Archive for February, 2012

How Does EDI Decide to Exclude Potential Embryo Recipients?

Dr. Craig R. Sweet


By: Craig R. Sweet, M.D.
Reproductive Endocrinologist



There are times when we need to exclude patients when they contact Embryo Donation International (EDI) to become an embryo recipient. While not an easy decision or discussion, I thought it was time to explain our rationale when needing to, at least temporarily, exclude potential embryo recipients.

In a way, the blog we recently wrote on the ranking of potential embryo recipients dovetails into this discussion. In this blog, we described what we thought was an appropriate ranking system prioritizing those patients with the greatest need.

Our discussion here focuses on the patients who apply but who are never ranked because EDI feels they should be excluded because of any number of the reasons described below.

Excluding Potential Embryo Recipients Due to Maternal Risks

The decision to exclude a patient from embryo donation is really, in some ways, no different than the decision we have to make with other infertility patients.

Relative contraindications to pregnancy

There are occasions when certain conditions should probably be corrected before pregnancy takes place since pregnancy will often worsen or complicate the condition. Examples may include gallbladder disease and ovarian cysts or surface uterine fibroids that are five+ centimeters in average diameter. Treating these problems once pregnancy is established is very difficult, so it may be best to control the situation while we still can and correct the potential problem first before conception.

Strong contraindications to pregnancy

Patients who would be at significant risk of illness or even death should pregnancy occur include those suffering from cancer, poorly controlled systemic lupus, pulmonary hypertension or diabetes, to name a few important disease states.

Infrequently we have to be a bit paternalistic and say “no,” understanding that we may cause great harm to our ill patients by assisting them to become pregnant.

Excluding Potential Embryo Recipients Due to Risks to the Embryo/Fetus

The trickier decisions involve those patients where the potential for delivery of a live child is measurably reduced. Patients with decreased embryo implantation rates and those who are at an increased risk for spontaneous loss or at an increased risk for premature delivery/stillbirths fall into these categories.

Some of these examples are listed below:


Decreased implantation

Increased risk of spontaneous loss
(< 20 wks. gestational age)

Increased risk of significant prematurity or stillbirth

Uterine cavity distorting fibroids or polyps


Uterine fibroids 2+ cm in size located within the uterine muscle



Damaged uterine cavity with a thin endometrial lining



Hydrosalpinx where tubal fluid may flow back into the uterus



Unexplained recurrent pregnancy loss


Uncontrolled medical conditions (e.g., hypertension, diabetes, renal disease, autoimmune disease)



History of an incompetent cervix



Persistent history of premature births


Untreated pre-diabetes




Obesity or morbid obesity*




* The effects of obesity or morbid obesity with regards to implantation rates and spontaneous loss rates are controversial.

The “Grey” Exclusion Zones

Out of the list above, one of the most difficult categories involves those patients who are obese or morbidly obese and their scalepotential reduction in implantation rates and increased spontaneous loss rates. Some articles show a significant reduction in implantation rates and an increased risk of spontaneous loss while others show contradictory results. While a comprehensive review of this topic goes beyond the scope of this blog, I believe there are a few things we understand:

  • Patients with glucose intolerance and insulin resistance, regardless of weight, are at a higher risk of developing gestational diabetes during pregnancy and the potential complications associated with this disease.
  • Patients who are obese or morbidly obese are clearly at risk during pregnancy for a host of issues, including preeclampsia, hypertension, large for gestational age babies, prematurity, stillbirths, gestational diabetes, Cesarean section deliveries and the risks associated with these surgeries.

There is only one preliminary study specific to embryo donation that did not show a consistent decrease in pregnancy rates as weight increased (Body Mass Index: BMI) but the trends were present suggesting an average reduction in overall pregnancy rate of 33% for obese and morbidly obese patients with a BMI of 30 or more. (Finger R., et al. 2011) We await the detailed publication of this important study to better understand this issue.

