How successful is in vitro fertilization?

The chances of successful pregnancy with in vitro fertilization is directly related to the age of the woman who provides the egg. Most in vitro fertilization programs divide up their success rates according to age. For example, clinics will report pregnancy rates for women under and over the age of 35 years. There is certainly a deterioration in the quality of eggs from the mid-thirties onwards. Some clinics divide up success rates further, and specifically report pregnancy rates for women between the ages of 35 and 37, 38 and 39, 39 to 42, and then over the age of 42. Our clinic is still young, however, our clinical pregnancy rates in year 2003 for women under the age of 35 was 67%, with a fall-off in pregnancy rates for women between the ages of 36 and 44 years.

Success rates are further influenced by the number and quality of eggs that are retrieved from the ovary, by the quality of the uterus, including the endometrial lining and the presence or absence of uterine fibroids, by the number of embryos that are transferred and also by maternal weight. Elegant studies have shown very carefully that obesity will significantly affect the chances of pregnancy as well as the risk of miscarriage.

Obviously, there are patients in all categories who may have poorer chances of pregnancy success than others of equivalent age. Such patients would include those with a history of previous in vitro fertilization failures, as well as those with limited ovarian reserve and other pelvic factors such as uterine fibroids and tubal disease or endometriosis. This is why it is so difficult to draw conclusions from statistics provided by various clinics. There are indeed some clinics who will not take on women who are obviously at low risk for for successful pregnancy – for fear that a lack of success could adversely skew statistics.

What are my risks related to in vitro fertilization?

The risks may be divided into various categories:

1. The risks related to ovulation induction (the use of fertility drugs).
2. The risks related to the surgical retrieval of eggs.
3. The subsequent risk of pregnancy – specifically of multiple pregnancy.

One of the commonest serious side effects from using fertility drugs is a condition known as ovarian hyperstimulation syndrome (OHSS). Ovarian hyperstimulation syndrome becomes a risk in women who develop more than 20 follicles in response to the fertility drugs. In these circumstances the blood estrogen levels are often very high, and this combination causes OHSS. It is not a very well understood condition, however, this combination of events tends to lead to a metabolic imbalance which increases the risk of thrombosis, as well as having an effect on body tissue permeability, which results in collection of fluids in the abdomen and chest. The best form of management is prevention. Women at particularly increased risk for this condition are women with a condition known as polycystic ovarian syndrome, or younger women with a history of infrequent or longer than average menstrual cycles.

Common symptoms of early OHSS include abdominal discomfort, bloating and nausea. More severe symptoms would include a decrease in urine output and difficulty breathing. Ways to avoid this syndrome are to reduce the medication dosage in patients at risk, and to follow the development of the follicles very carefully. If too many follicles are developing, a process called “coasting” may be done, during which time no further fertility drugs are given and the estrogen levels are monitored until they start declining. Only then would an egg retrieval be performed – thereby reducing the risk of OHSS. Most cases of OHSS are mild, though specific management may include surgically draining the fluid from the abdomen (by using a fine needle), careful fluid balance and the use of blood-thinners.

During egg retrieval, a needle is passed under ultrasound guidance through the vagina into the ovaries. The follicles are then aspirated, the fluid collected and the eggs isolated. We use a combination of local anesthetic and intravenous sedation during the procedure. Like any surgical procedure there are risks of bleeding, infection, and injury to structures around the ovary. Such structures include bowel, the ureters and bladder. Prophylactic antibiotics are always used, and the risk of infection, bleeding and organ injury is, in fact, very low.

The main pregnancy risks related specifically to in vitro fertilization are those associated with multiple pregnancies. Our motto is “As Many Babies As You Want, Though Preferably One At A Time”. However, we have a responsibility to maximize chances of pregnancy, keeping in mind a desire to keep the risk of multiple pregnancy to a minimum. As a rule of thumb, we at Victoria Fertility Centre will not transfer more than two embryos in a woman under the age of 35. The number of embryos transferred in women over the age of 35 is largely dependent on their prior IVF history and the quality of the embryos themselves. Just about every pregnancy complication imaginable is increased when there is a multiple pregnancy. The most specific baby-oriented risk of multiple pregnancy is premature delivery. Although twins are somewhat acceptable they are not desired. In higher order multiple pregnancies than twins, a preferred option would be a process called selective reduction, which is done at around 12 weeks’ gestation. This involves sacrificing one of the fetuses to give the others a better chance at reaching maturity.

