Assisted Reproductive Technologies or ART, include several different techniques or procedures now available to help couples achieve fertility after other surgical and hormonal methods have failed.
These procedures employ techniques that retrieve eggs from the ovary and re-implant them. Fertilization may occur either in the laboratory or in the uterus.
For many couples, ART offers the best hope of achieving pregnancy.
Following is a description of each of these procedures and how they work:
In Vitro Fertilization is probably the best known and most widely used ART procedure.
For well over a decade, IVF has allowed infertile couples the chance to conceive and bear children.
The best candidates for IVF are women with damaged fallopian tubes.
IVF is a four-stage procedure. The beginning of this process involves ovarian stimulation to produce several mature eggs that can be harvested from the ovary before they have been released from the follicles, and the monitoring and collection of eggs.
Multiple eggs are removed from the woman and placed in a special medium for two to three hours.
The male semen is processed, using different techniques to obtain a vigorous motile sperm. The prepared sperm is then introduced into the medium containing the egg(s).
Many of these eggs will fertilize and develop into embryos, which are then transferred back into the woman’s uterus through a simple procedure that requires no anesthesia.
In most cases, egg recovery is preceded by a period during which the woman receives daily hormone medications to stimulate the growth of multiple eggs.
In some instances, however, it may be possible to accomplish IVF without the use of these ovulation induction medications.
GIFT is an ART procedure developed to assist women, particularly those who have normal fallopian tubes, but there is unexplained infertility. In these cases it can be difficult to determine if the sperm and egg ever meet, so this procedure allows for a site where fertilization is most likely to occur.
This technique is similar to IVF with the exception that the harvested eggs are not fertilized.
The eggs are mixed with the washed and capacitated sperm and immediately placed directly into the woman’s fallopian tubes through a laparoscope (a long thin catheter), thus the sperm and egg are placed exactly where they would be in natural fertilization.
Fertilization then occurs in the woman’s fallopian tubes, after which they move down into the uterus for implantation according to a “normal” timetable.
This procedure is a combination of IVF and GIFT.
The eggs are fertilized with washed and capacitated sperm in the laboratory as in the IVF procedure, but then the beginning-stage embryos are placed directly into the patient’s fallopian tubes as in the GIFT procedure. This blending of IVF and GIFT technique offers the advantage of confirming that fertilization has occurred and the eggs can be examined for defects before implantation.
This procedure also provides the natural environment of the fallopian tubes for the very early conceptus.
Age, is the most important determinant when a woman uses her own eggs.
Rates for ART are relatively high for both pregnancies and live births among women in their 20’s but they decline after 30 and go sharply downward toward the end of the decade and afterward.
The patients who can most benefit from oocyte donation are those who lack ovarian function.
The use of donor eggs has made it possible for many older women, (Success rates using donor oocyte’s depend on the age of the donor, not the age of the recipient.)
This procedure provides healthy eggs from either a known or anonymous donor to women who are unable to utilize their own eggs to achieve pregnancy. Fertilization can be with the sperm of the recipient’s husband to the fallopian tubes of the recipient (GIFT), or the eggs can be fertilized In Vitro with the resulting embryos transferred to the recipient’s uterus (IVF) or to her fallopian tubes (ZIFT).
In cases where more eggs develop into embryos than are going to be transferred to the patient, the couple will have the option of cryopreservation, or freezing, of the embryos for transfer into the woman’s uterus at a later date.
Cryopreservation is used to minimize the risk of multiple births, which increases dramatically if more than four or five embryos are replaced.
Once embryos are frozen in liquid nitrogen and stored, viability will remain unchanged for long periods.
With current freezing and storage methods, 60 to 80 percent of embryos will be viable after thawing. One of the advantages of embryo cryopreservation is that transfer of the thawed embryo may occur in a natural ovulatory cycle.
Intracytoplasmic sperm injection (ICSI) is a highly sophisticated technique for injecting one single sperm into an egg using microscopic and micromanipulation instruments.
In men with low sperm count, low motility or a high number of abnormal sperm, this technique has proven to be a highly successful remedy.
Combined with IVF or ZIFT, the procedure of ICSI is able to achieve a high rate of fertilization and normal embryo development.
ICSI has even been successful in cases where sperm must be taken directly from the testes (testicular biopsy) due to the absense of sperm in the ejaculate or a previous vasectomy.
ICSI is also the best choice when other andrology tests identify a possible problem with sperm function.
This is a procedure of making a tiny hole in the membrane surrounding the embryo before implanting to assist it in attaching to the uterus.
This thinning the membrane of the fertilized egg may increase implantation rates in eggs from certain women, such as those over age 40.
This is a procedure that allows a longer time for the embryo to develop in the laboratory (five days instead of two to three).
This enables the embryo to reach the blastocyst stage, which is the natural embryonic stage for implantation in the uterus.
Many couples undergoing In Vitro Fertilization accept the risk of multiple gestation as an integral part of the treatment process.
They want to maximize their chances of achieving a pregnancy and will transfer three or more embryos to achieve their goal.
After all, the chance of taking home a baby is not 100%, and the cost of an IVF cycle can be quite significant.
Sometimes, the financial resources of a particular couple may only allow them to undergo an IVF cycle once in their lifetime.
The end result of transferring 3 or more embryos has been a significant increase in the rate of triplet and higher order multiple pregnancies. There are enormous medical, social, and financial consequences of this increase in multiple birth rate.
One solution to this problem may be to culture the embryos for 5 or 6 days, to the blastocyst stage.
Embryos developing to the blastocyst stage (blastocysts), have a higher implantation rate than embryos grown only three days, and are more likely to succeed in initiating a pregnancy.
As result, only two blastocysts need to be transferred to have the same pregnancy rate usually seen when 3 or more embryos that have been grown for only 2 or 3 days are transferred into the uterus. In other words, fewer embryos are needed to achieve the same or higher pregnancy rate, resulting in a lower incidence of multiple gestation.