What Is Comprehensive Chromosome Screening CCS?

Comprehensive chromosome screening

CCS can benefit you in many ways.

By identifying embryos with missing or extra chromosomes, CCS reduces miscarriage and chromosomal abnormalities such as Down syndrome.

Selecting the healthiest embryos, CCS improves implantation, pregnancy rates, and the health of babies. It also allows for transfer of a single embryo, which reduces risks linked to multiple gestation.

Technological advances like CCS offer big benefit for people undergoing in vitro fertilization (IVF). Here’s a step-by-step description of how CCS is done:

Step 1: Stimulate
A woman takes special medication such as follicle simulating hormone (FSH), luteinizing hormone (LH or lo-dose hCG), or human menopausal gonadotropin (hMG). These injectable medications stimulate her ovaries to produce extra follicles.

Another drug—human chorionic gonadotropin (hCG)—triggers ovulation, the release of eggs from the walls of follicles.

Step 2: Retrieve
A day and a half (36 hours) after the ovulation trigger, a PFC physician retrieves eggs once they have reached just the right level of maturity. This is done using a needle inserted under ultrasound guidance through the top of the vagina into the ovary. Retrieval is performed under sedation.

Step 3: Fertilize
The eggs are immediately placed in an incubator. In the PFC laboratory, an embryologist fertilizes the eggs with the father’s or donor’s sperm—produced fresh on the day of egg retrieval or frozen ahead of time.

Step 4: Culture
Now embryos, fertilized eggs, develop in culture. Some will continue to grow. Any that fail to develop will be discarded.

Step 5: Biopsy
By the fifth or sixth day—the blastocyst stage—embryos have developed more than 100 cells, including the early placenta. An embryologist removes a few cells from the early placenta. Using an advanced freezing technique called vitrification, embryos are then stored in PFC's lab.

Step 6: Analyze
The removed cells are sent to a specialized genetics lab for chromosomal analysis. Here, lab technicians count the number of chromosomes in each embryo.

Step 7. Transfer
Although results return within a week, transfer waits until a following cycle 1-2 months later, when the uterine lining is once again receptive to implantation. The embryo identified as the highest quality is then warmed and transferred to the uterus.

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