In vitro fertilization (IVF)

Abington Reproductive Medicine
Price Medical Building
1245 Highland Avenue, Suite 404 •  Abington, Pennsylvania 19001
215-887-2010  • 215-887-3291 fax

In order to understand how IVF works, it is important to understand how fertilization occurs under normal situations.

Each month at mid-cycle, an oocyte (egg) is ovulated into the fallopian tube. After intercourse, millions of sperm are deposited into the vagina, with only a few dozen swimming through the uterus and into the fallopian tube. When one sperm penetrates the egg, fertilization occurs. The resulting embryo travels down the fallopian tube for four or five days, multiplying into many cells. The embryo then enters the uterus, where it implants and grows over the next nine months.

With IVF, the fallopian tubes are bypassed. The egg is removed from the ovary immediately prior to ovulation and placed in a petri dish with sperm from the husband and/or donor. After several days, embryos are transferred into the woman’s uterus for implantation and pregnancy.

Who qualifies for IVF?
When IVF was first attempted, its application was limited to women with absent or severely damaged fallopian tubes. Since then, applications for IVF have greatly expanded to include couples with male infertility (e.g. low sperm count, immunological infertility), patients with severe endometriosis, unexplained infertility and those with a variety of other fertility-related conditions.

There are four central steps in the IVF process: induction and timing of ovulation, oocyte retrieval, fertilization and embryo transfer. A description of each follows.

Induction and timing of ovulation
One of the most important steps in IVF involves obtaining eggs immediately prior to ovulation. Patients are prescribed ovulation-inducing medications (e.g. Repronex, Gonal F, Follistim, etc.) to promote the simultaneous maturation of eggs.

Patients typically begin taking ovulation-inducing medications within the first six days of their cycle, depending on the length of their natural cycle. Three or four days later, blood tests for estrogen and a transvaginal ultrasound are usually initiated and repeated as needed to follow follicle growth and development.

Injectable ovulation-inducing medications are usually given at home by the patient or her partner. Patients and their partners will be taught how to administer the injections with the dosage based on the results of that day’s blood test results. The results are usually available from 1 to 4 p.m., and medications are generally taken from 6 to 11 p.m. On weekends, patients are called between 11 a.m. and 2 p.m. When the follicle grows to a certain size and blood estrogen levels reach a necessary value, the hormone hCG is injected subcutaneously in the evening to prepare for egg retrieval, which occurs approximately 36 hours later.

Note: A recent study has raised the possibility of a link between ovulation-inducing agents and an increased risk of ovarian carcinoma. Similar studies have not demonstrated this association.

Collecting eggs from the ovaries
The next step in IVF involves collecting the eggs from the ovaries. The eggs are contained within small fluid collections in the ovaries called follicle cysts. Successful egg retrieval occurs in 95 percent of all cases. With IVF, egg retrieval is performed via a transvaginal ultrasound. Patients undergoing this procedure are first given intravenous sedation. Next, the ultrasound probe is placed into the patient’s vagina and a needle is inserted through the vagina and into the ovary. Each follicle is then aspirated to retrieve the eggs. Typically, one oocyte is collected per follicle.

Fertilization in vitro
While techniques and subtle details vary from center to center, at Abington Reproductive Medicine, the first step of fertilization in vitro involves asking the male to produce a semen specimen by masturbation the day before or shortly after the scheduled egg retrieval. Occasionally he will be asked to produce on both days. To separate the semen (the liquid portion of the ejaculate that surrounds the sperm), a small amount of semen is mixed with a sterile culture medium in a test tube. The mixture is spun in a centrifuge, and the washed sperm form a pellet in the bottom of the test tube. The sperm wash is repeated several times. Some of the sperm are then placed together with the eggs and allowed to incubate together for approximately 18 hours. The following day, the egg is observed under a microscope to determine if fertilization has occurred.

If a fertilized egg is detected, it is then transferred into a second culture medium and incubated for an additional 22 to 46 hours. At this point, the embryo is ready to be transferred to the uterus.

In certain situations, fertilization may fail to occur. These situations include severely low sperm counts, poor sperm quality or defects in the egg membrane. Newer techniques of micromanipulation may correct these problems.

Embryo transfer
Perhaps the most simple, straightforward aspect of IVF is embryo transfer (ET), a procedure by which the embryo is placed into the uterus. No anesthesia is necessary, and the procedure is not painful.

During ET, a speculum is placed in the vagina and the cervix is cleansed with sterile solution. A special thin Teflon (Wallace) catheter has been designed for this procedure. The embryos are loaded into the catheter tip, which is then threaded through the cervix near the top of the uterus where the embryo(s) are released. The catheter is held in place for ten seconds and slowly removed.

