Although we think of assisted reproductive technology as relatively new, artificial insemination is an ancient technique, used in livestock as far back as the second century and in human beings as early as the eighteenth century. Although artificial insemination is still used, more sophisticated techniques are available. The three principal techniques of assisted reproduction are Gamete intrafallopian transfer (gamete intrafallopian transfer), ZIFT (zygote intrafallopian transfer), and IVF (in vitro fertilization — fertilization “in glass,” a petridish or other laboratory glassware). These techniques involve harvesting eggs from the ovary. The woman is usually treated with medication to produce and mature more than one egg in a single cycle.

Unless donor eggs and sperm are used, all these techniques require that the woman be able to produce and mature eggs (possibly with hormonal help) and the man be able to produce healthy sperm. With the exception of artificial insemination (AIH and AID), these techniques are done by fertility specialists, often in major hospitals or fertility clinics.

Artificial Insemination

Artificial insemination simply means depositing sperm in the woman’s reproductive tract without intercourse. The sperm can belong to her husband or partner, in which case the procedure is called AIH (artificial insemination with husband’s sperm), or it can be from a donor, in which case the procedure is known as AID (artificial insemination with donor sperm).

How are donor sperm screened?

Years ago, donor sperm were sometimes used live; today, because of human immunodeficiency virus, sperm banks make sure the donor is disease free before his sperm are used. The donor is given blood tests for human immunodeficiency virus, hepatitis, and syphilis at the time of donation. After a six-month wait, during which the sperm are frozen, he is tested again to make sure that his tests have not turned positive. If a donor was infected with human immunodeficiency virus two weeks before he made his donation, his blood test might not yet have turned positive, but it will certainly do so during the waiting period. The down side is that frozen sperm are less potent than fresh and less likely to fertilize an egg. It is an acceptable negative, given the seriousness of sexually transmitted diseases.

Sometimes a lesbian couple will use donor sperm from a male friend, without medical supervision or screening. I strongly advise the couple to be sure that the sperm donor is not infected with hepatitis, syphilis, or human immunodeficiency virus.

How does artificial insemination work?

You go to your doctor’s office at the time of ovulation, which you can determine with an ovulation predictor test. While you are on the examining table in position for a pelvic exam, your caregiver will dilate your vagina with a speculum to isolate your cervix and, with a syringe, place the sperm sample right in the cervical opening. You should remain lying down for fifteen or twenty minutes.

Some women try “home methods” of artificial insemination using donor sperm. They obtain a speculum, a syringe, and an intravenous catheter and inject the sperm through the tubing into the cervix. Women without access to medical devices have been known to use a turkey baster.

How are eggs gathered from the ovary for advanced reproductive technologies?

Usually you start by taking a drug, Clomid or Pergonal, which stimulates the eggs in your ovaries to mature. The choice of drug depends on the physician. Usually Clomid is preferable because it is easier to use and can be taken orally. If Clomid does not succeed, Pergonal is a stronger and more expensive alternative. It must be injected and monitored with blood tests. With Pergonal as many as thirty eggs may ripen and all are harvested. Ultrasound imaging and tracking the blood levels of estradiol, the primary form of estrogen made in the body, can be used to check the progress of maturation.

Harvesting itself is a minor surgical procedure, usually done with intravenous sedation. The ovary, stimulated by the Clomid or Pergonal, becomes heavy with eggs and hangs down near the vagina. The surgeon, guided by ultrasound, puts a long thin needle through the vaginal wall into the ovary and aspirates the eggs into the needle. After the procedure, most women feel sedated by the medication and rest for the remainder of the day. Usually they are able to resume work the next day.

In Vitro Fertilization

How does IVF work?

Once the eggs and sperm are collected, they are mixed together and placed in a glass dish containing a nutritive medium, in the hope that fertilization will take place and some of the eggs will begin to divide. If this happens, the embryo is placed in the uterus with a straw-like device. A pregnancy test two weeks later can determine whether the embryo has been implanted in the wall of the uterus.

Is in vitro fertilization right for you?

