Interpreting post-fertilization progression by visually grading embryos
Producing multiple eggs in an IVF cycle will ideally lead to having multiple embryos from which to choose. Your fertility specialist, together with highly trained embryologists, draws upon years of experience in evaluating embryonic quality and each embryo’s potential to grow into a viable pregnancy. Dr. James Douglas and the IVF Plano embryologists makes educated decisions based on the appearance and cell division of blastomeres in the time period after fertilization.
You may have surmised that grading embryos, assigning them an A, B or C, has the same associated weight as a classroom grade. You hope for an A and regret to receive a C. The goal is to transfer—or cryopreserve for the future—good quality embryos during your final stage of the IVF cycle.
Patients ask us how we arrive at a decision when grading embryos. Today, we have new methods that use time-lapse photography and computer software, but we also employ the established method of visually grading embryos with the naked eye.
What’s involved in visually grading embryos
Embryologists examine each embryo under a microscope to track the growing number of cells, or blastomeres. We do not want to see cell fragmentation, or uneven division withing the embryo. We do, however, expect to see cell growth double each day or so.
- When the sperm fertilizes the egg, a single cell organism called a zygote is formed.
- On or around Day 2, the embryo will develop into a 4 cell organism.
- On or around Day 3, the embryo will develop into a 8 celled organism.
- On or around Day 5, the embryo will develop into a blastocyst and forms what will become the placenta (trophectoderm) and what will become the fetus (inner cell mass).
A steadily growing embryo, with cells that look uniform and solid, has a good chance for implantation. We also want to see a solid outer shell (zona) and translucent cytoplasm.
This is an example of a Grade A Embryo on Day 2 and Day 3:
Our Plano IVF lab protocols track embryo growth to establish subtle changes that if overlooked could result in transferring an embryo that only appears to be healthy.
Beyond outward appearances: Looking at PGD
Preimplantation genetic diagnosis, or PGD, enables fertility specialists to ascertain the precise characteristics of an embryo. The process removes a small sample of cells from the developing embryo and extracts genetic information about how the chromosomes align and balance. Visually grading embryos is an alternative to PGD, but it does not provide as detailed a picture.
Your IVF cycle will unfold with precision and attention to detail. Dr. Douglas invites you to participate in each decision-making opportunity by asking questions and learning more about each phase, from ovulation induction and trophectoderm biopsy to embryo transfer.
Contact us for a consultation with Dr. Douglas, named a Top Doctor in Plano and Frisco. We specialize in the advanced reproductive technology of IVF.