Often, an abdominal ultrasound is used to guide the catheter. Dr. Barmat has developed the "Barmat ultraview catheter." This enables better visualization of the ET catheter tip to ensure optimal placement of the embryos to achieve highest success rates.

The patient will be asked to remain in the same position while the catheter is examined under the microscope to be sure that the embryo(s) do not remain inside the catheter. If this is the case, the process will be repeated. After rechecking the catheter, the speculum is removed, and the patient is instructed to lie flat for approximately ten minutes.

She will then be discharged from the Toll Center and asked to remain in bed as much as possible for the next 24 hours with minimal activity for the following 48 hours. While treatments may vary, progesterone is usually given as a daily, intramuscular injection or vaginal gel beginning the day after retrieval and continuing until the pregnancy test is either positive or negative. Occasionally, mild cramping, spotting and breast tenderness follow the embryo transfer. These symptoms do not necessarily indicate a problem.

Only embryos that divide (cleave) can be transferred into the patient’s uterus. If additional embryos are produced, they may be frozen and stored. The transfer of multiple embryos can result in the growth of more than one fetus, and twin pregnancies occur in approximately 35 percent of all IVF pregnancies. There have been reports of IVF pregnancies involving four, five and six fetuses.

Freezing of embryos (embryo cryopreservation)
Earlier reference was made to the freezing of excess embryos, which involves freezing embryos under carefully controlled conditions, storing the embryos under liquid nitrogen for various time intervals and thawing them for placement in the recipient’s uterus. Human pregnancies have been established following transfer of embryos cryopreserved at all stages, from pre-cleavage to expanded blastocyst.

The risks to the embryo(s) include, but are not limited to, the potential of a laboratory accident occurring during the additional handling and manipulation required and a failure of refrigeration equipment. These risks can be minimized, but not eliminated, by employing trained personnel and scrupulously adhering to quality-control procedures. It must also be understood that substantial loss of embryo viability can occur even during an uneventful cryopreservation procedure and a significant number of thawed embryos may be rendered untransferable.

Success rates and IVF outcomes
Since 1978, thousands of living births have occurred via IVF. Recently, Abington Reproductive Medicine celebrated our 2,000 live IVF birth!

In order to put these success rates in perspective, one must recognize that the human reproductive system is very inefficient. Of 100 eggs exposed to potential fertilization among fertile couples, it is estimated that only 25 will actually produce a viable offspring. The other 75 percent will be lost, usually prior to the first missed period. Therefore, if we do as well as nature, we can only anticipate a 25 percent success rate. To improve outcomes, we may place multiple embryos back into the uterus. Any remaining normal embryos can be frozen for later transfer.

Congenital anomalies, birth defects, genetic abnormalities, mental retardation and/or other possible conditions may occur in children born through IVF, just as they may occur in children born through natural fertilization. There are absolutely no assurances that these defects will not occur. There does,however, not appear to be any correlation between these conditions and IVF.

As with pregnancies resulting from natural fertilization, an IVF pregnancy may result in a miscarriage, tubal (ectopic) pregnancy or stillbirth. Tubal pregnancies have been reported in approximately five percent of all IVF pregnancies. Should this major complication occur, an operative procedure or medical management will be necessary.

Click here for more information about the safety of IVF.

Why pregnancy may not occur
There are many reasons why pregnancy may not occur following IVF and embryo transfer. These explanations include, but are not limited to:
• The timing of ovulation may be misjudged, or ovulation may not be able to be predicted or may not occur
• Attempts to obtain eggs that develop during the monitored cycle may be unsuccessful
• The eggs obtained may be abnormal or may have been damaged during the retrieval process
• A semen specimen may not be able to be provided
• Fertilization of eggs to form embryos may not occur
• Cleavage or cell division of the fertilized eggs may not take place
• The embryo may not develop normally
• Implantation may not occur
• Equipment failure, infection and/or human error or other unforeseen and uncontrollable factors, which may result in the loss of or damage to the eggs, the semen sample and/or the embryos

Variations of IVF
Some patients may require one of the following variations to their IVF procedure:
ZIFT
GIFT
Hysteroscopy

Team approach
IVF is a complicated procedure involving physicians, scientists, laboratory technologists, nurses and many others. You can rest assured that each team member of Abington Reproductive Medicine is highly trained and qualified to help you through your procedure, answer questions and coordinate your cycle.

Emotional aspects of IVF
While IVF can offer new hope to those who may otherwise be unable to conceive, it also has the potential to create added stress, due to the fact that participants must be monitored so closely and so much emphasis is placed on precise timing. Participants must also face the possibility that their attempts may fail or be cancelled. While most participants are able to cope with the various stresses associated with this procedure, all participants should be aware of the various counseling and support outlets available to them.

For more information about the emotional aspects of IVF, please visit the “Counseling and Support” section of this Web site, or contact our office at 215-887-2010.