Fetal & Genetic Screening - Know More About It!

Prenatal Diagnosis is the diagnosis of the fetus or unborn baby. By prenatal diagnosis, doctors examine the developing baby. There are two main methods for prenatal diagnosis, Chorionic Villus Sampling (CVS), and Amniocentesis. However, the prenatal diagnosis consists of several tests which help doctors to find out the genetic disorder of the fetus.

According to many studies, some parents are at higher risk of having a baby with a genetic problem or disorder. Due to this reason, it is advisable to diagnose a baby before birth so that parents can be aware of the problem and manage it efficiently. These diagnostic tests will help parents to take better decisions for the health of their baby.

Prenatal diagnosis is also necessary as there are problems which can be treated before the birth of the baby.  However, other problems need immediate attention after the delivery.

Benefits of Prenatal Diagnosis -

Prenatal Diagnosis is beneficial for:

• Managing the duration of the pregnancy

• Preparing for possible difficulties during pregnancy or with the birth process

• Determining the consequence of the difficult pregnancy

• Planning for diseases/problems/disorders that may occur in the infant

• Detecting conditions that may influence future pregnancies

• Determining whether to continue the pregnancy

Test for Prenatal Diagnosis -

• Amniocentesis

• Chorionic villus sampling

• Ultrasonography

• Maternal serum beta-HCG

• Fetal blood cells in maternal blood

• Pregnancy-associated plasma protein A

• Maternal serum unconjugated estriol

• Inhibin A

• Maternal serum alpha-fetoprotein

What is Amniocentesis? 

Amniocentesis is an invasive method and usually performed during 14 and 20 weeks of the pregnancy. In this procedure, a needle is inserted into the amniotic cavity of the uterus through the lower abdomen. Before performing Amniocentesis, an ultrasound is done to determine the gestational age, see if there is sufficient amniotic fluid present, and check the location of the placenta and fetus. With the help of injection, doctors withdraw a small amount of amniotic fluid and send it in the laboratory to test:

• Infection

• Genetic abnormalities

• Signs for lung development

Chorionic Villus Sampling (CVS) -

Chorionic Villus Sampling or CVS is one of the methods in the Prenatal diagnosis process in which a catheter is inserted into the uterus through the vagina and cervix. It is done to withdraw the placental chorionic villi cells. After that, the cells examined and analyzed by different techniques. CVS usually performed during the 9.5 to 12.5 weeks of pregnancy. Generally, the cells withdraw in CVS is for chromosome analysis to find out the karyotype of the fetus.

Techniques Used for Pathologic Examination

These are some of the techniques used in the pathology to determine the problems and issues of the fetus:

• Gross Examination

• Microscopic Examination

• Radiography

• Microbiologic Culture

• Karyotyping

• Fluorescence in Situ Hybridization (FISH)

• DNA Probes

• Flow Cytometry

• Biochemical Analysis

• Electron Microscopy (EM)

Take Away -

Prenatal diagnosis is very important as it gives an idea about the pregnancy complications and future complication that a child may suffer. This also helps in curing and treating the problems during fetal development.