In vitro fertilization is an appropriate technique if your tubes are blocked or impaired, perhaps by endometriosis or infection, and if you have had previous ectopic pregnancies. If you are ovulating well but your partner has a problem with sperm production, your eggs can be retrieved and mixed with the sperm of a donor, fertilized, and then replaced in your uterus. On the other hand, if your partner is producing viable sperm, but you do not ovulate at all or do not ovulate well, the option of donor eggs exists. You will need hormonal assistance in addition to the implantation, because your body has to be prepared to receive the fertilized egg.

Occasionally sperm may need help in penetrating an egg. This can be done in a petri dish; the technique is called intracytoplasmic sperm injection, or ICSI.

Gamete Intrafallopian Transfer and Zygote Intrafallopian Transfer

Not frequently used nowadays, Gamete intrafallopian transfer (gamete intrafallopian transfer) is a technique whereby eggs and sperm are placed into the fallopian tubes in the hope that fertilization will take place there. (A gamete is a reproductive cell, either an egg or a sperm.) For this procedure, you must have healthy tubes, though you may have difficulty ovulating. Again, your partner must be able to produce healthy sperm.

The procedure starts off like IVF: your ovaries are stimulated with Clomid or Perg-onal; the eggs are harvested; the sperm are collected. Then both are placed in the open end of one of your fallopian tubes with the help of alaparoscope. Gamete intrafallopian transfer is a more invasive procedure than IVF because it involves an incision for inserting a laparoscope into the abdomen to transfer the eggs into the fallopian tube. IVF simply involves transferring embryos into the uterus through the cervix without surgery.

ZIFT (zygote intrafallopian transfer) is similar to Gamete intrafallopian transfer, except that it is the zygote, the fertilized egg, that is transferred to the fallopian tube, again with the help of a laparoscope. Fertilization takes place in a petri dish in a laboratory. The fertility specialist checks to be sure that the cell division that marks successful fertilization has actually taken place before the transfer is made. As in Gamete intrafallopian transfer, an incision must be made to insert the laparoscope.

Do these assisted reproductive techniques increase the chances of multiple births?

During IVF, usually several eggs are implanted in the uterus in the hope that one of them will take hold, so it is certainly possible to have twins, triplets, or even more births. Data gathered in the Centers for Disease Control and Prevention 1999 survey show that 37 percent of all births with assisted reproductive techniques were multiple births, compared with less than 3 percent of births in the general population. Twins accounted for 29 percent of these multiple births; triplets or larger numbers of infants accounted for 8 percent. Because multiple births pose risks for both the mother (cesarean section) and the babies (preterm delivery, low birth weight, long-term disabilities) laws in some countries, including England, prohibit placing more than two embryos in the uterus.

How successful are assisted reproduction techniques?

As the technology improves, so does the success rate. Some estimates reach 80 percent for couples who are willing to make repeated attempts — which are expensive, time consuming, and emotionally challenging. According to the 1999 data, 25.2 percent of IVF procedures using fresh nondonor eggs resulted in live births, with younger women having higher rates than older ones. Women younger than age 35 had a rate of 32.2 percent live births, while women 41 and older had a rate of only 9.7 percent.

How expensive are assisted reproductive techniques?

Assisted reproductive technology comes at a high price and is not universally reimbursed by insurance. Costs differ from clinic to clinic, but it has been estimated that therapy with Clomid or Perganol costs about thirteen hundred dollars per cycle; the cost of intrauterine insemination (where donated semen is placed within the uterus) is about five hundred dollars per cycle. More sophisticated techniques such as IVF cost in the range of three thousand to ten thousand dollars per attempt and take as long as ten days.

Surrogacy And Other Techniques

Women who cannot produce eggs even with the help of hormonal stimulation and men who cannot make viable sperm do have the option of donor eggs or sperm. This means that women in their late 40s who are nearing menopause can bear a child by using the eggs from a younger woman, fertilized by the older woman’s partner. On occasion, an older mother has borne her own grandchild — her daughter’s egg fertilized by her son-in-law’s sperm — because the daughter had a uterine malformation.

Tagged with:  
Share →