PGT-A Testing vs. Sperm Sorting: What's the Difference?

In the IVF world, advanced technology makes gender selection possible for the families who wish to choose the gender of their babies. Today, patients undergoing IVF can screen embryos to determine their gender, and transfer only the embryo(s) with the desired gender into the uterus for implantation.  This can be done for any number of reasons, and is often asked about at varying parts of the IVF journey.

One of the more common methods that is frequently asked about is Sperm Sorting. This article will touch on this technology as well as PGT-A testing for gender selection.

What is Gender Selection in IVF?

Gender is determined by the individual sperm that fertilizes the egg.  Chromosomally normal babies get 22 chromosomal pairs and a sex chromosome from each parent. Females will only have X sex chromosomes, and so each of her eggs will have 22 chromosomal pairs and an X sex chromosome. Males carry both an X and Y sex chromosomes, and each individual sperm will carry 22 chromosomal pairs and have an X on one side with a Y on the other. 

A couple may choose to select gender to prevent certain genetic diseases or to promote family balancing.  If one parent is a genetic carrier for sex-linked disorder, for example, his or her male offspring are likely to be affected from the disorder while female offspring are likely to be genetic carriers.

What is the purpose of Sperm Sorting?

In short, sperm sorting is a gender-selection technique that improves a couple's chances of choosing their preferred embryo's gender. Its intent is to separate the sperm that contains the genetic material for the X chromosome from the Y chromosomes to allow for gender selection. 

What Are the Methods of Gender Selection?

PGT-A Testing 

PGT-A (PGS) tests all 23 pairs of chromosomes for structural/numerical abnormalities. IVF with PGT-A has a greater than 98% accuracy in identifying the gender of each embryo tested. PGT-A can also determine which embryos are genetically abnormal and eliminate chromosome-related diseases like down syndrome. 

Sperm Sorting 

As stated above, sperm sorting is a technique that helps a couple decide a preferred gender. Some specialists believe that sperm that carry an X chromosome contain more genetic material than those that have a Y chromosome. When stained with specific fluorescent dyes, the X chromosome sperm appear to glow more intensely than Y chromosome sperm when viewed with ultraviolet light. The larger X chromosome absorbs more dye than its smaller Y chromosome counterparts. All sperm sorting methods leverage the difference in genetic material in different ways to separate individual spermatozoa in each sample into X and Y groups. 

However, we would like to mention that the success rates of various sperm sorting techniques are debatable. Some published studies shows that sperm sorting has a 70% - 80% chance of successfully selecting a female, and 60% - 70% for selecting a male. However, this might not be accurate and  agreed upon by all physicians. The techniques have been improved over time, but many areas of this method have not been well studied. There are also concerns about potential DNA damage and the impact on embryo development, hatching, and implantation success rates. Therefore, not all IVF specialists would recommend sperm sorting as a gender selection method.

Does PFCLA offer Sperm Sorting? 

PFCLA does not presently offer sperm sorting as a method of gender selection. Because the accuracy of sperm sorting is not well documented in the medical field, when it comes to gender selection, we suggest an alternative approach with PGT-A (PGS) testing as mentioned above.  PGT-A (PGS) testing will lead to the most optimal outcome of healthy embryos and accurate results of the gender information. 

If you have further questions, please do not hesitate to contact us  today.