Gestational Surrogacy

What is Gestational Surrogacy?
To be a surrogate means to be a substitute. In regards to human reproduction, surrogates are women who carry a baby for a couple that cannot have a child, and will give the child to the couple when she delivers it. There are two forms of reproductive surrogacy:  traditional surrogacy and gestational surrogacy. A traditional surrogate is genetically related to the baby i.e., she provided the egg. (1). As you can imagine, today there can be (and has been) significant complications of such an arrangement and this form of surrogacy is no longer practiced by most centers, including CFS. What is practiced is gestational surrogacy. This is where a woman (gestational carrier) carries and delivers a baby for an infertile couple and is not genetically related to the child. Since pregnancy is not a benign condition (see discussion of risks below), the American Society for Reproductive Medicine recommends that this approach be used only when there are compelling medical reasons for doing so.

Medical Reasons for Gestational Surrogacy
Gestational carriers “may be used when a true medical condition precludes the intended parent from carrying a pregnancy or would pose a significant risk of death or harm to the woman or the fetus” (2). Examples of medical reasons include

  1. problems with the uterus
  2. the intended parent has a serious medical condition that makes pregnancy unwise
  3. biologic inability to conceive or bear a child

How does a Gestational Surrogacy treatment work?
With assisted reproduction, we need three things to achieve a successful pregnancy: sperm, eggs and a functional uterus. In this day and time, each of the components maybe “borrowed” from appropriately selected and screened sources. Sperm donation is borrowing sperm. Oocyte Donation is borrowing eggs. Gestational surrogacy is borrowing a uterus.

The first reported delivery from a gestational carrier was in 1989 (3) and our approach is not much different today, but fortunately, much more successful. At its most basic level, a gestational surrogacy treatment involves an In-vitrofertilization for the woman providing the eggs and preparation of a uterine lining of the gestational carrier. In the in vitro fertilization cycle, the ovaries are stimulated to produce several eggs (goal 10-20, but may be limited by the ovarian function). These eggs are retrieved from the follicles in the ovary, combined with the sperm in the laboratory and embryos develop over 3 to 5 days. While all of this has been going on, the endometrium (the uterine lining) of the gestational carrier has been prepared so that it will be receptive when the embryos are ready to transfer. Typically one embryo is transferred into the uterus of the gestational carrier. A pregnancy test is done 10-14 days after the embryo transfer. If the carrier is pregnant, she is kept on her hormonal regimen to support the pregnancy until the placenta is able to take over hormone production at about 8 weeks gestation.

What type of preparation is necessary for Gestational Surrogacy treatments?
There is a great deal of work to do before the Gestational Surrogacy treatment can be undertaken. These include:

  1. Psychosocial education of the intended parents (and eventually the gestational carrier) with our third party reproduction team and with a qualified mental health provider
  2. Screening and testing of the genetic parents. This can include complete medical screening, testing for infectious diseases, semen analysis and quarantine of the sperm, ovarian reserve screening of the egg provider
  3. Finding a gestational carrier
    1. Age: 21-45 years old
    2. Prior pregnancy experience: 1-5 uncomplicated pregnancies (3 or less if cesarean sections for delivery)
    3. Stable family environment
    4. Passes infectious screening,  medical screening and psychosocial evaluation
  4. Legal agreements and informed consent of all parties
    1. Both the couple and the carrier should have independent legal representation in this process.
    2. Both will need to be represented in the state where the baby will be delivered.
    3. We frequently work with with Mrs. Stephanie Brinkley on reproductive legal issues. Her web site address is:

How successful are Gestational Surrogacy treatments?
The first three days of human embryonic development is almost entirely an egg driven process. Thus, the qualities of the oocytes used in the gestational surrogacy treatment are the primary determinants of the outcome. Ovarian reserve testing is done on the individual providing the oocytes to assess quality of ovarian function so that we can get a feel for the prognosis prior to treatment, as well as to help us design a protocol to most effectively use the ovarian function that we have. When dealing with good oocyte quality, pregnancy rates can be quite high (50-70%), but these can drop significantly as ovarian function wanes. It is important to understand that many women that need a gestational carrier will have less than ideal ovarian function due to the condition that led her needs the GC in the first place. Thus, assessing ovarian function is done early on to provide the couple this important, highly individualized information.

Although the role of the oocyte is extremely important, the sperm and the uterus do not get a free pass in this process. A semen analysis is done to provide information on how the oocyte is to be inseminated. Although ICSI (provide a link to our explanation of this) is very helpful when the sperm is suboptimal, very poor quality sperm will lower the chances of success.

