In Vitro Fertilization (IVF) was first successfully performed by Patrick Steptoe, MD and Robert Edwards, PhD in a woman with tubal factor infertility. The woman timed her ovulation and underwent laparotomy for oocyte retrieval. In the ensuing years, spontaneous cycles were replaced by first ovulation induction with clomiphene citrate and then stimulation with gonadotropins. Ovulation stimulation allowed the retrieval of more than one mature oocyte, thus increasing the statistical chance of embryonic implantation during one cycle. The early pregnancy rates were approximately 8% per cycle and cancellation prior to oocyte retrieval was high. The introduction of GnRH analogs allowed down regulation prior to ovarian stimulation and thwarted the numbers cycles cancelled due to spontaneous premature LH surges. GnRH analogs therapy was most likely the reason that IVF pregnancy rates jumped to about 15% per cycle in the late 80's.

By the time IVF was introduced by the Jones in the United States in 1983, oocytes retrieval was primarily by laparoscopy. In 1983, Gleicher et al. reported the first transvaginal ultrasound-directed oocyte aspiration and currently most aspirations are performed in this manner(46).

Initially, IVF was indicated in patients with tubal factor infertility. The relatively high success rates have allowed extension to couples with endometriosis, drug-resistant polycystic ovarian syndrome, and unexplained infertility. Additionally, IVF can be used with donor oocytes to treat women with age-related ovarian dysfunction, ovarian failure or surgically removed ovaries. Combined with ICSI (see below) IVF can also be used to treat couples with sperm disorders and immunologic infertility.

Procedure:IVF begins with ovulation induction. Although it may be performed in natural cycles, this approach requires intensive hormonal monitoring and the availably of the medical team too often to be practical. In addition, pregnancy rates are lower with natural cycle IVF.

A variety of ovulation induction regimens is available. Most programs in the United States administer a GnRH agonist in the luteal phase prior to the cycle of stimulation. Oral contraceptives are often added prior to down-regulation. After spontaneous ovarian activity is suppressed, folliculogenesis is stimulated with gonadotropins. The regimen used is particular to each program, but those that have been tested in clinical trials all seem to result in similar pregnancy and delivery rates. Choices are made based on cost, availability, route of administration, and familiarity of the physician with the regimen.

Gonadotropin releasing hormone antagonists can also be used to thwart spontaneous LH surges during ovulation induction. Thus far, they have not proven superior to the agonists in pregnancy outcome and are more expensive on a mg per mg basis (47).

During ovulation induction, the ovaries are monitored for follicular growth by frequent transvaginal ultrasound examinations and serum estradiol concentrations. When clinical parameters suggest the presence of mature oocytes, human chorionic gonadotropin (HCG) is administered to mimic the LH surge and allow further progression of the oocytes through meiosis. Approximately 35 hours later, the patient undergoes  follicular aspiration. In the United States, most aspirations are performed transvaginally with ultrasound guidance. Either general anesthesia or conscious sedation is used. Regional analgesia is not usually employed because the concentration of the local anesthesia in the follicular fluid has been shown to decrease the pH and affect the fertilization of the oocytes in vitro(48). Concomitant identification of the oocyte by nearby laboratory technicians informs the physician to proceed with aspiration of each sequential follicle (Figures 14,15).

Between 4 and 6 hours after aspiration, the oocytes are mixed with 15,000-30,000 motile, previously prepared sperm. Human fertilization occurs in the next 18 hours and the first two cell divisions usually occur in the subsequent 24 hours (49). The number of embryos transferred depends upon the day of transfer. A few programs transfer 2 days after aspiration and will transfer up to 6 embryos. Most programs wait 3 days and transfer 3 or 4 embryos. Waiting until 5 days after transfer allows the embryos to develop into a blastocyst ; generally 2 or 3 blastocysts are transferred. The American Society of Reproductive Medicine (ASRM) recommends determining the number of embryos to be transferred by patient criteria, patients with a with favorable prognosis generally receiving no more than 2 embryos, and those with a poor prognosis receiving no more than 5 embryos (ASRM Practice Committee Report: Guidelines on the Number of Embryos to Transfer, revised Nov.,1999). In general, younger women have a better prognosis than older. These guidelines were proposed to decrease the incidence of multiple pregnancies, yet still facilitate a favorable pregnancy rate.

The embryos are transferred through the vagina into the uterus. Approximately 2 weeks later a pregnancy test is performed. Because aspiration removes granulosa cells which would otherwise produce the progesterone necessary for endometrial development, many programs support the luteal phase with exogenous progesterone supplementation. This has never been shown to be necessary or effective, but is of low risk (50). If given, supplementation is continued for at least 4 weeks after the positive pregnancy test.

Contraindications:IVF is contraindicated in women in whom pregnancy is contraindicated.

Outcome:Federal law requires that the outcome of all IVF cycles be reported to the national database kept by the CDC. In addition, the American Society for Reproductive Medicine’s subsociety, SART (ASRM/SART) keeps a registry found at www.sart.org.

Overall, IVF outcome in the United States, for aspirations performed in 2004, is 40.1% per aspiration for women younger than 35, 33.4% for women between ages 35 and 37, 23.2% for women between 38 and 40, and 13.2% for women over 40 years.