How painful is the egg retrieval process?

This is an invasive process and certainly involves some discomfort. Prior to egg retrieval, I routinely give our VFC patients a session of acupuncture, both to provide relaxation and also some form of pain relief. After this acupuncture session an intravenous line is established. In the operating room, a combination of a sedative and narcotic is then administered intravenously. After the vagina has been cleaned, local anesthetic is injected into the vaginal fornices before doing the retrieval. The retrieval is then done under ultrasound guidance, and extra narcotic and sedation given as necessary. Most patients find that the procedure is not nearly as uncomfortable as they imagined. If one has to consider the discomforts caused by pregnancy itself, not to mention the labour and delivery process, egg retrieval is normally minor in comparison.

What side effects can I expect on the IVF medications?

The fertility drugs used do not seem to cause direct side effects, and the side effects are therefore related to the actual effects that these drugs have on the ovaries. As the ovaries begin to swell, there can be some pelvic and abdominal bloating. Some women do experience minor mood changes, headaches and nausea – although all of these are uncommon.

Is there an increased risk of birth defects and chromosome abnormalities in babies born after in vitro fertilization and ICSI?

As a result of strict regulatory bodies, all babies born after in vitro fertilization and ICSI are closely monitored. So far, the worldwide results are very reassuring – although it is appreciated that this is a young science. There do not appear to be any increased risk of birth defects or genetic abnormalities in babies born after standard in vitro fertilization. The process of ICSI is a micromanipulation technique whereby a single sperm is injected into an egg. Because this overrides nature, there is a chance that genetic material from a man who would otherwise be incapable of impregnating a woman may be transferred to the offspring. It should be remembered that in all naturally conceived children there is an approximately 4-6% of some form of congenital abnormality occurring independent of maternal age. These abnormalities would include things like clubfeet, cleft lip, hernias, extra digits, etc., etc. It is possible that with ICSI there may be a slightly increased risk of congenital birth defects – although there seem to be conflicting reports. For the most part the data is very reassuring, and IVF/ICSI is felt to be a safe science.

Is there an increased risk of cancer following infertility treatments?

There has been some concern raised over the past ten years that the use of fertility drugs and assisted reproductive technologies may put women at increased risk for either ovarian or breast cancer. Adding fuel to this concern was an irresponsible article published in the otherwise usually reputable Oprah Magazine. There has been an official response to this article from our North American fertility association – The American Society of Reproductive Medicine. I have included this response in a downloaded PDF file which is available on this website. In summary, there is no conclusive evidence that there is an increased risk of either breast or ovarian cancer related to either fertility drugs or in vitro fertilization. When digesting all of this information, one has to remember that first of all breast cancer is extremely common. Approximately 12% of all women will develop breast cancer in their lifetime. There are so many different variables that it is sometimes difficult to ascertain which may or not may be a responsible cause. When it comes to ovarian cancer, although the incidence is much lower (lifetime risk 1/60) there is also some confusion. Certainly, the most significant risk factors for ovarian cancer are either family history or childlessness. In other words, women who never have a pregnancy have an increased risk of ovarian cancer. It is therefore difficult to establish whether or not the link with infertility is related to not having children or the use of fertility medications, which may have been used previously in an attempt to assist conception.

These concerns continue to be monitored by our regulatory bodies, and information will be passed on to all our patients as it becomes available. At this time the reputable Cochrane Reviews do not find a link between either breast or ovarian cancer and in vitro fertilization. However, it remains our responsibility to use the most effective and efficient means to assist patients in overcoming subfertility.

Does endometriosis affect fertility and can it affect the success rates with in vitro fertilization?

