In Vitro Fertilization: IVF

In Vitro Fertilization is commonly referred to as IVF. IVF is the process of fertilization by manually combining an egg and sperm in a laboratory dish. When the IVF procedure is successful, the process is combined with a procedure known as embryo transfer, which is used to physically place the embryo in your uterus.
What is involved with in vitro fertilization?

There are basically five steps in the IVF and embryo transfer process which include the following:

1. Monitor and stimulate the development of healthy egg(s) in the ovaries
2. Collect the eggs
3. Secure the sperm
4. Combine the eggs and sperm together in the laboratory and provide the appropriate environment for fertilization and early embryo growth
5. Transfer embryos into the uterus

Step 1: Fertility medications are prescribed to control the timing of your egg ripening and to increase the chance of collecting multiple eggs during one of your cycles. This is often referred to as ovulation induction. Multiple eggs are desired because some eggs will not develop or fertilize after retrieval. Egg development is monitored using ultrasound to examine the ovaries and urine or blood test samples are used to check hormone levels.

Step 2: Your eggs are retrieved through a minor surgical procedure which uses ultrasound imaging to guide a hollow needle through the pelvic cavity. Sedation and local anesthesia are provided to remove any discomfort that you might experience. The eggs are removed from ovaries using the hollow needle, which is called follicular aspiration. Some women may experience cramping on the day of retrieval, which usually subsides the following day; however a feeling of fullness or pressure may last for several weeks following the procedure.

Step 3: Sperm, usually obtained by ejaculation is prepared for combining with the eggs.

Step 4: In a process called insemination, the sperm and eggs are placed in incubators located in the laboratory which enables fertilization to occur. In some cases where fertilization is suspected to be low, intracytoplasmic sperm injection (ICSI) may be used. Through this procedure a single sperm is injected directly into the egg in an attempt to achieve fertilization. The eggs are monitored to confirm that fertilization and cell division is taking place. Once this occurs the fertilized eggs are considered embryos.

Step 5: The embryos are usually transferred into your uterus anywhere between one to six days, but most commonly it occurs between two to three days following egg retrieval. At this point, the fertilized egg has divided to become a 2-to-4 cell embryo. The transfer process involves a speculum which is inserted into the vagina to expose the cervix. A predetermined number of embryos are suspended in fluid and gently placed through a catheter into the womb. This process is often guided by ultrasound. The procedure is usually painless, but some women experience mild cramping.

These steps are followed by rest and watching for early pregnancy symptoms. A blood test and potentially an ultrasound will be used to determine if implantation and pregnancy has occurred.

Are there variations of in vitro fertilization?
Gamete intrafallopian transfer (GIFT) and zygote intrafallopian transfer (ZIFT) are two procedures related to IVF.
GIFT is similar to IVF, but the gametes (egg and sperm) are transferred to your fallopian tubes rather than your uterus and fertilization takes place in the tubes rather than in the laboratory. GIFT also involves a laparoscopic surgical procedure to transfer the sperm and egg into the tubes. GIFT accounts for approximately 2% of ART procedures in the United States.
ZIFT differs from GIFT in that the fertilization process still takes place in the laboratory versus the fallopian tubes. It is similar to GIFT in that the fertilized egg is transferred into fallopian tubes and it involves a laparoscopic surgical procedure as well. ZIFT accounts for less than 1.5% of ART procedures in the United States.

How successful is in vitro fertilization?
The success rate of IVF clinics depends on a number of factors including patient characteristics and treatment approaches. It is also important to realize that pregnancy rates do not equate to live birth rates. In the United States, the live birth rate for each IVF cycle started is approximately:

• 30 to 35% for women under age 35
• 25% for women ages 35 to 37
• 15 to 20% for women ages 38 to 40
• 6 to 10% for women ages over 40

The success rates of individual clinics are published on the web site of the Centers for Disease Control and Prevention.
When comparing success rates of different clinics, it is important to know what type of pregnancy is being compared. A biochemical pregnancy is one confirmed by blood or urine tests, but a miscarriage may occur before confirmation through an ultrasound. A clinical pregnancy is one witnessed through ultrasound. A miscarriage may still occur, but it is a significant difference.

What if I don’t produce healthy eggs or my husband is sterile?
IVF may be done with a couple’s own eggs and sperm or with donor eggs, sperm, or embryos. Some couples choose to use donor eggs, sperm or embryos because of genetic concerns. Donor eggs are used in approximately 10% of all ART cycles.

