Second Trimester Screening

Second Trimester Screening (STS) is performed between 15th and 20th week (16th to 18th is recommended). Ideally, STS is performed in conjunction with the First Trimester Screening (FTS), but if the woman missed her FTS, Second Trimester Screening is recommended to diagnose any abnormalities.

Second Trimester Screening

Second trimester screening tests include:

Triple Screen measures three substances in blood:

AFP, uE3(estriol) and hCG.

It leads to the detection of:

  • 0% to 70% of Down syndrome cases
  • 60% of trisomy 18 cases
  • 80% of open neural tube defects

Abnormal levels of these substances may indicate:

  • neural tube defects such as spina bifida and anencephaly
  • multiple birthtwins or triplets.
  • Down syndrome or Edwards syndrome.

Triple marker screen tests help prospective parents prepare and assess options. It further allows doctors to examine a fetus more closely for other signs of complications.

The test is often recommended for women who:

  • are 35 years old or older
  • have a history of birth defects in the family
  • have diabetes and use insulin
  • had a viral infection during pregnancy


Diagnostic tests provide in depth analysis of the chromosomes. They are more invasive than screening tests and detect minute abnormalities which otherwise go undetected. Screening tests simply outline the risks whereas diagnostic tests provide definitive analysis on the possibility of the risk.

LifeCell recommends the following diagnostic tests:

The human body contains genetic information that is bundled into packages called chromosomes. Any change in the genetic combinations, like addition or deletion within chromosomes or of the chromosomes, can cause medical conditions like birth defects, developmental delays, autism and other health issues.

Chromosomal Microarray uses advanced technology to provide detailed genetic testing by detecting both large and small chromosomal change. Through a combination of Copy Number Probes( known as Gains) and SNP probes, CMA is able to detect smaller changes in chromosomes that normally go undetected in a routine genetic analysis.

CMA in Prenatal Settings:

In a prenatal setting, the CMA is used to predict the fetal outcome. CMA offers added advantage over traditional Karyotyping by detecting submicroscopic deletions and duplications that are not detected by smaller resolutions.

CMA is used prenatal diagnosis:

  • If maternal blood tests during pregnancy were abnormal, indicating an increased chance of a medical anomaly or birth defect.
  • If an anomaly was detected on ultrasound.
  • If the mother already has a child with birth defects such as chromosomal changes.
  • In case of Recurrent Pregnancy Loss.
  • In case of advanced maternal age.


CytoScan HD

Cytoscan 750K

Cytoscan Optima

Where to be Used?

High Resolution analysis of CNVs constitutional  post natal samples

Analysis of gains and loss for constitutional post natal samples

Detection of gross aneuploidies at low cost and low resolution

Probe Details

High Density coverage with > 2.6 million probes

CNV Probes = 550,000

SNP Probes = 200,000

Total Probes = 750,000

CNV Probes = 18,018

SNP Probes = 148,450

Total Probes = 315,000

Sample Types

Blood, Buccal Swabs, Saliva, fresh & frozen tissues, uncultured or cultured cells, CVS , Amniocentesis,POC, etc.

Blood, Buccal Swabs, Saliva, fresh & frozen tissues, uncultured or cultured cells, CVS , Amniocentesis,POC, etc.

Blood, Buccal Swabs, Saliva, fresh & frozen tissues, uncultured or cultured cells, CVS , Amniocentesis,POC, etc.

Analytical Claims

Gains  < 10-25 Kb

Losses < 10-25 kb

AOH> 1mb

Mocaissim > ~ 15%

Gains  200-400 kb

Losses  200-400 kb

AOH> 5 mb

Mocaissim > ~ 15-20%

Gains  2 mb

Losses  1 mb

AOH> ~5 mb

Mocaissim > ~ 20%

396 genes at 25m/100kb

For pricing & other information