Endometriosis is a condition in which the endometrial cells which normally line the inside of the uterine cavity (womb) grow outside the uterus. Endometriosis usually results in deposits (growths) of endometrial cells, which occur in clusters, typically on the ovaries, fallopian tubes, bladder, pelvic side walls and bowel. Endometriosis can also cause ovarian cysts (called chocolate cysts). Less commonly, endometriosis can occur in other parts of the body such as the lungs, liver and kidneys.

It is a confusing disease which may affect one in ten women during their childbearing years. It is especially common, however, in women having difficulty conceiving, and also in women experiencing pelvic pain. The typical symptoms of endometriosis include painful periods, premenstrual spotting, painful intercourse and difficulty conceiving. Endometriosis should be suspected in any woman with such symptoms. Although a clinical examination and pelvic ultrasound may be completely normal, some clues would include clinical tenderness between the uterus and the rectum felt during an examination, or ovarian cysts identified by ultrasound. The condition can be confirmed by doing a surgical procedure called a laparoscopy. Laparoscopy involves a general anesthetic and passing a small telescope through the belly-button (umbilicus) into the pelvic cavity to allow direct visualization. For the most part patients with endometriosis who require in vitro fertilization have about the same chances for a successful pregnancy as patients of the same age without endometriosis. However, there is some recent research which has identified an intrauterine chemical factor which may be associated with endometriosis and decreased chances of pregnancy. For this reason, depending on your personal history, we at VFC may suggest a different type of IVF protocol to maximize your chances of conception during in vitro fertilization.

Furthermore, there may be a link between endometriosis and altered immunity. The immune system in women is far more sophisticated than in men. In women, the immune system needs to adjust to prevent rejection of the foetus, which contains genetic material from the father. At the same time, it needs to continue to do its job in protecting women from infections and other hostile factors in our environment. It is for this reason that women are more prone to immune-related disorders than men. Some of these include conditions like rheumatoid arthritis, lupus and thyroid disease.

It has been long suspected that women with endometriosis may have a mild immune imbalance, making them more vulnerable to this specific disorder. If that is the case, it is also possible that such patients may be more likely to have an IVF failure or miscarriage. This is currently being researched.

Is miscarriage more common after in vitro fertilization than natural conception?

There does not seem to be a significant difference in the miscarriage rates conceived naturally or through in vitro fertilization. The single most significant factor related to miscarriage is maternal age. The risk increases with advancing age. For a woman in the early twenties the miscarriage risk is approximately 12%, however, for a woman in her early forties the miscarriage rate is between 25 and 50%. Another factor which affects significantly the risk of spontaneous miscarriage is weight. For example, for women under the age of 35 and of normal weight, the risk of miscarriage is approximately 15%. For this same group of women who are in an obese category (with a body mass index over 30) the risk of miscarriage is 35%.

What is the success rate with frozen/thawed embryos?

As with in vitro fertilization involving fresh embryos, the age of the egg provider is the single most important predictor of outcome. For embryos frozen on Day 3, approximately 70% will survive the freeze/thaw process. This may be higher for embryos frozen on Day 5 (blastocysts). The implantation rate for a successfully thawed Day 3 embryo would then be dependent on the maternal age of the egg donor. For women under 35, if two successfully thawed Day 3 embryos are transferred, the chances of pregnancy would be between 30 and 40%. These are therefore slightly lower pregnancy rates than would be seen with a fresh cycle. The success rates will decline as age advances.

What treatment options are available for women over the age 40?

When the egg provider is over the age of 40 years, the chance of success using her own eggs decreases significantly as we approach the age of 43/44. Between the ages of 40 and 42, the chances for successful pregnancy per cycle is around 30% if three embryos are available for transfer. By the age of 43 to 44, the chance of pregnancy falls to about 12-15%. There is also a significantly increased risk of miscarriage, approaching 50% by the time someone is 43 years old.

In vitro fertilization with egg donation is an option for all patients when egg production or embryo quality appears to be a major factor. This is especially relevant for patients over the age of 40 with decreased ovarian reserve.

What is IVF using a donor egg?

For women without ovaries or for women with poor ovarian reserve (usually related to age) an option for successful pregnancy would be in vitro fertilization with donor egg. Preferably, such an egg donor should be under the age of 35. During this process, the egg donor undergoes a cycle of in vitro fertilization. Her ovaries are stimulated in the usual fashion as described elsewhere in this website, and then the eggs are retrieved by transvaginal ultrasound. At the same time that this donor is going through an IVF cycle, the recipient is undergoing a different process. This process involves hormonal treatments to prepare the uterus to receive the embryo.

