The Pacific Fertility Center (PFC) reports very high pregnancy rates in its patients undergoing in vitro fertilization (IVF) using a new type of pre-implantation genetic testing called comprehensive chromosome screening (CCS). PFC began employing this exciting new tool in the fall of 2011, thanks to advances in molecular genetics and embryology.
With CCS, PFC's average implantation rates are 76 percent in women under the age of 40 and 60 percent in those older than 40. Overall, two-thirds of PFC patients receiving an embryo selected with CCS have resulted in a pregnancy confirmed by ultrasound.
CCS uses advanced microarray technology to test chromosomes with more than 99 percent accuracy. It allows selection of high-quality embryos for transfer, which not only improves implantation rates, but also reduces miscarriage rates. And, because CCS reliably identifies high-quality embryos, patients don't have to "hedge their bets" by having several embryos transferred at one time. Therefore, CCS also helps reduce multiple pregnancies and the risks that accompany them.
In the past, it was difficult to know which embryos were of high quality. An embryo could look fine under the microscope, but have an abnormal number of chromosomes. In fact, when researchers examine the DNA within embryos, they find that 40–90 percent of normal-appearing embryos are genetically abnormal.
Earlier types of pre-implantation genetic testing had significant shortcomings. These tests involved removal (biopsy) of cells at an early embryo stage. Sampling of single cells at an early stage was not necessarily representative of the whole embryo, and thus certain abnormalities could be missed. Early biopsy also appeared to be detrimental to the health of some embryos.
With highly sensitive CCS techniques, it is now possible to test all 23 pairs of chromosomes in an embryo at a later stage, reliably and safely learning the exact number of chromosomes. This makes it possible to identify embryos with normal genetic structure and thus select the highest-quality embryos out of a group for transfer.
This is how it works at cutting-edge facilities such as the Pacific Fertility Center:
After conventional in vitro fertilization, embryos are grown to day five or six, the blastocyst stage. This is when all cells are more likely to be consistent and embryos are more resilient to biopsy. An embryologist safely removes a few cells from the early placenta and sends them to a genetics lab where chromosomes are counted. This takes about a week. In the meantime, the embryologist vitrifies (rapidly "freezes") the embryos and stores them for later transfer into the uterus.
The embryologist can then transfer an embryo(s) with a normal number of chromosomes – improving the chances of pregnancy, reducing the risk of miscarriage, and helping to produce one healthy baby at a time.
About Pacific Fertility Center
Pacific Fertility Center is an international destination for male and female fertility treatment and care. It provides an extensive array of fertility treatment options ranging from intrauterine insemination (IUI), intracytoplasmic sperm injection (ICSI) and in vitro fertilization (IVF) to cutting-edge technology such as vitrification and genetic testing of embryos. For more information: www.pacificfertilitycenter.com.