NT scan in between 11-14 weeks and an anomaly scan between 18-22 weeks gestation and a growth scan around 32-34 are basic scans needed for every woman.
If there is any abnormality noted in the growth scan, you will be asked for regular follow up. High risk women will be advised two levels of anomaly scan, one at 18 weeks and one at 22 weeks.
Ideally every woman needs to be screened for Down’s syndrome. Screening will be done based on first trimester NT scan and serum markers. Women who falls in high risk category will be advised for definitive testing with amniocentesis or Chorionic villus sampling (CVS)— Read more
Amniocentesis involves taking the amniotic fluid around the baby. The cells of baby are present in the amniotic fluid which are cultured and examined for any chromosomal abnormalities or single gene disorders
Who needs amniocentesis?
- Women who shows high risk for Down’s syndrome on screening.
- Previous baby affected with any chromosomal or other genetic abnormality.
- Any of the parent affected with an inherited condition which can be passed on to the baby (EX: Sickle cell anemia, Thalassemia).
When can the test be done?
Any time after 15 weeks. The amniotic membrane must be fused for the doctor to proceed with amniocentesis. So, in some women we might have to wait a little longer than 15 weeks
Is the test painful?
The pain during the test will be similar to the pain caused during blood test. A small needle will be passed through the mother s stomach and the fluid is withdrawn. In some women there might be some amount of discomfort for few hours after the procedure, which will subside after adequate rest
What are the instructions after the procedure?
After the procedure you will be advised to take rest for two days. Antibiotics will be prescribed for 3 days and Paracetamol tablet will be prescribed to be taken in case of any discomfort. No restrictions regarding food or drink before or after the procedure
How long does the procedure take?
The procedure takes 5-10 minutes. You will be advised to stay in the hospital for 2 hours for observation. If no complaints you can leave after 2 hours. No admission to the hospital s required.
Is there any risk with the procedure?
There is a risk of miscarriage rate- 1 in 1000 procedures (according to our centre statistics) Most commonly the miscarriage occurs in the first two weeks after the procedure.
When can we expect the results?
The results for the entire karyotype to come takes 3 weeks. There is an option of Fluorescent in situ hybridization (FISH) which gives the result for any sets of chromosomes out of the 23 sets in 4-5 days.
CVS is a procedure which involves taking some amount of placental tissue and culturing the cells to examine for chromosomal or genetic defects. It is done in between 11-14 weeks. The procedure involves a bigger needle. Hence local anaesthesia is given prior to the procedure. The procedure related miscarriage is 1 in 500 (statistics according to our centre). The results come in 4-5 days.
In multifetal pregnancies where there are more than two babies when the parents request one of the fetus will be reduced in order to prevent the complications associated with higher order births. It is usually done between 10- 14 weeks
Yes. Ultrasound is perfectly safe in pregnancy. It uses electricity to produce sound waves and thus produces an image. Unlike X rays and CT scan it does not involve any radiations. There is no harm to the fetus on getting frequent scans as well. However, we limit the use of doppler in the first trimester.
Double marker test is done in first trimester. It includes testing the level of
- Beta HCG
- PAPP A
Quadruple marker test is done in second trimester. It includes testing the level of
- Inhibin A
- Beta HCG
- Alfa fetoprotein
- Unconjugated Estradiol
They are used as screening tests for chromosomal anomalies (Trisomy 13, 18, 21)