Weight loss is terribly difficult for patients and takes a great deal of time. Sometimes surgery, such as a gastric band or intestinal bypass surgery, may be the best option. These issues are the thorniest to decide, with pressure applied by potential embryo recipients who do not fully understand how their weight may contribute to failed implantation or pregnancy loss, though it certainly places them and their unborn offspring at greater risks during the pregnancy.

Surrogacy as an Option When Material/Embryonic/Fetal Risks are Too High

Some of the issues discussed in this blog can be treated. Then the potential embryo recipient can be moved out of the exclusion zone. Some of these issues are not treatable, so options such as surrogacy and/or adoption may be better alternatives.

While some embryo donation programs refuse to allow surrogacy, EDI feels this is an excellent alternative. For example, is it ethical for EDI to ask that the patient with asymptomatic uterine fibroids, which may significantly reduce implantation or increase pregnancy loss rates, be surgically removed in a patient who fears surgery? Is gestational surrogacy a better alternative?

In Summary

We do not mean to be cruel or judgmental but are forced to make difficult decisions regarding the acceptance or exclusion of embryo recipients. We owe it to the potential embryo recipients to give them the best chance possible, understanding there are medical conditions that may severely impair their chances for success. We owe a debt of gratitude to the embryo donors and take seriously the responsibility of finding a healthy patient for their embryos  hoping to maximize the chances that the embryos will survive and thrive. Lastly, and certainly not least, we owe it to the embryos to make certain they have the best chance possible.

Unfortunately, we sometimes have to make the difficult decision to exclude a potential embryo recipient, at least temporarily, until the medial concerns are remedied or certainly improved.


Finger R, et. al. Obesity and the ability to achieve pregnancy in embryo donation. Fertil Steril 2011;96(3)-S172.

Parent via Egg Donation – Parent via Embryo Donation

Marna Gatlin of PVED

Marna Gatlin of PVED


Exploring what we know – Marna Gatlin, Founder Parents via Egg Donation and guest blogger

I was asked recently what I thought about embryo donation vs. egg donation. Is a parent via egg donation the same as a parent via embryo donation?  What do they have in common?  Or are they very different?

My knee jerk reaction was “Well doh, of course they are the same.  They are both embarking upon a unique journey to become parents right?”

When I thought more about it, the word “versus” jumped out at me.  Did the individual asking the question really mean “versus” as in against, or in contrast to?

Are the two mutually exclusive?

When I think of egg donation and embryo donation, I think about the word “AND” – I don’t think of it as an either or.  Both are just different ways of either growing or adding to your family.

Some approach embryo donation with great trepidation because they worry about the bonding process, or about the explanation or story they will be sharing with their child. The reality is – the path might be different but at the end of the day the goal is the same – you are becoming a parent.

Let’s delve a little deeper.  If you receive a donor egg, the genes of your baby are going to be combined with the genes of your husband (or partner) and those of your egg donor. Or if you are a single mother, or women in a same sex relationship, the donor egg will be combined with donor sperm.  You will probably undergo what we call a fresh embryo transfer.  You will carry that baby for nine months and then deliver that baby.  Women often wonder if there’s a down side to carrying a baby that is not genetically related to them.  You know this is an age old question that’s been asked and answered since the early 80’s when the first donor egg child was conceived, carried, and delivered. I can tell you as a parent via egg donation myself that it doesn’t matter.  I carried my son for nine months.  The bond I created with him is rock solid, loving, and he’s my son. The lack of genetic connection simply doesn’t matter.  Not one iota.  The very same thing happens with embryo donation recipient parents who are receiving truly a meaningful gift of life.

The most beautiful aspect of embryo donation to me is that embryos that are being placed for donation are done so purposely. These are embryos that the donating parents know have created amazing children who are loved, honored and cared for.  These donating parents want to make sure their embryos are donated to a home that will love, cherish and honor the resulting children as they would. Regardless of whether an individual has a child via egg donation or embryo donation, the fears of parenthood almost always focus on the unknowns. And here’s a secret:  they are also experienced by those who are conceived naturally.  Moms and Dads all over the world have the same worries about parenting as do parents via egg donation and embryo donation.

