Matching

Finding/Donating Embryos

If you select a clinic or agency path, they will be responsible for sending you profiles of potential matches. Oftentimes for open adoption they require you to view one profile at a time, making a decision on a family before viewing any other profiles. Some clinics with anonymous programs will send recipients multiple profiles matching their desired guidelines.

If you choose to privately locate your donor/recipient, then there are several resources available to ease the process for you. Matching websites or embryo registries allow you post profiles and view profiles at your own pace.

 

Choosing Embryos

There are many factors to consider when selecting a set of embryos to adopt. Many families have preferences on variables such as race, eye/hair color, height, and educational background of donors. If you have selected a Closed or Anonymous adoption, variables concerning the embryo’s health and likelihood of pregnancy will be important to you. In addition to these, variables concerning the donor family will be important to those who have selected an Open or Semi-Open adoption. These could include a donor’s location, religious beliefs, expected level of communication, and philosophy on embryo adoption.

When considering a set of embryos, it is important to understand the impact of the donor’s maternal age, history of infertility, and embryo grading.

Maternal Age of Donor

The older the maternal donor is, the more embryos a doctor will allow to be thawed at one time. The following guidelines are recommended for fresh embryo transfers by SART. One additional embryo may be transferred if the donors/recipients have experienced a history of failed transfers or have a less favourable prognosis.

MATERNAL AGE OF EGG DONOR:	Less than 35	35-37	38-40	41+
Favorable Cleavage Embryos (Day 2-3)	1-2	2	3	5
All Other Cleavage Embryos (Day 2-3)	2	3	4	5
Favorable Blastocysts Embryos (Day 5-6)	1	2	2	3
All Other Blastocysts Embryos (Day 5-6)	2	2	3	3

Fertility of Donors

Independent of Maternal age, there are several factors that have been associated with a favourable prognosis:

• The donors were successful on their first round of IVF.
• They were successful in achieving pregnancy on every round of IVF they completed.
• Embryos remaining from IVF cycles were good enough quality to freeze.
• Pregnancy has been achieved by frozen embryos in this IVF batch.

Embryo Grading

Day 5 “Blastocysts” Embryos

Many clinics use different grading systems to score the embryos. It is important to read the embryology report to determine how their particular grading system works.

The commonly used Gardner blastocyst grading system assigns 3 separate quality scores to each blastocyst embryo. For example, if an embryo is graded a “5AB”:

The number “5” would describe the Blastocyst development stage. This number describes the progress the embryo has made towards expansion and hatching. The goal is for the embryo to be a “6” so that it can easily implant, however, the embryo can continue to expand and hatch in the uterus after a transfer.

Expansion grade	Blastocyst development and stage status
1	Blastocoel cavity less than half the volume of the embryo
2	Blastocoel cavity more than half the volume of the embryo
3	Full blastocyst, cavity completely filling the embryo
4	Expanded blastocyst, cavity larger than the embryo, with thinning of the shell
5	Hatching out of the shell
6	Hatched out of the shell

The letter “A” would describe the status of the Inner cell mass (ICM) score, or quality. This is the part of the embryo that will become the baby. Just like a school grading system, an “A” is considered more preferable to a “C”.

ICM grade	Inner cell mass quality
A	Many cells, tightly packed
B	Several cells, loosely grouped
C	Very few cells

The letter “B” would describe the status of the Trophectoderm (TE) score, or quality. This describes the appearance of the cells on the perimeter of the embryo.

Day 3 “Cleavage” Embryos

There are many embryo grading systems that differ in how they assign grades and in whether a low number grade indicates the best or the worst embryo. It is important to clarify what scoring system was used when they were originally evaluated. Day 3 embryos are graded based upon their appearance.

•  Cell number (are they growing?) Embryos should be at 2 to 4 cells at 48 hours after egg retrieval and preferably about 7 to 10 cells by 72 hours. The cells in an embryo are also referred to as “blastomeres”.
• Cell Regularity (are the cells the same size?) Generally speaking, the more identical the cells are to one another – the better.
• Degree of Fragmentation (are pieces chipping off the cells?) Fragmentation occurs when portions of the embryo’s cells break off. It is preferable to have little or no fragmentation, however, it is quite common and many beautiful babies have resulted from implantation of embryos with fragments. Embryos with more than 25% fragmentation are said to have a low implantation potential.

Special Consideration Embryos

These embryos have extenuating circumstances that need to be considered in the selection process. Sometimes single embryos are placed in this category because they are more difficult to find a family for. Oftentimes there has been an instance of genetic abnormality, special need, miscarriage, or birth defect in a biologically related sibling.