After the eggs are retrieved from the donor, they are fertilized using the recipient’s partner’s sperm (or donor sperm, depending on the circumstances). The donor’s role is then over.

The embryos are then cultured, and then either on Day 3 or Day 5, transferred into the uterus of the recipient.

Canadian Law does not allow the purchase of eggs. For this reason, in Canada, the egg donor is expected to go through the process with purely altruistic intentions. She is allowed, however, to be legally reimbursed for expenses incurred during the process. There can be no financial coercion during the process.

At VFC, we find that most of our egg donors are either relatives or personal friends.

What effect to fibroids have on fertility and the chances of success with in vitro fertilization?

Fibroids are the commonest tumour found in the human body. They are round muscle growths which occur in the wall of the uterus. They are almost always non-cancerous and harmless. They start as small pea-sized lumps but grow steadily during the reproductive years. They may or may not cause symptoms. Some of the common symptoms include heavy, painful periods and pressure on the bladder and rectum. They can also uncommonly cause pain if they undergo rapid change.

Fibroids that grow into the cavity of the uterus (submucous fibroids) can definitely interfere with fertility. Such fibroids should be removed prior to embarking on in vitro fertilization. Fibroids that grow within the wall of the uterus but do not displace or impact on the cavity of the uterus (the endometrial cavity) can potentially also interfere with the chances of conception. This is a very controversial area. Generally speaking, if fibroids are less than 5 centimetres in size and not impacting on the cavity we do not recommend that they be surgically removed. We always have to remember that a surgical procedure carries risk. The surgical removal of fibroids is called a myomectomy. During a myomectomy there is a risk of damage to the uterus – and as such the pros and cons of doing it should be carefully evaluated.

On the other hand, as mentioned above, if fibroids are growing into the cavity of the uterus they do need to be surgically removed. Most of these can be tackled by doing a hysteroscopy. This involves passing a fine telescope through the vagina and cervix, resecting the fibroids and thereby restoring the uterine cavity to normal.

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Does stress affect the chances of success with in vitro fertilization?

The frustration and sadness caused by infertility is up there with cancer, loss of a loved one and major illness. Although fertility treatments (including IVF) can be exciting and restore optimism, they are extremely stressful. We encourage all of our patients to meet with our reproductive psychologist to help deal with the stress along the fertility journey. We have a holistic approach to our medical care, and encourage our patients to learn coping strategies, and to adopt lifestyle changes which are helpful to their health in general. Specifically, we encourage exercise activities such as yoga and complementary medical therapies like acupuncture/acupressure.

What is ovarian reserve?

Unlike men who continue to manufacture sperm until they die, women are born with a finite number of eggs. At birth, the ovaries contain about 6 million eggs. By the time of puberty there are approximately 300,000 eggs remaining in the ovaries for future ovulation. Although many eggs are recruited each month during a natural cycle, usually only one egg matures. However, it is a wasteful process, and many eggs are dying naturally every day.

In addition to the reduction in egg numbers as years advance, there is also a decrease in egg quality. This is why the chances of conception decline with advancing years. It is also the reason why there is an increased risk for genetic abnormalities with advancing age.

There are two main ways of estimating ovarian reserve. The first is to measure the level of follicle stimulating hormone (FSH) and estradiol on the third day of the menstrual cycle. The second is to assess the volume and antral follicle count by ultrasound. The combination of these two tests will give us an idea of the ovarian reserve and the chances for being able to recruit enough eggs to complete an in vitro fertilization cycle.

How do I contact the Victoria Fertility Centre?

You can contact our clinic through the contact e-mail address given on the website. If you live locally, the preferred consultation should be done in person. Appointments can be made through our front desk.

If you live out of town and would like to consider a treatment cycle at Victoria Fertility Centre, Dr. Hudson would be happy to do a telephone consultation at a pre-arranged time. Please contact us with your details, and we can set this up.