Amniocentesis can help check if a baby has caught certain infections in the womb, especially cytomegalovirus (CMV) and toxoplasmosis, which can sometimes affect the baby’s brain, eyes, hearing, or overall development.​ How common? CMV is one of the most common infections in pregnancy; about 1% of pregnant women experience a first-time CMV infection, and a proportion of these infections are passed to the baby.​ Toxoplasmosis in pregnancy is less common, with new infection in a

What Is Toxoplasmosis? Toxoplasmosis is an infection caused by a parasite called Toxoplasma gondii. While it often causes no symptoms or...

If a woman is infected with cytomegalovirus (CMV) for the first time from about two months before pregnancy up to the first three months...

The FTS must be performed between 11+ weeks to 13 weeks 6 days gestation, best around 12 weeks. This is performed via: 1. History 2....

One needs to understand the different types of chromosomal abnormalities to decide which tests to do. 1. Large chromosomal abnormalities...

The majority of fetuses with increased nuchal translucency (NT) detected at the routine first trimester scan at 11-13 weeks gestation are...

Second Trimester Screening Scan or Fetal Anomaly Scan at 18-22 weeks This scan typically takes 30 minutes but may take longer if the baby...

This is usually done at 30 to 37 weeks. The following details are assessed at this scan: a) Measurements of head circumference,...

Invasive diagnostic procedures like amniocentesis and chorionic villus sampling (CVS) are performed under ultrasound guidance to obtain amniotic fluid and chorionic villi (or placental tissue) respectively to check for certain conditions during the pregnancy. These procedures are safe when performed by experienced operators though they are associated with procedure-related risks of miscarriage ranging from 0.1-0.3%. Antibiotics used during the procedure have not been shown t

QF-PCR is a common test used in many laboratories for the quick identification of the common chromosomal aneuploidies like Trisomies 21/18/13 and sex chromosomal aneuploidies such as 45XO, 47 XXX, 47XXY and 47XYY. It checks on the number of specific chromosomes like 21, 18, 13, X and Y. QF-PCR technique allows the results to be released within 2-3 working days. It is a test performed on amniotic fluid and chorionic villi obtained via amniocentesis and chorionic villus samp

Conventional karyotype is a genetic test that examines the size, shape and number of chromosomes in a sample of cells. The turn around time for this test is about 2 weeks, and may take longer if the cell culture is slow. Common chromosomal disorders such as Down syndrome (Trisomy 21), Edward syndrome (Trisomy 18), Patau syndrome (Trisomy 13), Turner syndrome (45XO) and other sex chromosomal abnormalities (e.g. 47XXX, 47XXY, 47XYY) can be diagnosed by a conventional karyotyp

Chromosomal microarray (CMA) test allows the detection of clinically significant microdeletions or microduplications that are bigger than 50,000 to 100,000 DNA bases, a resolution that is 50-100 x higher than that of conventional karyotype. It detects most gross chromosomal abnormalities detected by standard karyotype. Since 2010, the American College of Medical Genetics has recommended CMA test (instead of karyotype) as the first tier testing in individuals with with develo

Introduction DNA sequencing is the process of finding the order of the building blocks (i.e. nucleotides) of the genetic code of an individual. Whole exome sequencing (WES) is a widely used next-generation sequencing (NGS) method that involves sequencing the protein-coding regions (exome) of the genome. The human exome represents 1-2% of the genome, and mutations within the exome are known to cause about 85% of the diseases caused by genes. Therefore WES is thought to be a

Introduction DNA sequencing is the process of finding the order of the building blocks (i.e. nucleotides) of the genetic code of an individual. Whole genome sequencing (WGS) is a next-generation sequencing (NGS) method that is increasingly being used, and it involves sequencing both the non-protein coding (introns) and protein coding (exon) regions in an individual. It is currently the most comprehensive genetic test available and would obviate the need to do WES and CMA.

Single gene testing may be performed on amniocentesis or CVS sample if a specific gene abnormality is suspected because of: 1. very unique features on ultrasound scan 2. previous history of such a specific gene abnormality in a previous baby where parents were found not to have carry similar genes (usually such cases are counselled that there is a 1-2% risk of recurrence) 3. family history of a genetic disease where: a) both parents are known to be carriers of a known autoso

Targeted gene panels may be performed on amniocentesis or CVS sample if a specific abnormalities are suspected because of specific fetal abnormalities detected on ultrasound scan (e.g. increased nuchal translucency, heart abnormalities, brain abnormalities). The main advantages of doing targeted gene panels are that: 1. only specific genes in the panel are tested for, and hence avoids the difficulty sometimes of interpreting variants of unknown significance when using more e