Invasive Procedures

CVS is a test performed during pregnancy to check for all types of chromosomal abnormalities and prenatal diagnosis of certain genetic disorders in the baby.

1. When there is a ‘high risk’ for chromosomal disorders on first trimester screening
2. When there is an abnormality in the baby on the first trimester scan
3. To rule out genetic disorders like thalassemia, sickle cell disease, muscular dystrophy etc.
4. When you have a family history of a genetic disorder for which the genetic mutation is known with a diagnosis in the index child.

Local anaesthesia is given prior to the procedure. CVS is done by passing a needle through the mother’s abdomen under local anaesthesia to obtain a small amount of tissue from the placenta. The test is done under continuous ultrasound guidance so as to avoid the baby. There is small increased risk of miscarriage of around 1 in 100 for chorionic villus sampling. In about 1 in 100 patients, the culture may fail and the full karyotype may be unavailable. In some cases, the results may be inconclusive because of mosaicism.

The FISH report comes within 5 full working days; the karyotype report takes 3 weeks time. The timing of other results will depend on the test performed and usually varies between 7 to 10 working days.

Amniocentesis

Amniocentesis is a test performed during pregnancy to check for chromosomal disorders, certain genetic disorders and infections in the baby.

Indications include:

1. When there is a ‘high risk’ for chromosomal disorders on first trimester or second trimester screening (triple or quadruple marker)
2. When there is a high suspicion for Down syndrome on ultrasound in the second trimester
3. When there is a structural abnormality in the baby at the anomaly scan
4. When CVS could not be performed due to posterior placenta.
5. Uncommonly, amniocentesis may be done to confirm fetal infection when the mother is suspected to have certain infections, like rubella, CMV, toxoplasma, etc.

This test is usually done between 16 weeks of pregnancy; however it may be done anytime afterwards when indicated. Amniocentesis is done by passing a needle through the mother’s abdomen to obtain sufficient amniotic fluid .The test is done under continuous ultrasound guidance so as to avoid the baby and placenta.

There is small increased risk of miscarriage of around 1 in 200 with amniocentesis and 1 in 100 for chorionic villus sampling. Although all precautions are taken during the procedure to minimize infection, there remains a small risk of infection (1 in 1000).

Fetal blood sampling

A fetal blood sample may be taken to: diagnose genetic or chromo-some abnormalities check for and treat severe fetal anemia or other blood problems such as Rh disease check for fetal infection give certain medications to the fetus. There are several ways blood can be obtained from the fetus. After cleansing the mother’s abdomen with antiseptic, a long, thin needle is inserted into the mother’s uterus guided by ultrasound. Blood may be taken from the following sources: blood vessels of the umbilical cord (also called cordocentesis, or percutaneous umbilical blood sampling, or PUBS) a fetal blood vessel, usually in the liver or heart

Fetal blood transfusions are performed using a similar technique in cases of fetal anaemia (Rh isoimmunised pregnancies)

Multifetal Reductions

In case of higher order multiple pregnancy, it is advisable to reduce the number of fetuses to two in order to minimize risks of multiple pregnancy both to the mother as well to the fetuses. As the number of fetuses increases, the risks of preterm (early) delivery also increase: the average length of pregnancy for a singleton is 40 weeks whereas for twins it is 36 weeks. This reduces dramatically to 32 to 33 weeks for triplets and 28 to 29 weeks for quadruplets. The incidence of multiple pregnancy is increasing worldwide especially due to increase in the availability and uptake of artificial reproductive techniques. It may seem paradoxical in an In Vitro Fertilization (IVF) pregnancy that embryo reduction is advised after so much effort to get pregnant in the first place. However the aim of an IVF is not to just achieve a pregnancy but to give the mother a healthy baby at the end of pregnancy. This holds true for spontaneously conceived higher order multiple pregnancies as well. It is usually done between 11 to 13 weeks of pregnancy; at our centre we prefer to do it at around 12 weeks when we can do the first trimester screening and also rule out any structural abnormality in the babies. In addition, about 8 to 20% multiple pregnancies may reduce by themselves by the end of first trimester. The ‘vanishing’ twin does not have any adverse effect on the surviving fetus.

Genetic Counselling

Our fetal medicine Department faculty will discuss your history, and offer families with pregnancy complications the advanced fetal diagnostic and clinical resources.

We make sure you receive the best possible care.

Evaluation of your family history.

We will discuss the health of your pregnancy and make recommendations based on your family’s history.

Advice about non-invasive and minimally invasive tests.

When you need help understanding the purpose, risks, benefits and limits of diagnostic procedures, we will talk with you about what to expect.

Compassionate family counseling.

It can be difficult to navigate the emotional challenges that surround the diagnosis of a fetal condition. We are here to provide you with support when you need it.

Compassionate family counseling.

When a fetal treatment is a possibility, we can act as your advocate to help you understand the situation and to make sure you and your unborn baby receive the best possible care.

High Risk pregnancies

The following high risk pregnancy conditions are evaluated and monitored at our centre:

1. Pre-pregnancy counselling
1. Recurrent pregnancy loss
2. Previous unexplained intrauterine fetal demise (IUFD) or stillbirth
3. Known genetic disorder in family
2. Pregnancy with previous child affected by thalassemia
3. Pregnancy with suspected fetal infection (TORCH, chickenpox)
4. Pregnancy with Diabetes
5. Pregnancy with chronic hypertension
6. Pregnancy with autoimmune and connective tissue disorders
1. Pregnancy with thrombophilias
2. Systemic Lupus Erythematosus (SLE)
3. Sjogren’s syndrome
4. Rheumatoid arthritis
7. Pregnancy with suspected morbidly adherent placenta (MAP)
8. Management of fetal growth restricted babies (FGR)
1. Dopplers
2. Non stress test (CTG)