|
In Vitro Fertilization (IVF)
In-vitro fertilization is the fertilization of eggs by sperm outside the body. In IVF, eggs are removed from the woman’s ovaries and are fertilized with the man’s sperm in the laboratory to create embryos which can then be transferred to the woman’s uterus. IVF treatment is used when there is damage to the fallopian tubes, severe male factor infertility, severe endometriosis, or when other infertility treatments have failed or in older women with a long duration of infertility.
The hormone therapy that precedes the egg retrieval is more complex than hormone therapy given before IUI in basic treatment. With IVF, the goal of hormone therapy is twofold: to stimulate the ovaries to produce many mature eggs and, to prevent (a premature) ovulation before egg collection. There are different medications and strategies that can be used to achieve the two goals of ovarian stimulation and control of ovulation. The plan and choice of medications will be made based on the couple’s test results and unique history.
IVF Medication
The medications that are used prior to egg retrieval include the following:
Oral Contraceptives
The oral contraceptive pill is used to prevent the formation of ovarian cysts in treatment (cysts are not dangerous but interfere with treatment), and to schedule the timing of the treatment so that appointments can be planned in advance.
Oral contraceptives are prescribed for a short duration and are not usually associated with side effects.
Gonadotropins (FSH and LH)
Gonadotropins are hormones that signal the ovaries to produce eggs. These are prescribed to stimulate the ovaries to produce a number of mature eggs prior to egg retrieval.
Gonadotropins are taken by subcutaneous injection on a daily basis for about two weeks. Most women who take gonadotropins do not have serious side effects but those who do report temporary side effects that include inflammation at the injection site, mood swings, breast tenderness, abdominal bloating/ discomfort, and headache.
GnRH Agonist / GnRH Antagonist
GnRH Agonist or Antagonist is prescribed to prevent ovulation during treatment. Both Agonist and Antagonist act on the brain to suppress the secretion of hormone (the “LH surge”) that normally provokes ovulation.
GnRH Agonist and Antagonist are taken by subcutaneous (under the skin) injection on a daily basis. Side effects with GnRH Agonists are rare but some women may experience temporary menopausal-like side effects including hot flushes, headaches and mood changes. The use of Antagonist is not usually associated with side effects.
hCG
Human Chorionic Gonadotropin (hCG) is given to bring about the final maturation of eggs in preparation for fertilization.
hCG is given by subcutaneous injection 35 hours before the scheduled egg retrieval. Side effects after hCG injection are extremely rare and include inflammation of the injection site and “ovulation- like” cramping.
Additional hormone therapy is given after the egg retrieval, in order to help implantation of the embryo and to support the (hoped for) pregnancy. These include:
Estrogen
Estrogen helps develop and support the endometrium (lining of the uterus). Estrogen is taken as an oral medication on a daily basis through the first trimester of pregnancy. Side effects are rare but may include breast tenderness, mood changes, water retention, nausea, and fatigue.
Progesterone
Progesterone plays an important role in supporting the endometrium in pregnancy. Progesterone is taken on a daily basis by intramuscular injection or by vaginal suppository through the first trimester of pregnancy. Side effects are rare but include reactions at the site of injection, swelling, mood changes, PMS-like symptoms, and rarely allergic reactions.
Medrol
Medrol is a steroid that may help implantation. Medrol is taken by mouth and is begun prior to embryo transfer. Medrol is taken for a short duration and is this situation is rarely associated with side effects.
Doxycycline
Doxycycline is an antibiotic that is begun prior to embryo transfer, to help create a favourable environment for implantation. Doxycycline is taken orally.
Monitoring
Women following hormone therapy prior to egg retrieval are carefully monitored by vaginal ultrasound and serum Estradiol (hormone blood test). Ultrasounds are planned at the beginning of ovarian stimulation and then every 1-2 days once follicle growth is established. The dose of gonadotropins is adjusted according to the results of the ultrasound scan and blood test. Cycle cancellation may be considered if response to hormone therapy is poor or, if ultrasound reveals an over response to medications and a significant risk of Ovarian Hyper Stimulation Syndrome (OHSS).
Monitoring continues until at least three follicles reach maturity and the plan is made for egg retrieval. Final follicular maturation is triggered by an injection of HCG, given 35 hours prior to retrieval.
Oocyte Retrieval “Egg Collection”
Before the procedure, a fine needle is attached to side of the ultrasound probe normally used for vaginal scans. The probe is then placed in the vagina and when the ultrasound picture shows that the probe is lying next to the ovary, the needle is advanced into the ovary. The needle punctures each follicle on both ovaries and drains the fluid inside each follicle. The follicular fluid is examined under a microscope for the presence of an egg.