Parents via egg donation often ask questions such as:

  • Am I going to screw up my child?
  • Will my child love me?
  • How am I going to relate to my child?
  • Will my parents and other family members accept my child?
  • How and when will I share information about their conception?

When we look at embryo donation the questions that we find unique to embryo donation are:

  • Are we protected legally, can the donating parents come back and claim our child in the future? (The answer is NO, they cannot.  That’s why it’s important to have a clear legal contract.)
  • Will my child have access to information about his or her health in the future?
  • Will my child have siblings and if so, will they have the opportunity to know them?
  • Will my child or children see me as their real parent?
  • How will I explain this to my family or friends?
  • What about stupid comments from those around me?
  • How and when will I share the information about my child’s conception with my child?

To me there is no difference between being a parent via egg donation or a parent via embryo donation.  The end result is the same.

At the finish line we are simply Mom and Dad.

Marna Gatlin
Parents via Egg Donation | marna(at)

A little bit about Marna…

After many years of struggling with infertility, PVED founder Marna Gatlin discovered that the technology to have a child through egg donation was available. She was curious, excited, and above all, hopeful that this process might be the conduit to finally achieving her lifelong dream of becoming a parent.

Marna ensures that all the needs of egg donor recipients are met, maintaining a high standard of ethics and confidentiality. Marna advocates and assists recipient parents, helping them arrange for the highest quality patient care, wherever in the world they reside. Her experience and knowledge related to the complex emotional and physical needs of individuals dealing with infertility makes her an essential asset PVED.

As a previous recipient, Marna is uniquely qualified to provide caring and timely services. Marna is truly dedicated to compassionately guiding couples experiencing infertility through their treatment process.

Marna is joined by several dedicated and knowledgeable support staff that all work together clearly dedicated to see the success of PVED. These include clinical psychologists, reproductive endocrinologists, attorneys, as well as a talented business and public relations team.

Marna attended Eastern Oregon University and Portland State University majoring in Business, Psychology, Social Science, and is a member of the American Society of Reproductive Medicine (ASRM), the European Society of Human Reproduction and Embryology (ESHRE) and the Society for Assisted Reproductive Technology (SART). Marna, a writer, is married, has a son, and does some of her best thinking and creating atop of her John Deere tractor mowing and cultivating her back forty.

Final Post in Mini-Series: Thawing/Warming Embryos

In the first two segments of this series, we discussed embryo grading and cryopreservation (1 – Do these embryos make the grade? and 2 – Embryo Cryopreservation: An Easy to Understand Review). This final segment in the series will examine the process of thawing or warming of embryos for transfer.

In Review…

Let’s begin with a short review of the previous blogs. You will recall that we discussed two methods of embryo cryopreservation, slow freezing and vitrification. Both methods require that the cells of the embryo have as much water removed as possible and that cryoprotectants, materials that protect the cells during freezing, be forced into those cells to reduce ice crystal formation. Slow freezing uses a controlled rate freezing instrument that slowly lowers the temperature to well below freezing to avoid the formation of ice crystals. Vitrification is a method in which embryos are plunged directly into liquid nitrogen and immediately turned into a glass-like substance, essentially cooling the embryos so quickly that ice crystals do not even have time to form.

Cryopreservation Storage Containers

One topic not covered in the freezing blog was the type of containers used to hold the embryos. Slow freezing, in most cases, uses straws or vials to hold the embryos in a small amount of solution called media. Vitrification uses many different storage devices to hold the tiny embryos, which cannot be seen without a microscope. These devices commonly include various types of straws, nylon loops or electron microscope grids, just to name a few.

How Often do the Cryopreserved Embryos Survive?

It is expected that about two-thirds of embryos cryopreserved via a slow freeze technique will survive thawing (Son and Tan, 2009) and the embryos that do not survive are most likely genetically abnormal. For embryos that are vitrified, the rapid cooling/warming process seems to work better, with about 80-90% of the embryos surviving. For this reason, vitrification is becoming more popular for cryopreserving both eggs and embryos.

