, and medically for a baby with a health
problem or disability.
• determine the outcome of pregnancy.

7. Indications for prenatal diagnosis
•Advanced maternal age
•Previous child with a chromosome abnormality
•Women who are pregnant with multiples (twins or more)
•Family history of single gene disorder
•Family history of a neural tube defect
•Family history of other congenital structural abnormalities
•Abnormalities identified in pregnancy
• Women who have previously had miscarriages
•Other high risk factors(consanguinity, poor obst., Maternal
illnesses)

8. Methods of prenatal diagnosis
Invasive Non-invasive
Amniocentesis. Ultrasonography
Cordocentesis. MRI
CVS Cell-free fetal DNA
Biopsy from fetal tissue. Triple test
Coelocentesis

9. Amniocentesis
• -Performed in II
trimester. trimesterZ
-Widely available.
• -1 in 300-500 women
will
• misc will m miscarry
•

10. Chorionic Villus Sampling
• Performed in 2nd trimester
• Specialized technique
• Risk same as amniocentesis

11. Cordocentesis
• Also called as PUBS
• Done after 18 weeks of
pregnancy
• 2 in 100 women will
miscarry

12. Fetal tissue biopsy
• Performed between 17-20
weeks gestation
• <1 in 1000 women shows
infection

13. Coelocentesis
• Performed before 10 weeks of pregnancy
• Coelomic space between amniotic membrane and
uterine cavity
• Fetal loss=0 or <that of amniocentesis

14. Ultrasonography
• Medical imaging technique that uses high frequency
sound waves.
• It frequency range of 1-12 megahertz
• Developing embryo can be visualized at about 6
weeks of gestation

15. Magnetic Resonance Imaging
• MRI is combined with ultrasound usually at or
after 18 weeks of gestation
• MRI is a risk-free method

16. Cell-free fetal DNA
• cffDNA is fetal DNA circulating freely in maternal
blood stream
• It is sampled by venipuncture on the mother
• cffDNA can first be observed as early as 7 weeks
gestation, and the amount of cffDNA increases as the
pregnancy progresses

17. Triple test
• Also called as double test or quadruple test
• Triple test measure:
-alpha-fetoprotein(AFP)
-human chorionic gonadotropin(HCG)
-unconjugated estriol(UE3)

18. Triple test screens for following fetal disorders

19. Applications of prenatal diagnosis
Maternal serum screening:-• Fetoprotein, estriol and HCG estimation
Ultrasonography:-•Structural abnormalities
Amniocentesis:- • Fetoprotein and acetylcholinesterase
• Chromosomal analysis
• Biochemical analysis
Chorionic villus sampling:- • DNA analysis
• Chromosomal analysis
• Biochemical analysis
Fetal blood sampling:- • Chromosomal analysis
• DNA analysis

20. Summary
•The commonest indication of prenatal diagnosis is advanced
maternal age, family history of chromosome, single gene or
structural abnormality and pregnancies with multiples
•The significance of most prenatal diagnostic findings is clear.
•It can be carried out by non-invasive procedures(MS-AFP for
NTD, triple test for Down‘s sy., and US for structural
abnormalities)
•Invasive procedures as amniocentesis or CVS is usually requires
for diagnosis of chromosome and single gene disorders
•Invasive procedures convey small risk for miscarriage(0.5-1%
for amniocentesis,2-3% for CVS)

21. THANK
YOU