What are the risks associated with in vitro fertilization?
As with most medical procedures there are some potential risks. The risks of in vitro fertilization depend upon each specific step of the procedure.
Ovary stimulation carries the risk of hyper stimulation, where the ovaries become swollen and painful. This condition is called Ovarian Hyper stimulation Syndrome, which is usually rare, mild and involves the following potential side affects: nausea, vomiting, lack of appetite or a feeling of being bloated. More severe symptoms which occur in 1% of cases, include the following side affects:

• Severe abdominal pain
• Severe nausea or vomiting
• Decreased urinary frequency
• Dark colored urine
• Shortness of breath
• 10 pound weight gain within 3 to 5 days

Egg retrieval and the use of laparoscopy carries the normal risks related to anesthesia. Additionally, there is a slight risk of bleeding, infection, and damage to the bowel, bladder, or a blood vessel. Less than one patient in 1,000 will require surgery to repair damage during the egg retrieval process.
The chance of a multiples pregnancy is increased in all assisted reproductive procedures. There are additional risks and concerns related to multiples during pregnancy such as increased risk of premature delivery.
Assisted reproductive technologies involve a significant physical, financial, and emotional commitment on the part of the couple. Psychological stress and emotional problems are common, and even more so if IVF is unsuccessful.

How many embryos should be created or transferred?
The number of embryos that should be created or transferred during any single IVF cycle is open to debate. It has been said in the medical literature that transferring no more than four embryos per IVF cycle will yield optimal results. Transferring more than four is believed to result in excess numbers of multiple pregnancies, which increases the possibility of other complications.
Transferring four embryos versus one or two increases the probability that pregnancy will occur, but it is important to realize that all four embryos could implant. Some people have concerns regarding what happens to leftover embryos, so this would be something that you would want to thoroughly discus with your physician.
Intracytoplasmic Sperm Injection: ICSI
Intracytoplasmic sperm injection (ICSI) involves the direct injection of sperm into eggs obtained from in vitro fertilization (IVF).

How is ICSI performed?
There are basically five simple steps to ICSI which include the following:

1. The mature egg is held with a specialized pipette
2. A very delicate, sharp and hollow needle is used to immobilize and pick up a single sperm
3. This needle is then carefully inserted through the shell of the egg and into the cytoplasm of the egg
4. The sperm is injected into the cytoplasm and the needle is carefully removed
5. The eggs are checked the following day for evidence of normal fertilization

Once the steps of ICSI are complete and fertilization is successful, the embryo transfer procedure is used to physically place the embryo in your uterus. Then it is a matter of watching for early pregnancy symptoms. Your fertility specialists may use a blood test or ultrasound to determine if implantation and pregnancy has occurred.

Are there specific situations where ICSI might be recommended?
ICSI may be recommended when there is any reason to suspect that achieving fertilization may be difficult. ICSI is most often used with couples who are trying to get pregnant and there are male infertility factors. Male factor infertility can include any of the following problems: low sperm counts, poor motility or movement of the sperm, poor sperm quality, or sperm that lack the ability to penetrate an egg.
Azoospermia is a condition where there is no sperm in the male’s ejaculation. There are two types of azoospermia, obstructive and non-obstructive. Obstructive azoospermia may be caused by any one of the following:

• Previous vasectomy
• Congenital absence of vas
• Scarring from prior infections

Non-obstructive azoospermia occurs when a deficient testicle is not producing sperm.

How is sperm retrieved for use in ICSI?
For men who have low sperm count and sperm with low mobility, the sperm may be collected through normal ejaculation. If you have had a vasectomy, the microsurgical vasectomy reversal is the most cost-effective first choice option for fulfilling your desire to have children.
Needle aspiration or microsurgical sperm retrieval are good alternatives for cases where a competent microsurgical vasectomy reversal has failed, or where the man is opposed to surgery. Needle aspiration allows physicians to easily and quickly obtain adequate numbers of sperm for the ICSI procedure. A tiny needle is used to extract sperm directly from the testis. Needle aspiration is a simple procedure performed under sedation with minimal discomfort; however there is potential pain and swelling afterwards. The sperm obtained from testis is only appropriate for ICSI procedures when testicular sperm is not able to penetrate an egg by itself.

What health concerns are there when considering ICSI?
There are recent indications that developing babies from pregnancies achieved through artificial insemination and particularly ICSI may face an increased risk for imprinting defects. Imprinting refers to the phenomenon by which particular genes function differently depending on whether they involve a particular chromosome passed on by the father or mother. Prader-Willi Syndrome is a sample imprinting defect passed on by the father and Angelman Syndrome is a sample imprinting defect passed on by the mother. Reproductive researchers are concerned that manipulation of either gametes or zygotes may affect the imprinting process or the subsequent release.
Additionally, in cases of severe male infertility problems, the genetic cause of the man's infertility may be passed on to the offspring.