How Many Embryos Should Be in Each Container?

Ideally only one or two embryos should be packed into each storage container. By packaging one embryo per container, the embryologist can thaw or warm only the exact number of embryos to be transferred without having any left over. For example, if a patient wants to have two thawed cryopreserved embryos transferred and they have a total of five embryos each frozen in separate containers, the embryologist will thaw/warm one container at a time until just two healthy embryos are recovered. If, however, the same five embryos were packaged in two containers with three embryos in one and two in another, the embryologist would probably first begin thawing/warming the container with three embryos. Should all of the embryos survive, there is one excess embryo that would need to be transferred, refrozen or discarded. While recent studies have indicated that freezing embryos a second time can result in a pregnancy, particularly when using vitrification, it is ideal to only thaw the exact number of embryos that we want to transfer and not one embryo more. (Kamasko, Y., 2009).

How are the Embryos Thawed/Warmed?

Ice crystal formation is also the enemy when thawing embryos, just as when cryopreserving them,. As embryos warm from -196°C (-321°F) toward 0°C (32°F), ice crystals may again form and damage the cells. We use the following techniques to rapidly warm/thaw both slow frozen and vitrified embryos in an attempt to avoid ice crystal formation:

  1. For embryos frozen by the slow freeze method, the straws or vials are removed from the storage tank and held at room temperature for 30-60 seconds, allowing the embryos to warm only slightly. The storage container is then plunged into 37°C water, completing the thawing process quickly enough so that the ice crystals don’t have a chance to form.
  2. Vitrified embryos are taken out of liquid nitrogen, with the container then plunged directly into warming media that is either at room temperature or 37°C, depending on the method used to vitrify the embryos. Once again, the ice crystals simply do not have enough time to form.

Once the embryos have been thawed/warmed, the cryoprotectants that replaced the water in the cells must be removed and balanced solutions placed back into the cells. To accomplish this, embryos are moved from small bath to small bath with varying concentrations of water and other substances. As the cryoprotectants are removed, the cells fill with water containing the nutrients and growth factors needed for cellular recovery. Once the embryos have been thawed/warmed, they are placed in the incubator in supporting culture media for two to twelve hours to allow the cells to continue equilibration prior to transfer. If we are thawing embryos that were frozen early, we may even grow the embryos for a few days so that we transfer the fewest healthy embryos we need to achieve a successful pregnancy.

Are There Other Factors That Influence the Survival of Cryopreserved Embryos?

While ice crystals play a big role in the survival of embryos, they are far from the only concern. Embryo survival rates vary for many reasons including;

  1. Embryo quality: Poor quality embryos freeze and thaw poorly. Poor early development of an embryo suggests that the embryo is in the process of dying and such embryos should probably not be cryopreserved.
  2. Freezing media and cryoprotectant “recipes“: Some recipes are potentially better than others and each laboratory has to find which works best. What works well for one, may not be the best for others.
  3. Laboratory techniques: Laboratories must have an excellent quality control program to assure they are following the steps involved in freezing/cooling and thawing/warming the cryopreserved embryos precisely.
  4. Embryologist variability: As with all techniques that involve humans, some seem to do a better job than others. There is no substitution for careful training and experience.

In Closing…

We hope this series has given you a glimpse of what is involved in grading, freezing/cooling and thawing/warming your precious embryos. Cryopreserved embryos give patients the option to build their families in a cost effective manner. Without cryopreservation, embryo donation would really not be possible.

Corey Burke, B.S, C.L.S.
Laboratory Supervisor
Embryo Donation International


Kamasko, Y. The efficacy of the transfer of twice frozen-thawed embryos with the vitrification method.  Fertil Steril 2009;91:383-386.

Son, W.Y., and Tan, S.L. Comparison between slow freezing and vitrification for human embryos. Expert Rev. Med. Devices 2009:6(1),1-7