The process of implantation is extremely complex, but it appears that the endometrium (lining of the uterus) tends to be “permissive”; that is, it will usually work if we provide a normal embryo for it. Nonetheless, it is possible that an endometrium may not work which is why extensive evaluation of the gestational carrier is done to make sure that, to the best of our ability, the uterus is in good shape and will accept and nourish a pregnancy.

What are the risks of the Gestational Surrogacy treatment?
The risks may be broken down into several major areas (a) those related to providing the egg (b) those related to the laboratory component (c) those related to preparing the lining of the uterus, and (d) pregnancy related. As you will see, most are very infrequent occurrences, but are things that individuals considering this process should be aware of.

  1. Risks related to providing the egg (for the intended parent or oocyte donor undergoing the IVF stimulation to produce the eggs)
    1. Small (1-2%) risk of overstimulation (hyperstimulation syndrome) which can result in fluid shifts that cause electrolyte imbalances and increased risk of clotting. Is almost always treated as an outpatient.
    2. Risk of failing to respond to medications and not providing eggs. This is related to the ovarian function and is what ovarian reserve testing tries to address
    3. Risk of failing to provide good quality eggs. Again, this is related to the ovarian function and is what ovarian reserve testing tries to address
  2. Risks related to the laboratory component (for the intended parents)
    1. Failure to produces mature eggs
    2. Failure of fertilization
    3. Failure of the embryos to survive to a point where they could be transferred.
    4. All of these are primarily related to the quality of the eggs and sperm.
  3. Risks related to the preparation of the lining of the uterus (for the gestational carrier)
    1. Failure of the lining to respond to the hormonal regimen. The likelihood of this can be reduced by testing the gestational carrier with a test cycle to make sure the endometrium does respond.
    2. The development of polyps or fibroids during treatment
  4. Risks related to pregnancy (refs 4-10) (for the gestational carrier)
    1. Failure to achieve pregnancy- usually embryo related.
    2. Miscarriage- occurs at the rate that is consistent with the ovarian function of the egg provider, which can be as low as 10%, but as high as 40-50%
    3. Ectopic pregnancy (pregnancy outside uterus). Even though the embryos are transferred into the uterus, they can float into the fallopian tubes. This risk is lower in assisted reproduction (~ 1%) than it is in natural conception (~ 5%) and there are effective medical and surgical treatments. Nonetheless, maternal mortality for ectopic pregnancy is 38/100,000 live births.
    4. Losses after the first trimester (~ 1-2%)- this is the typical loss rate in healthy women
    5. Multiple gestation- although twin pregnancies do well in the US, they are 4-5 times more risky than a singleton pregnancy. This is why in most gestational surrogacy treatments we recommend single embryo transfer. This reduces the risk of twins from about 35% (with a 2 embryo transfer) to about 2-4% (risk of identical twinning). However, this also reduces the chances of a successful pregnancy by about a third due to the limitations of our ability to select the embryos. Pre-implantation Genetic Diagnosis (PGD) can be applied to offset this to a large degree, but this also adds cost and may not be suitable in all situations.
    6. Pregnancy complications (for singleton pregnancies): pre-term labor (15%), pre-term delivery (10%), gestational diabetes (3%), pre-ecclampsia (6%), fetal growth restriction (15%), cerebral palsy (0.2-0.7%), fetal death (0.4%), maternal death (0.2%)

This list is not an all-inclusive and is not a substitute for reading your consents / contracts or appropriate counseling with your physician or attorney.


  1. The Book of Genesis (The Book of Genesis 16:1-15; 17: 15-19). The Bible
  2. Recommendations for practices utilizing gestational carriers: an ASRM Practice Committee guideline. Fertil Steril 97:13-1-8, 2012
  3. Brisdon PR. Surrogacy. In: A text book of in vitro fertilization and assisted reproduction. Second Edition. Parthenoon Publishing Group. P 361-8. 1999
  4. ACOG  Educational Bulletin 253, Nov 1998
  5. Henderson CE et al J Natl Med Assoc, 1995;87:757-8
  6. Wein P et al Aust NZ J Obstet Gynaecol 1992;32:325-7
  7. Adams DM et al AJOG1998;178:843-847
  8. Martin JA et al Vital Health Stat 1997;21:1-20
  9. ACOG Practice Bulletin 56, October, 2004
  10. Neonatal Encephalopathy and Cerebral Palsy, ACOG and AAP, 2003