Reproductive Assistance: What Is In Vitro Fertilization?

In 1978, British researchers Robert Edwards and Patrick Steptoe broke reproductive ground with the birth of the world’s first “test-tube baby,” little Louise Brown. Now, in vitro fertilization (IVF) is a relatively common procedure used to treat a variety of infertility causes.

Literally translated from Latin as “fertilization in glass,” the in vitro fertilization process uses the tools of the scientist–petri dish, microscope, sterile environment–to create life from two human cells, the sperm and oocyte.

While the technology used is incredible, the steps followed are simple:

  • Regulation of female cycle through the use of contraceptives, Lupron, or Synarel (GnRH agonists)
  • Ovulation induction through the use of injectable fertility medications containing Follicle Stimulating Hormone (FSH), such as Gonal-F, Follistim, Pergonal, Repronex, or Metrodin
  • A “backup” semen sample collected from the male to be frozen and stored in the event of problems with collection later in the cycle
  • Close monitoring via ultrasound and bloodwork of the woman’s egg production to determine timing of the remaining steps (in addition to protecting against ovarian hyperstimulation, a potentially life-threatening but rare consequence)
  • Administration of human chorionic gonadotropin (hCG) via injection in preparation for ovulation
  • Egg retrieval via needle aspiration with the assistance of vaginal ultrasound
  • Primary semen sample collection via masturbation on the day of egg retrieval
  • Insemination and fertilization follow as eggs and sperm will be combined in petri dishes
  • Depending on the needs of each patient, some of the following procedures may be used to facilitate fertilization: assisted hatching, ICSI
  • Approximately 72 hours after egg retrieval, transfer of optimally-developed embryos into the uterus via a small tube through the vagina and cervix
  • The woman is asked to refrain from most physical activity for the next 48 hours, and a pregnancy test will be administered approximately two weeks after egg retrieval

Who Benefits From It?

IVF was initially created for cases in which blockage of the fallopian tubes is the primary problem, as these represent a large percentage of female infertility situations. As the techniques have become more polished and the physicians and technologists more skilled, IVF has come to be seen as an alternative for numerous forms of infertility. For example:

  • Men who’ve had vasectomies and want to conceive again, with the additional assistance of MESA/ICSI
  • Other situations of male-factor infertility which would require ICSI for fertilization to occur
  • Women who’ve had tubal ligations and don’t want to go through surgical reversal
  • Unexplained infertility that has not responded to other types of assisted reproductive techniques
  • Some cases of endometriosis
  • Cases which require Preimplantation Genetic Diagnosis (PGD) for several genetically-transmitted conditions

What Are The Stats?

One of the most common questions is regarding the incidence of multiples resulting from IVF. Indeed, the incidence can be higher than with unassisted conception (as high as 25% for twins), and the exact rate depends on many variables. Some of these variables, such as how many embryos are transferred into the uterus, are controllable by the patient through good communication with her physician.

In some countries, the number of embryos transferred is controlled by a governmental entity, such as the Human Fertilization and Embryology Authority (HFEA) in the United Kingdom. In the UK, law permits the transfer of up to three embryos. The International Federation of Fertility Societies (IFFS), made up of affiliated societies from virtually every country with IVF access, also concurs with a maximum of three transferred embryos. In the United States, no such laws exist; however, the American Society for Reproductive Medicine (ASRM) recommends that no more than two embryos be transferred in cases with “good” prognosis for pregnancy, and up to five embryos for remaining cases, depending on the prognostic level. For more details, refer to their related Practice Committee Opinion (PDF viewer required).

The next most common question is regarding the pregnancy rate of IVF. As with any other assisted reproductive technology, there are no guarantees and plenty of variables with which to contend. The notable variable factors include:

  • Maternal age
  • In the case of surrogacy or donor egg, the age of the surrogate and donor
  • Quantity of produced embryos
  • Quality of produced embryos
  • Number of previous failed treatment cycles
  • Sperm morphology
  • Condition of the uterus and its lining
  • Existence of other structural factors, such as hydrosalpinx (a form of tubal blockage)

Implantation rates after embryo transfer are generally in the range of 20%, according to the IFFS. In their 1998 Fact Sheet, the ASRM states that IVF’s live birth success rate is 22.8% per egg retrieval.

Pregnancy rates also can vary significantly from clinic to clinic, and patients should take care to be wise medical consumers. Consult the latest gatherings of statistical data via governmental sources such as the Centers for Disease Control (CDC) in the U.S., the Australian Institute of Health and Welfare’s National Perinatal Statistics Unit in Australia/NZ, or the HFEA in the UK. Also check for clinic recommendations from the various infertility consumer support and advocacy groups, such as RESOLVE, American Infertility Association, ACCESS, Australian Infertility Support Group, and the Worldwide Infertility Network.

In general, according to the ASRM, the risks of IVF are as follows:

  • Allergic reactions to medications–Rarely
  • Ovarian hyperstimulation–Less than 1%
  • Needle aspiration related injury–Very rarely
  • Anesthesia complications–Rarely
  • Miscarriage–Approx. 20%, same as general population and primarily age-related
  • Ectopic pregnancy–Slightly higher than general population

In just a few decades, its success has led in vitro fertilization from what seemed like “weird science” to being a bona fide method for helping couples conceive.