Gamete Intrafallopian Transfer (GIFT) is a procedure developed in 1983 by Dr. Ricardo Asch in San Antonio (51). The procedure begins in a therapeutic manner similar to IVF; however, when the oocytes are aspirated, they are mixed with sperm and immediately replaced in the patient's fallopian tubes. GIFT requires less laboratory services and expertise than does IVF but does require the patient to incur the risks of general anesthesia and laparoscopy. With increasing training and availability of IVF laboratory personnel, GIFT is becoming less frequently used.

Indications:GIFT requires at least one normal, patent fallopian tube. Patients with unexplained infertility are those who benefit most from this procedure. Additionally, because embryos are not formed in the laboratory, some religious groups may find GIFT more acceptable than IVF.

Procedure:GIFT begins with ovulation induction in a manner similar as described above for IVF (see IVF). When the patient is ready for oocyte aspiration, the aspiration may be performed either transvaginally with ultrasound guidance, or transabdominally under laparoscopic guidance. The oocytes are immediately combined with previously prepared sperm and allowed to incubate for 10 minutes to allow sperm binding to the zona pellucida. Approximately 25,000 motile sperm and two oocytes are placed in each Fallopian tube through a catheter placed in the tube under laparoscopic vision. Luteal support with exogenous progesterone may be given. Two weeks after aspiration a pregnancy test is performed.

Contraindications:Patients with abnormal Fallopian tubes are not eligible for GIFT treatment. Any contraindication to pregnancy is a contraindication to GIFT.

Outcome:Federal law requires that the outcome of all IVF cycles be reported to the national database kept by the CDC. In addition, the American Society for Reproductive Medicine’s subsociety, SART (ASRM/SART) keeps a registry found at www.sart.org.

Overall, GIFT was performed following less than 1% of the aspirations in the United States in 2004, and because of the small number of cases, outcome data specific for GIFT is unavailable. In general, the outcome of GIFT is thought to be comparable to that of ovulation induction with gonadotropins and intrauterine insemination.

Controlled Ovarian Hyperstimulation and Intrauterine Insemination (COH-IUI)Controlled Ovarian Hyperstimulation and Intrauterine Insemination (COH-IUI) was first introduced in 1983 by Dodson et al. as a direct spin-off of GIFT (52). These clinical investigators reasoned that if the cyclic fecundity rate may be increased by placing processed sperm into the normal fallopian tube with 4 oocytes, perhaps the physical placement can be replaced by the patient's natural physiology. Their first series of 85 patients were stimulated with gonadotropins to develop 4 mature follicles and the normal fallopian tubes were entrusted with oocyte pick-up. After administering hCG, processed sperm were delivered into the intrauterine cavity and allowed to be propelled naturally to the site of the oocyte. Previous studies revealed that this transport occurred within two minutes. This therapy was applied to patients with unexplained infertility so rapidly that it resulted in a demand on the supply of urinary gonadotropins so large that a temporary backlog of drugs in the United States occurred.

Indications:Unexplained infertility was the initial indication for COH-IUI. This was later extended to include some patients with pelvic adhesions (but patent tubes) and also patients with male factor infertility.

Procedure:Beginning early in the menstrual cycle, gonadotropins are administered daily to patients. After approximately 5 days of therapy, ultrasound examination of the ovaries and serum estradiol measurements are performed every 1 to 2 days to determine the dose and frequency of further gonadotropin administration. When three to four mature follicles are identified, human chorionic gonadotropin (hCG) is administered to trigger ovulation. Between 24 and 48 hours after hCG administration, an intrauterine insemination (IUI) is performed.

The sperm is prepared for IUI in a manner similar to that first described for IVF. After liquification, the ejaculate is diluted with a buffered media and centrifuged. The sperm is thus separated from the seminal plasma when the supernatant is discarded and the sperm-rich pellet is re-suspended in media. Processing thereafter varies with the laboratory and sperm characteristics. The sperm suspension may be layered in a sephadex column (Percoll®), recentrifuged with media, or allowed to "swim-up" into an overlying layer of media. These procedures are intended to remove non-motile sperm, debris, bacteria, and white cells before intrauterine insemination. They also remove 60-80% of the motile sperm. No technique has proved superior for pregnancy outcome.

Contraindications:Blocked fallopian tubes are a contraindication to COH-IUI because the tubes are required to pick up the oocytes from the ovary and facilitate the mechanical apposition of sperm and oocyte.

Outcome:Pregnancy rates and pregnancy outcome after COH-IUI depend upon diagnosis. Few randomized studies are available to assess accurate outcomes after this therapy because it is often attempted in patients who would otherwise be treated with IVF. For example, a patient with pelvic adhesions who cannot afford IVF may opt for a cycle of COH-IUI in hope that more ovulations may increase the chance of an oocyte being geographically close to the fimbrial opening and afford tubal pick-up, The more ovulated oocytes, the better statistical chance of an oocyte reaching the tubal opening. Nonetheless, patients such as this would be less likely to conceive than a patient with normal tube-egg pick-up.

Strict criteria for unexplained and male factor infertility were applied in the randomized trial conducted by the Reproductive Medicine Network from 1989-1998 (43). This study revealed that patients with truly unexplained infertility had a 33% pregnancy/cycle with COH-IUI, higher than couples treated with either COH or IUI alone, and higher than controls.

The multiple pregnancy rate was 13.4% overall and the spontaneous abortion rate was 19% overall (22.3% in the COH treated groups). Interestingly, this study treated couples with more than one motile sperm and no other infertility factors. In those couples with sperm counts between 0.2 and 21.8 x 10-6, couples were found to have a higher pregnancy rate when treated with COH-IUI than either COH or IUI alone, and higher than controls.