Definition

Karyotyping of fetal umbilical cord blood obtained by cordocentesis is considered the gold standard for rapid fetal chromosome analysis in the second and third trimester. Its indications include a positive NIPT result, structural ultrasound anomalies and confirmation after amniocentesis.

Method

Cell culture

Accepted sample types

Cord blood (heparinized)

Inheritance

Reflects the fetally derived chromosome structure (mostly de novo numerical/structural abnormalities); postnatal cord blood sampling is aimed at evaluating congenital anomalies.

Related Tests

Inheritance Patterns

Describes how a genetic condition is passed on within a family. There are five main patterns

Go to term →

Carrier (Heterozygous / Homozygous)

Why it matters: In autosomal recessive inheritance, when each parent is a carrier (while both appear healthy), the chance of their child being born with the disease is 25% in each

Go to term →

VUS (Variant of Uncertain Significance)

This is the situation where the test has detected a change in the DNA, but the role of this change in the development of disease is unconfirmed.

Go to term →

How to Read a Genetic Test Result (Positive / Negative / VUS)

A genetic test result falls into three main categories

Go to term →

Types of Genetic Tests

A genetic test is a type of medical test that detects changes in genes, chromosomes or proteins. Today there are more than 77,000 genetic tests available.

Go to term →