Surrogacy

By Steven T. Dodge, M.D.
California North Bay Fertility Medical Associates
Santa Rosa, CA, USA

A very exciting and significant advance made in reproductive medicine in the past decade is the process of gestational surrogacy, a type of in vitro fertilization that allows one woman to give birth to the genetic offspring of another couple. This can give couples with previously poor or even hopeless fertility prognoses an excellent chance to become parents.

The most common reason for gestational surrogacy is uterine factor infertility. This ranges from absence of the uterus (congenital or as a result of surgery) to non-function of the uterus due to multiple fibroid tumors, scar tissue in the interior cavity or prenatal exposure to diethylstilbesterol (DES). Surrogacy is also necessary for some women who are unable to carry a pregnancy to full term due to miscarriages or premature delivery. Finally, there a few women for whom pregnancy would be dangerous due to underlying health problems such as high blood pressure, a heart condition and/or impaired kidney function.

Whatever the reason, the first step in arranging for gestational surrogacy is to find a suitable surrogate. Asking someone to carry your baby for you is obviously a very large request and selecting the right person is critical. Fortunately there are a reasonable number of women who enjoy being pregnant and who also embrace the opportunity to help someone have the baby of their dreams.

Surrogates

There are two basic sources of surrogates: someone you know (a very close friend or relative) or someone you find with the help of an agency. In either case the woman must be free to make her decision to carry the pregnancy without any coercion or pressure. She must also be healthy and not have a general medical or obstetrical condition that would make another pregnancy dangerous. In general it is best for the potential surrogate to be less than 40 years old.

Most surrogates from agencies are healthy young women less than 39 years old and come from all walks of life and ethnic backgrounds. They have all had at least one successful pregnancy and birth. While they receive a fee for their services they are all very motivated to help couples achieve their dream of having a healthy baby.

Potential surrogates must undergo medical and psychological screening tests which include a careful medical history, a pelvic examination (including a pelvic ultrasound), blood tests to look for infectious diseases (HIV, hepatitis B, hepatitis C, syphilis and HTLV-I), cervical cultures for gonorrhea and chlamydia and hormone blood tests. The psychological screening includes an interview with a therapist experienced in this area.

Treatment Process

It is best to think of the gestational surrogacy process as an in vitro fertilization (IVF) cycle split between two women, the genetic mother who provides the eggs and the surrogate who receives the fertilized eggs. Both women take birth control pills for a few weeks and then receive a medication called Lupron to synchronize their menstrual cycles and thereby get both of them to the "starting gate" at the same time. The surrogate then begins receiving estrogen in the form of an estradiol valerate injection twice a week. This estradiol is the same main estrogen normally produced by the ovaries.

Meanwhile the genetic mother receives daily injections of fertility drugs (such as Follistim, Fertinex, Repronex, Gonal-F, Humagon, HMG or Pergonal) which help mature a group of eggs in her ovaries. Usually 7-12 days of fertility drugs are required before the eggs are mature. Soon after this point the surrogate begins progesterone, the only other hormone necessary to maintain pregnancy. This is in the form of oral capsules, a daily injection and/or Crinone vaginal cream. Both women have their injections given at home by a spouse, relative, friend or neighbor (who we train appropriately) and thus frequent trips to our office are not needed.

The eggs are gathered at the "egg retrieval" which is a procedure done in our office under light anesthesia (actually intravenous sedation) administered by an anesthesiologist. A needle guided by ultrasound is used to pass through the top wall of the genetic mother's vagina and into the fluid filled egg sacs ("follicles") in her ovary. This may sound complex but is actually quite easy and causes no pain, thanks to the anesthesia. It takes about 15 minutes to gather the eggs and the vast majority of patients are ready to go home 60-90 minutes later. The fluid we remove from the follicles is given immediately to our embryologists who use their microscopes to find the otherwise invisible eggs.

The eggs are usually inseminated a few hours after retrieval with sperm from the genetic mother's husband ("genetic father"). This is done by our embryologists who are also responsible for culturing the fertilized eggs (now called embryos) until the time of transfer to the surrogate's uterus. The embryo transfer is usually done 3 days after the egg retrieval when the embryos are at the 4-10 cell stage. Occasionally the embryos are cultured to 120 hours (5 days) before transfer, at which point they are blastocysts.

The embryo transfer is a very simple procedure and is nearly always completely painless. It is very much like a routine pelvic exam and involves the passage of a very small plastic catheter through the surrogate's cervix. A tiny drop (20-30 microliters) of culture media with the microscopic embryos suspended within is deposited in the upper reaches of the uterus. Good quality embryos that are not transferred can be frozen for a later transfer (in a few months if the first transfer is not successful or several years later if it is).

Success Rates

The chance of pregnancy with gestational surrogacy depends on the age of the genetic mother and the ability of her ovaries to respond to the fertility medications. For women less than 35 the probability of success is quite high: 60-75% per cycle. When the genetic mother is between 35 and 40 we have noted an approximate 50% chance of successful pregnancy per try. For the 41-43 age range the success rate is lower: 25-35% per cycle. Most pregnancies are singletons (one baby) but twins are not rare and occur in about 25% of gestational surrogacy pregnancies. Triplets or larger multiples have become very rare, i.e. an incidence of less than 5%.

Risks to Genetic Mothers

The processes of IVF alone and IVF with gestational surrogacy have very good safety track records. Nonetheless we counsel all women who undergo IVF about 4 important actual or potential risks. These are: a 1 in 20,000 risk of serious (and possibly fatal) anesthesia complications, a 1 in 1,000 risk of infection after the egg retrieval, a 1 in 100 (1%) risk of enlarged and painful ovaries (ovarian hyperstimulation) and potential long term health hazards of the fertility drugs. The latter risk is a theoretical one as thus far no increased risks of any type of cancer (including breast, ovary and uterine) have been reported.

Risks to Surrogates

For surrogates the main significant risk of the process is that of pregnancy itself or one of its complications (such as miscarriage or ectopic pregnancy). As these women have all had successful pregnancies before the risks of medical or obstetrical complications are very low, but not zero.

A special risk of gestational surrogacy is that of too much success (multiple pregnancy). This is especially true when the genetic mother is less than 35 years old. Before the power of this process was understood large multiple pregnancies (triplets and quadruplets) were not rare. Now only a small number of the healthiest embryos are transferred. The high success rate has been maintained and the really large multiples (quadruplets, quintuplets) have been eliminated. Triplets have been reduced to a very low level, leaving only twins as a continued problem.

Because the eggs come from another person there is also a theoretical risk to the surrogate of the transmission of disease, such as hepatitis or AIDS. Therefore both the genetic mother and father must be pre-screened for infectious diseases and thus far no case of disease transmission has been reported.

Legal Concerns

One of the main fears that couples have is that their surrogate might wish to keep the baby or demand maternal visitation rights. This happened several times in the 1980's when the only form of surrogacy was "biological surrogacy" where the surrogate was also the genetic mother because her egg had been fertilized to produce the pregnancy. We are aware of only one case where a gestational surrogate sought maternal visitation rights through legal action. This was here in California and the court's decision to deny the surrogate any parental rights was upheld in both the Court of Appeals and Supreme Court.

We therefore believe the risk of this problem is very low but to keep it at the lowest level possible it is our policy to only work with surrogates who come from a reputable agency or who are very closely connected (friend or relative) to our patients. The aforementioned legal case in California involved a couple who recruited a surrogate on their own, without the judgement and legal expertise of an experienced agency.