Embryo Quality2024-03-12T15:37:05-06:00

Embryo Quality and Fertility

The quality of your embryos is one of the most important factors in your fertility. CCRM’s state-of-the-art labs and skilled embryology team help to ensure that we are creating the best quality embryos to improve your chance of in vitro fertilization (IVF) success.

Age & Embryo Quality

Many women realize that it becomes more difficult to achieve a pregnancy as they get older, but they don’t know why this is the case. As a woman ages, not only does her egg supply decrease, her egg quality rapidly declines after the age of 35, leading to an increased risk of fertility and chromosomal issues. (Read more about Eggs and Your Fertility.)

At the age of 30, 70% of a woman’s eggs are chromosomally normal. At 35 years of age, about 60% of a woman’s eggs are chromosomally normal. By the time a woman reaches 40, about 35% of her eggs are chromosomally normal.*

Unfortunately, chromosomally abnormal eggs will develop into chromosomally abnormal embryos following fertilization. Most chromosomally abnormal embryos will either fail to implant in the uterus or will result in miscarriage. In more rare instances, the chromosomally abnormal embryos may result in chromosomal disorders, such as Down syndrome, extra copy of chromosome 21.

Comprehensive Chromosome Screening (CCS)

While there isn’t a diagnostic tool that can accurately detect the quality of your eggs, we can test embryo quality during IVF. With CCS (also known as preimplantation genetic testing for aneuploidy), we can assess whether an embryo is chromosomally “normal” (euploid) or “abnormal” (aneuploid). A normal embryo will have a total of 46 chromosomes – 23 chromosomes come from the woman’s egg and 23 chromosomes from the man’s sperm. An aneuploid embryo will have too few or too many chromosomes.

Pioneered at CCRM, CCS testing is performed on a few cells biopsied from a day five or day 6 embryo called a blastocyst. The cells are analyzed and only the chromosomally normal embryos with the correct number of chromosomes are transferred into the uterus or are frozen for future use. Transferring the chromosomally healthiest embryos during IVF gives our patients the best chance for success.

All CCRM labs run at the highest level of expertise with strict quality control, attention to detail and ongoing assessments. This includes our CCS lab that focuses on platform execution and data analysis to enable accurate chromosomal testing of IVF embryos. As part of our ongoing commitment to excellence, we routinely reconfirm the CCS result on chromosomally abnormal embryos (donated with patient consent) to better understand the incidence of chromosome abnormality and identify the chromosomally normal embryos. This is an extra step not taken by other labs.


During CCS testing, we may identify embryos that contain both chromosomally normal and abnormal cells (known as chromosomal mosaicism). CCRM has reported the lowest chromosomal mosaicism rates in the U.S. at less than 3% of all biopsied blastocysts across the CCRM network. This closely resembles the low incidence of chromosomal mosaicism (1-2%) diagnosed during prenatal testing of both natural and IVF clinical pregnancies and is a reflection of the high quality of our labs.

Embryo Culture in the Lab

CCRM lab teams continuously work to determine the best environment, technology and equipment to grow high quality embryos. Here are several ways in which CCRM is a leader in lab protocols and technologies:

Cutting-Edge Technology

Embryos grow best in a stable environment that attempts to mimic the conditions in the female reproductive tract. Minimizing environmental variation is important to avoid stressing the embryos and compromising their development. CCRM uses mobile incubators (modified premature infant chambers) to maintain consistent temperature (37°C), humidity and gas environment of the culture media (the fluid the embryo grows in) when handling embryos for routine procedures.

In many laboratories, when the embryos are observed or being worked on under a microscope, they are removed from the incubator and are simply set on a heated surface in room atmosphere. CCRM’s mobile incubators enable us to perform most of these tasks in the regulated and stable environment.

CCRM also employs custom air purification systems in every lab to ensure the highest air quality and rigorous environmental control to optimize embryo development. These systems not only filter out particulates, but control the levels of harmful volatile organic compounds (VOCs) and yield levels far below recommended limits in parts-per-billion.

Rigorous Quality Control

The majority of labs use culture media and contact supplies directly from the manufacturer and rely on the manufacturer’s quality control testing to ensure no toxicity exists. CCRM goes an extra step by implementing an additional level of quality control testing on all culture media and contact supplies. This extra testing entails using an ultrasensitive bioassay developed at CCRM to ensure culture media and contact supplies are not toxic to developing embryos. This is a step not taken by most IVF labs.

Day 7 Biopsy

Some embryos develop slowly and need an extra day to grow to the blastocyst stage, which is the stage when biopsy (removal of a few cells) is performed for preimplantation genetic testing (PGT). Many labs do not grow an embryo past day 5 or 6 since the process is both labor intensive and involves extra supplies and expenses. CCRM performs day 7 biopsy, when indicated, to ensure the patient has as many embryos available for biopsy as possible.

Second-Day ICSI

Intracytoplasmic sperm injection (ICSI) involves the direct injection of sperm into eggs. Typically, the eggs are retrieved and ICSI takes place on the mature eggs later the same day. However, sometimes the eggs need more time to mature and, in these instances, CCRM will perform “second-day ICSI” to ensure the patient has as many embryos created as possible. Many labs do not perform second-day ICSI since it is labor intensive and involves extra supplies and expenses, and they do not believe that it produces good quality embryos. At CCRM, we have observed chromosomally normal babies born from second-day ICSI and CCS.

Is it Time to See a Fertility Specialist?

If you are under 35 with regular cycles and haven’t become pregnant after 1 year, or if you are 35 or older with regular cycles and haven’t become pregnant after 6 months, it’s time to make an appointment with a reproductive endocrinologist. If you haven’t been ovulating, have irregular menstrual cycles or have had multiple pregnancy losses, you should seek fertility care as soon as possible.

*Source: Dr. Mandy Katz-Jaffe, Scientific and Genetics Director for CCRM Fertility, Andrea Rodrigo BSc, MSc (Embryologist), Mark P. Trolice MD, FACOG, FACS, FACE (Reproductive Endocrinologist), Miguel Dolz Arroyo MD, PhD (Gynecologist), Sandra Fernández BA, MA (Fertility Counselor)

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