Pre-implantation Genetic Screening (PGS) using a Trophectoderm Biopsy Available At The New Hope Center
Only a select number of IVF centers have the ability to perform a Day 5, trophectoderm biopsy. With its continuing leadership in technology, New Hope is one of those centers.
Thanks to advances in assisted reproductive technologies, Dr. Robin and Dr. Perez are able to offer couples genetic screening of embryos prior to placing them into the uterus during an in vitro fertilization (IVF) cycle. This method of embryo screening is now commonly referred to as pre-implantation genetic screening or pre-implantation genetic diagnosis.
Pre-implantation genetic screening (PGS) refers to the general testing of the genetic chromosomes and is most commonly used to screen for Down's syndrome (trisomy 21).
Pre-implantation genetic diagnosis (PGD) refers to testing for a specific genetic disorder, such as cystic fibrosis.
There are various techniques that can be used for getting genetic material from an embryo, and more recently trophectoderm biopsy has been shown to be beneficial.
Trophectoderm BiopsyOnce an embryo has reached the blastocyst stage (typically on Day 5) a trophectoderm biopsy can be performed.
An advantage of a trophectoderm biopsy, is that approximately five cells are removed for analysis rather than one cell, which is the case with other embryo biopsy methods. By increasing the number of cells removed for genetic analysis, accuracy also improves, making trophectoderm biopsy a more reliable form of pre-implantation genetic screening (PGS).
When The New Hope Center performs a Day 5 biopsy, the embryo has matured to the blastocyst stage, and cells have multiplied to over 100. Inside the egg's protective shell (zona pellucida), two different types of cells serve two different purposes:
By the time an embryo reaches the blastocyst stage, cells of the embryo have differentiated into cells that are going to become the fetus and cells that are going to become the placenta.
The New Hope Center's skilled embryologists tap through the egg's outer shell so that a small proportion of trophectoderm cells begin to push through the microscopic opening.
On Day 5, these cells are removed and sent off to our reference lab for genetic testing. At the same time, all of the tested embryos are flash-frozen, or vitrified, for safekeeping until it's time to plan the couple's embryo transfer in a future month.
The cells that are removed from the embryo make up the placenta, not the baby, and their removal will not affect development.
Transfer of Embryos after Trophectoderm BiopsyWithin a few days, Dr. Robin and Dr. Perez will know the results of the trophectoderm biopsy and will review the results with you, relaying the normal of many embryos with normal genetic chromosomes and the number which are abnormal. Couples are then able to choose which embryos to transfer into the uterus. The embryo transfer can usually occur during the female's next menstrual cycle.
ApplicationsPreimplantation genetic screening/diagnosis is not routinely recommended for couples undergoing IVF, as only a small percentage of patients can truly benefit from this technology. When PGS or PGD are indicated, your physicians at The New Hope Center will recommend Day 5 trophectoderm biopsy.
Reasons why Day 5 Trophectoderm Biopsy is preferential.
- Better technology
- Less False Positives
- Lower risk of misdiagnosis
- Less damage to the embryo
- Lower risk of no signal from the embryo (no diagnosis)
Should you require PGS/PGD, it's important to make sure the clinic you work with has the capability and experience to perform a Day 5 Trophectoderm Biopsy