PGS, Array CGH Testing in Tbilisi, Georgia

PGS, Array CGH Testing in Tbilisi, Georgia IVF Atlas Center

Patients researching genetic testing for IVF often come across the terms PGS and array CGH, sometimes used together as though they're a single technology. Understanding what each term actually refers to and how this approach compares to what's used in embryology labs today can help you have a clearer conversation with your treatment team about which testing option is right for your cycle.

What PGS Actually Means

PGS, or Preimplantation Genetic Screening, refers to testing embryos for the correct number of chromosomes before selecting one for transfer. It's a broad screening tool rather than a test for one specific disease it's designed to identify aneuploidy, meaning embryos with an abnormal number of chromosomes, which is a leading cause of failed implantation, miscarriage, and unsuccessful IVF cycles. In current clinical terminology, this same testing is now more precisely referred to as PGT-A, with PGS considered the older, informal name for the same underlying purpose.

What Array CGH Is

Array comparative genomic hybridization (array CGH) is one of the laboratory methods historically used to perform this kind of chromosomal screening. In simple terms, the technique works by comparing a sample of DNA taken from the embryo against a reference sample with a known, normal chromosome pattern. Differences in the intensity of fluorescent signals between the two samples reveal whether the embryo has gained or lost chromosomal material.

Array CGH represented a significant step forward when it was introduced, allowing labs to assess all 24 chromosome types (22 autosomes plus the X and Y chromosomes) in a single test, rather than screening only a handful of chromosomes at a time as earlier methods did.

How This Compares to Current Technology

In most modern embryology laboratories, including ours in Tbilisi, array CGH has largely been succeeded by next-generation sequencing (NGS) as the preferred method for PGT-A. NGS offers finer resolution, meaning it can detect smaller chromosomal segment abnormalities that array CGH may miss, and it's generally considered more effective at identifying mosaicism a condition where an embryo contains a mix of both normal and abnormal cells, which array CGH is more limited in detecting reliably.

That said, understanding array CGH remains useful, both because some patients arrive with test results or embryos from a previous cycle at another clinic that used this method, and because it helps illustrate how far embryo screening technology has evolved. If you have prior array CGH results, our team can review them and explain how they fit into your current treatment plan.

Who PGT-A Testing Is Typically Recommended For

Regardless of which underlying laboratory method is used, chromosomal screening is generally recommended for women of advanced maternal age, patients with a history of recurrent pregnancy loss, those who have experienced repeated unsuccessful IVF cycles, and couples looking to reduce the number of embryo transfers needed to achieve a successful pregnancy.

Making the Right Choice for Your Cycle

Because testing technology continues to evolve, the most useful step is a direct conversation with your embryology team about which method is currently used in your treatment cycle and why. If you have questions about PGS, array CGH, or how newer sequencing technology could apply to your specific case, our team in Tbilisi is glad to walk you through the details.