When the first successful pregnancy resulting from female egg donation occurred in 1984, doctors initially planned on using the treatment only for women who had experienced premature ovarian failure. Recognition of this technique's increased fertility potential has allowed implementation of donor eggs to be used today in many other situations, including:
The Center for Assisted Reproduction has the resources to perform every step of the egg donation, fertilization, and implantation processes. If you and your partner are considering using donor eggs to conceive, the information provided here will allow you to more fully understand the different steps of the process.
To determine whether you are a good candidate to receive donor eggs, you will need to meet with one of our physicians. This visit is typically done in person but for our international patients or those who live a significant distance from the center, it may be done by phone. A thorough infertility and medical history will be completed. A vital part of the preparatory phase of egg donation is a consultation with a psychologist. Since the decision to give birth to a child that is not completely genetically yours is a difficult one, your counseling will include your feelings about previously unsuccessful infertility treatment, whether your child will be told about his or her origins, and your opinion of egg donation in general.
A complete physical exam will be performed. The examination of your uterus will begin with a detailed pelvic ultrasound and may require a hysterosalpingogram (x-ray of the uterus), or hysteroscopy (viewing of the uterus with a tiny camera). You will be tested for infectious diseases such as HIV, hepatitis B and C, and syphilis. Recent Pap smear results should also be available for review by your doctor. Additional tests and screening may be required, depending on your age, ethnicity, and medical history.
Prospective recipients of donor eggs may choose a known donor, such as a close friend or relative, or an anonymous donor chosen from our egg donor database. There are pros and cons to either method. A known donor often provides a closer sense of kinship and a deeper knowledge of the donor's past health and lifestyle choices. If the known donor is a relative, this choice will strengthen the genetic linkage between the child and the parents. Known donation, however, may make disclosure issues for the recipient couple more problematic. An anonymous donor allows the parents to choose a female who already understands the egg donation process and will feel no need to have a relationship with the child after its birth.
If you choose an anonymous female from our egg donation database, you can rest assured that she has completed an in-depth questionnaire about her medical, personal, and obstetrical histories. She also will have had infectious and genetic screening to ensure that her donor eggs are as healthy as possible.
Genetic testing plays an important role in the evaluation and screening of potential egg donors. Certain genetic testing is done routinely by CAR on their donors. Caucasian donors undergo cystic fibrosis screening. African American donors undergo screening for sickle cell anemia. All donors undergo screening for Fragile X Syndrome.Below is a description of each of these disorders.
What is it?
Cystic fibrosis (or CF) is an autosomal recessive disorder that causes a chronic lung condition. Individuals with CF have thickened membranes in the lining of their lungs causing recurrent lung infections, which require lifelong medical care. CF can also cause pancreatic insufficiency. Intelligence is not affected. Males with CF are usually infertile due to congenital absence of the vas deferens.
Who is at risk?
The carrier incidence is approximately 1 in 29 Caucasians. Carrier status is much less frequent in Asian Americans (1 in 90), in African Americans (1 in 65) and in Hispanic Americans (1 in 46). Both the male and female (or egg donor) would have to be carriers in order for the offspring to be affected.
Sickle Cell Disease
What is it?
Sickle cell disease is an inherited disease of red blood cells, which can cause attacks of pain and damage to vital organs. It can lead to early death. There are several forms of sickle cell disease. The most common forms are referred to as SS (the child inherits two sickle cell genes), SC (the child inherits one sickle cell gene and one gene for other abnormal type of hemoglobin called “C”) and S beta-zero thalassemia (the child inherits one sickle cell gene and one gene for another type of thalassemia, another inherited anemia.)
Who is at risk?
In the United States most cases of sickle cell disease occur among African-Americans and Hispanics of Caribbean ancestry. About one in 400 African Americans has sickle cell disease. It also affects people of Arabian, Greek, Maltese, Italian, Sardinian, Turkish and Indian ancestry. One in 12 African-Americans has the sickle cell “trait”. They are as healthy as non-carriers, rarely having any health problems related to the trait. Sickle cell trait cannot change to become sickle cell disease. However, when two people with sickle cell trait have a child, their child may inherit two sickle cell genes and have SS, sickle cell disease. Readily available blood tests such as hemoglobin electrophoresis can identify people who have either sickle cell trait or a form of the disease. Additional information regarding sickle cell anemia may be obtained from:
The Sickle Cell Disease Association of America at www.sicklecelldisease.org
Fragile X Syndrome
What is it?
Fragile X syndrome is the most common inherited form of mental retardation Mental retardation ranges from borderline to severe, although most patients have moderate degrees of mental retardation. Other associated phenotypic abnormalities include autistic behaviors, macroorchidism in adult males, characteristic narrow face with a large jaw, and speech and language problems. The abnormal facial features are subtle and become more noticeable with age, making phenotypic diagnosis difficult, especially in the newborn. Affected females may have a more subtle phenotype, and it is sometimes hard to establish the diagnosis.
Fragile X syndrome is transmitted in a classic X-linked recessive fashion. However, the molecular genetics of the syndrome are complex. The disorder is caused by expansion of a repeated trinucleotide segment of DNA (cytosine-guanine-guanine) that leads to altered transcription of the fragile X mental retardation 1 (FMR1) gene. The number of repeats varies among individuals and has been classified into four groups depending on repeat size: unaffected, intermediate, premutation, and full mutation (see Table 1). A person with 61-200 repeats usually is phenotypically normal and is said to have a premutation. When more than 200 repeats are present, an individual has a full mutation that results in the full expression of fragile X syndrome in males and variable expression in females secondary to X inactivation. This condition occurs because the large number of repeats causes the FMR1 gene to become methylated and inactivated in these patients. The number of repeats and the status of gene methylation are determined by use of DNA-based molecular tests.
