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Assisted Reproductive Technologies (ART)
Several procedures can be used to unite sperm and eggs, thus bypassing altogether some of the factors causing infertility. Collectively, these procedures are referred to as assisted reproductive technologies (ART). Although most couples do not require these procedures to conceive, ART provides hope for those who do not respond to other therapies.
The simplest ART procedures use various medicines to stimulate ovulation and laboratory procedures to prepare sperm cells for insemination at the time of ovulation.
Advanced ART procedures involve the use of various hormones to stimulate the growth of as many oocytes as possible. This multiple oocyte development increases the chances for fertilization and, subsequently, pregnancy. The most common advanced ART procedures include:
- In vitro fertilization (IVF)
- Gamete intrafallopian transfer (GIFT)
- Zygote intrafallopian transfer (ZIFT)
In Vitro Fertilization (IVF)
In vitro fertilization (IVF) was the first ART developed and is the most commonly used ART procedure. It is effective in overcoming a variety of infertility problems, particularly tubal problems or marked sperm problems.
Gamete Intrafallopian Transfer (GIFT)
Gamete intrafallopian transfer (GIFT), developed in 1984, is another ART procedure used to assist infertile couples. The procedure is based on the speculation that in some cases of infertility, the sperm and egg do not arrive at the site of fertilization–the fallopian tubes.
GIFT involves the stimulation of ovaries to produce multiple eggs, which are retrieved with ultrasound guidance, and transfer of these harvested eggs combined with sperm to the fallopian tubes by laparoscopy immediately following collection.
Up to four of the highest quality eggs are transferred during the procedure. The remaining collected eggs may be fertilized in vitro and resulting embryos can be cryopreserved for later use. GIFT can only be used in patients with healthy fallopian tubes.
In recent years, with the improvement in pregnancy rates from IVF, the extra surgical risk and cost of the GIFT procedure limit its use to a select number of patients.
Zygote Intrafallopian Transfer (ZIFT)
Zygote intrafallopian transfer (ZIFT) or pronuclear stage embryo transfer (PROST) combines aspects of both IVF and GIFT.
Protocols for ovarian stimulation are identical to those used for IVF and GIFT. Eggs are collected and fertilized by the partners sperm in the laboratory.
What makes ZIFT different from IVF is that the embryo is placed into the woman's fallopian tube via laparoscopy instead of the uterus.
As with GIFT, the ZIFT procedure has limited use.
ART Procedures
There are several procedures associated with ART techniques:
Pituitary Desensitization
When discussing ART therapies with the physician, the couple may hear the term pituitary desensitization. This condition is medically induced and shuts down the cells of the pituitary gland that make hormones to affect the ovary.
A desensitized pituitary gland minimizes the chance of a premature LH surge.
Such a surge usually results in a canceled ART cycle because the eggs necessary to continue the procedure cannot be retrieved.
Cryopreservation
Many ART centers now have the ability to preserve embryos not used in a particular ART cycle, for future use.
Once embryos are frozen and stored, they remain viable for long periods of time.
About half of frozen embryos will survive thawing and can be transferred.
Cryopreservation enables some embryos to be used in the ART cycle and some to be stored for future use in a natural cycle (a cycle without hormonal stimulation).
Cryopreservation may also lower the cost of subsequent ART procedures because the first few stages (ovarian stimulation, egg retrieval) do not have to be repeated when the frozen embryos are used.
Micromanipulation
In men with radically reduced sperm numbers or immotile and abnormal sperm, the success of IVF has been limited.
When sperm quality is severely compromised (i.e. poor count, poor motility or poor survival), microsurgical intervention, such as gamete micromanipulation, may be used.
This procedure involves IVF combined with a microscopic procedure directed at increasing the chance of fertilization.
It is especially effective for men with very low sperm count or in couples who have not found success with routine IVF.
ART Success Rates
The experience of couples undergoing the cycles of advanced assisted reproductive technology (ART) are provided within subgroups based on maternal age.
Also, cryopreservation of embryos with subsequent thaw and transfer has become common. The recent experience for such cycles is also provided.
The likelihood of success leading to the birth of a live infant is influenced by multiple factors. Couples considering these technologies should consult with specialists in reproductive endocrinology for advice on the most appropriate procedures and likelihood of a successful outcome.
All ART for most recent 200 initiated cycles with assessments to at least clinical pregnancies regardless of method, IVF and ICSI.
| Age | <35 | 35-39 | 40+ | Total |
| # Cycles initiated + | 114 | 61 | 25 | 200 |
| # Retrievals (% of cycles initiated) | 97 (85) | 48 (79) | 15 (60) | 160(80) |
| # Retrievals resulting in fertilized embryos for transfer or cryopreservation (% of retrievals) | 93 (96) | 44 (98) | 15 (100) | 155 (97) |
| # Transfers (% of retrievals) * | 90 (93) | 44 (92) | 15 (100) | 149 (93) |
| # Clinical pregnancies (% of transfers) | 48 (53) | 19 (43) | 7 (47) | 74 (50) |
| # Pregnancy loses (% of clinical pregnancies) | 5 (10) | 4 (21) | 3 (43) | 12 (16) |
+ Patients responding too rapidly or too slowly discontinue stimulation and return later to reinitiate with reduced or increased dosages of hormones
* Sometimes conditions occur that place patients at increased risk for complications if embryo transfer is conducted in the treatment cycle. In such cases, embryos are cryopreserved to transfer in a subsequent spontaneous or artificial cycle.
Thaw of cryopreserved embryos for most recent 50 cases regardless of maternal age and number of embryos available for transfer
| Total | |
| # Cycles initiated + | 58 |
| # Cycles with embryos thawed (% of cycles initiated) | 50 (86) |
| # Transfers (% of cycles with thawed embryos) | 50 (100) |
| # Clinical pregnancies (% of transfers) | 21 (42) |
| # Pregnancy losses (% of clinical pregnancies) | 2 (10) |
+ Sometimes conditions occur during initial phase of cycle that suggest reduced potential for successful outcome. In such cases, embryos are not thawed, but continue to be stored for transfer in a subsequent spontaneous or artificial cycle.
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