Egg retrieval usually takes about 20-30 minutes to complete, but may vary depending on the number of follicles. It is very important to us that you are comfortable during the egg retrieval and that your treatment remains a positive experience. We make a special effort to reduce any discomfort during the procedure by administering a local analgesic into the vagina and supplementing it with strong intravenous sedation and analgesics at regular intervals. If you prefer, the egg retrieval may be done under spinal or general anaesthesia.
The recovery period following egg retrieval lasts for 1-2 hours, until any anaesthetic medications given during the procedure are eliminated. Bleeding sometimes occurs following retrieval, but should not be heavy. Discomfort in the form of cramping or soreness may persist to the next day but can usually be well managed with Tylenol. Routine activities are normally possible the following day.
Fertilization of the Eggs
Collected eggs are placed in Petri dishes that contain culture medium that provides nutrients necessary for growth, and partner’s sperm is added (about 100,000 sperm sample are added to each egg). Dishes are placed in incubators overnight for fertilization.
Embryo Transfer
Embryo transfer takes place two to five days after the egg retrieval. The decision about when to transfer embryos is made on an individual basis and depends on the number and quality of embryos.
The decision about how many embryos will be transferred is also individual, and depends on the female’s age, prior pregnancies, previous treatment results, and the quality of the embryos. Each couple is counselled before treatment and again at the time of transfer, about the number of embryos that will minimize the risk of multiple pregnancy and maximize the chance of pregnancy.
At the time of embryo transfer, the embryos are loaded onto a very fine plastic catheter and inserted into the uterine cavity. This procedure takes about 15 minutes and does not usually cause any discomfort. After an embryo transfer, daily activities can be continued as usual.
Pregnancy Testing
The pregnancy test is performed at the Centre 2 weeks after the egg retrieval and transfer. An ultrasound scan is usually scheduled two weeks after a positive pregnancy test to confirm the on-going pregnancy.
Risks of Treatment
IVF treatment is generally considered safe however there are some risks that need to be considered.
The largest risk is that of multiple pregnancy. When two or more embryos are transferred in IVF treatment, there is a risk that both or all will implant. About 25% of IVF pregnancies are twin pregnancies and about 5% are triplet pregnancies. Multiple pregnancies present health risk to both the mother and unborn children (this applies to all multiple pregnancies and equally those that are naturally conceived). Maternal risks associated with multiple pregnancy include increased risk of Gestational Diabetes (diabetes in pregnancy), Hypertension (high blood pressure), and Haemorrhage. Fetal complications include increase risk for prematurity and fetal death, cerebral palsy and low birth weight. If there is a triplet pregnancy, we strongly recommend fetal reduction to singleton or twins.
A rare risk (about 1%) of hormone therapy is the risk of Ovarian Hyper Stimulation Syndrome (OHSS). OHSS is a complication that occurs when the ovaries over respond to stimulation and produce an excessive number of eggs. OHSS is more often seen in younger women and women with polycystic ovaries. Symptoms range from mild to severe and may include nausea and/or vomiting, abdominal distension and discomfort/ pain, shortness of breath, edema (swollen feet), and blood changes. OHSS can last for a few days or for a few weeks and usually resolves on its own, but is considered serious and requires close monitoring and treatment of symptoms. Often women with OHSS need to be admitted to hospital and may need drainage of fluid that collects in the abdomen During treatment every effort is made to observe for signs of OHSS – if these are seen, gonadotropin dosage may be lowered or even the treatment cancelled, in order to avoid the risk of OHSS.
Egg retrieval carries a very low risk of complications, but may be associated pelvic infection in 1/500 cases and with significant bleeding in 1/1000 cases.
There is also risk of ectopic pregnancy with IVF. An ectopic pregnancy is one in which the embryo begins to grow outside the uterus. The embryo is often located in the fallopian tube but can sometimes be found in the ovary, cervix, or elsewhere in the abdomen. The risk of an ectopic pregnancy is slightly higher after IVF (5%) compared with spontaneously conceived pregnancies (1.6%) because women having IVF have a higher chance of having blocked or damaged tubes.
Finally, there is a slightly higher risk of problems during pregnancy following IVF compared with spontaneously conceived pregnancies – although the reasons are unclear and may be due to many factors, such as the age of the mother, the cause of the infertilit and the infertility status of the patient itself. These concerns should be discussed with your physician.
|