Who is at risk?
Fragile X Syndrome affects approximately 1 in 4,000 males and 1 in 8,000 females from a variety of ethnic backgrounds. Transmission of a disease-producing mutation to a fetus depends on the sex of the parent and the number of cytosine-guanine-guanine repeats present in the parental gene. Parents at risk for transmission of the disease are those who have the permutation or the full DNA mutation. When a female carries the premutation and the length of the repeat exceeds 90, premutation genes are much more likely to expand and result in the birth of an affected child. Women with an intermediate number of triplet repeats (41-60) rarely transmit a full mutation to their offspring, although there may be some continued expansion through the generations. Genetic counseling for intermediate results may be useful. Males may transmit the unexpanded premutation gene to their children, but expansion to a full mutation is extremely rare in the offspring of a male having the premutation gene. Typically, the children of a male premutation carrier receive the premutation unchanged; in children of female carriers. However, the premutation may expand during meiosis. Empirically determined risks are available for the purposes of genetic counseling.
Males and, to a lesser extent, females carrying a premutation are at increased risk for late-onset neurodegenerative disorder characterized by tremor and ataxia. However, additional research is needed to define the relative risk. In addition, women carrying a premutation are at increased risk (20-30%) for premature ovarian failure. If a woman has ovarian failure or an elevated follicle-stimulating hormone level before the age 40 years without a known cause, fragile X carrier screening should be considered to determine whether she has a premutation. Recent studies also have demonstrated an increased frequency of autism or autistic like behavior in children with a premutation.
What Can I Do If the Donor Is a Positive Carrier for Cystic Fibrosis or Sickle Cell Anemia and so is My Husband or Male Partner?
If the donor is anonymous (unknown to the couple), choose another donor who is not a carrier. In the situation of known egg donation, the couple could choose to go through the cycle using Preimplantation Genetic Diagnosis (PGD) to determine which embryos are affected by the genetic disorder prior to embryo transfer. For more information about PGD, please visit www.embryogenetics.com.
In an effort to assist our recipient couples in assessing the donor’s past family history and ethnicity on outcome; our donors undergo a consultation with a genetics counselor at UTSWMS, Karen Heller, MS, CGC . A copy of this evaluation is given to the recipient couple to aid them in deciding if they would like additional genetic screening of the donor. Recipient couples may choose to schedule an appointment with Karen Heller to address any potential concerns they may have regarding the genetic screening. Our Egg Donation Nurse Coordinator, Jennifer Leonard R.N., would be happy to facilitate scheduling an appointment for the recipient couple.
In preparation to receive donor eggs, hormones are given to both the donor and the recipient to synchronize the ovarian stimulation of the donor and uterine receptivity of the infertile woman. To synchronize your menstrual cycle with that of the donor, typically a hormone known as a gonadotropin releasing hormone agonist, or GnRH agonist will be administered to suppress your normal ovulatory timing.
Once the donor and recipient are synchronized, further medication is needed to continue the egg donation process. First, the recipient is placed on an estrogen replacement program to prepare her uterus to receive a fertilized embryo. Estrogen is introduced to the body via either an oral route or transdermally (skin patch).
Shortly after the recipient hormone therapy begins, the egg donor starts preparation for egg donation. She is given daily injections of follicle stimulating hormones (FSH) to stimulate her ovaries. These hormones will cause the ovaries to produce a greater number of mature eggs than would naturally occur.
The doctors at the Center for Assisted Reproduction carefully monitor the effects of hormones given to both the donor and the recipient to ensure that responses remain synchronized. For the four to six days before the donor eggs are harvested, these tests may be required every day for the donor. The recipient typically has one or two visits during the last week of donor stimulation.
After the donor has been placed under sedation, one of our physicians will remove the donor eggs using a thin needle inserted through the vagina and guided by ultrasound. The donor receives anesthesia via intravenous sedation to minimize any discomfort. This is administered by a physician who specializes in anesthesia. To ensure that the donor does not experience any negative effects from the harvesting procedure, she is asked to return to the Center for Assisted Reproduction for a follow-up visit about a week later.
On the same day that the donor eggs are harvested from the donor, the recipient's partner will provide a semen sample that is processed and used to fertilize the donor eggs. Once an egg has been fertilized with sperm, it becomes an embryo that is cared for in the laboratory for five or six days before it is transferred to the recipient.
The transfer involves up to two embryos (derived from donated eggs) to increase the chances of success. Your doctor will already have discussed with you the possibility of multiple birth when using egg donation. Excess embryos that are suitable for transfer may be cryopreserved for future use. At CAR, approximately 70 percent of couples undergoing egg donation cryopreserve or freeze extra embryos. The average number of embryos frozen per couple is 4.5.
Once the embryo transfer is complete, the recipient of the donor eggs will continue estrogen and progesterone therapy to maintain an optimal uterine environment. Most women will require these hormones for seven to eight weeks after the embryos have been implanted.
To learn more about the female volunteers in our egg donation program, or to find out if you are a good candidate to receive donor eggs, contact one of the program coordinators at the Center for Assisted Reproduction. Our caring staff and state-of-the-art facility will provide you with the support you need during this difficult time.
To learn more about donor eggs received through our female egg donation program, contact the Center for Assisted Reproduction to schedule a consultation.