In vitro means "in glass" and that is where conception takes place in a petri dish, using sperm which have been obtained by masturbation and ripe eggs, surgically removed from the ovaries. Today, the dish is more likely to be made of plastic. IVF is the only medical resort for women with irreparably damaged or blocked fallopian tubes.
Similarly, women with conditions of the ovaries, such as endometriosis or adhesions, which prevent ripe eggs from being released, could be candidates for IVF. Male infertility, manifest in a low sperm count, can be an indication for IVF, as can mucus-sperm incompatibility.
How you qualify for IVF treatment
Both partners should be in sound health, mentally and physically. Long-term medication which could interfere with one or more of the complex procedures may mean that IVF is not advisable.
You have to have plenty of time to devote to the single-minded pursuit of pregnancy. This is no "wham, bam, thankyou, ma'am" procedure. You will be counselled, and advised of the emotional and physical trauma of taking part in a program, including the possibility of failure. If you get the green light, you and your partner may be required to have further tests to ascertain such vital factors as whether there is sufficient concentration of sperm to enable fertilisation of an egg and whether it is possible for eggs to be collected. Blood tests also are carried out.
Now begins the time in limbo. After acceptance on to a publicly funded program, it can take months before treatment actually starts.
The onset of your period signals the start of the race to become pregnant. You may be required to have an ultrasound to satisfy the medical team that your ovaries are cyst-free. Your blood will be tested to check hormone levels and you'll receive injections of follicle stimulating hormone (FSH) to encourage the development of more than one follicle (a sac-like ring of cells which protects the maturing egg), thus enabling several eggs to be released. This procedure is called superovulation and, in the IVF stakes, the more eggs collected, the better the odds of having at least one fertilised.
Women and their partners have described the effects of these "rampaging hormones": a woman can be become irrational, tired, depressed or display any number of other uncharacteristic symptoms, so be prepared. Your partner's patience will be tried and he may experience feelings of inadequacy as he watches you going through this undeniably trying time.
However, he can make a vital contribution by providing semen to be frozen for future use. This is essential if he is likely to be away or otherwise unable to donate "fresh" semen when the alarm sounds on your monthly biological clock.
Meanwhile, ultrasound will be used to show the size of the ovarian follicles and so determine how many eggs are developing and when they are likely to be ripe. Hormone levels are monitored daily.
If all is satisfactory, an injection of human chorionic gonadotrophin (HCG) will be given to pinpoint the time of ovulation 38-40 hours later. (HCG is the hormone which, in early pregnancy, is produced by the embryo to prevent menstruation and thus ensure its survival.) This gives the medical team a head start on the ovaries and enables them to remove the eggs just hours before they would have been released naturally.
This is a case of first, find your eggs. The collection process is known variously as aspiration, egg pick-up, egg retrieval and oocyte (literally, "egg cell") collection.
There are two methods of egg collection. In the first, eggs are aspirated through a small cut in the abdomen, using laparoscopy and under general anaesthetic.
Sydney IVF developed another procedure called transvaginal follicle aspiration which obviated the need for both a cut and general anaesthesia. Guided by ultrasound, a hollow needle, or catheter, is introduced via the vagina into the uterus, then along the fallopian tube. The needle is inserted into each ovarian follicle and the follicular fluid is drawn up (aspirated) into it hopefully, along with a ripe egg.
For the most part, this procedure is carried out under local anaesthetic and a mild sedative is given to help you relax. Occasionally, a general anaesthetic is required.
After microscopic examination to ensure that the eggs are healthy, they are placed in a dish with a comparatively small number of sperm about 50,000 to 100,000 either freshly obtained or thawed from frozen.
Introductions complete, the matchmakers retire and the prospective parents pin their hopes on this in vitro coupling.
Although the environment is artificial, there is nothing false about the moment when conception takes place. The earth may not move, yet, for the parties involved, the event is as momentous as an eruption of Krakatoa. When the strongest, most aggressive sperm reaches its destination and penetrates the wall of the egg, human potential is established. Sperm and egg each contain 23 chromosomes, the blueprints for the human being of whom, if the mating is successful, they will form the nucleus.
Some 22 hours later, in a process called syngamy, these will combine into a single cell, called a zygote, containing 46 chromosomes. Fertilisation has occurred; a new life has begun.
For cells which take so long to mature to the stage where they can unite, after fertilisation things happen with indecent haste. The 46-chromosome cell immediately divides into two to become an embryo, then cells continue to divide and multiply until the minute, 32-cell being is ready to take up residence in the uterus which will nurture and protect it for the next nine months.
Embryos conceived in the body take four or five days for their journey along the fallopian tube; IVF embryos usually are considered ready for transfer into the uterus after about 48 hours. Sometimes zygotes, or pre-embryos, are transferred to a fallopian tube, provided it's healthy.
If several eggs have been fertilised, under the guidance of the medical team the couple will have to decide how many embryos to have implanted. They will be offered the option of having some frozen for future implantation or for donation to other infertile couples.
Many specialists believe that only two embryos should be implanted because of the increased risk to babies of multiple pregnancies. Triplets, for example, are more likely to be born prematurely, suffer medical complications and die prematurely than single or twin babies.
Pregnant at last
The embryo transfer is no more uncomfortable than one of the dozens of vaginal examinations you have undergone in the months or years of pursuing pregnancy. Strictly speaking, no anaesthetic is necessary but, if you find it impossible to relax, you may be given a mild sedative.
The embryo(s) will be placed in a fine catheter which is inserted into the vagina, through the cervix and high into the uterus, possibly guided by ultrasound. They will be gently deposited there and the catheter withdrawn. Especially if ultrasound hasn't been used, the catheter will probably be examined under a microscope to make sure the embryos have been left behind.
After lying down for a few hours (the length of time varies between programs), you will go home and wait for the next miracle: the implantation of the embryo(s) in the wall of the uterus.
Unlike other couples who have to wait until a missed period signals the likelihood of pregnancy, you have the advantage of knowing that at least one of your ova has been fertilised and you are carrying an embryo in your uterus. This is a two-edged sword. On the one hand is the excitement that comes with this knowledge; on the other, the anxiety that the embryo will not implant and will be expelled at the end of your menstrual cycle.
For this reason, many women choose to rest for the couple of weeks after the embryo transfer and some programs advise it. Also, you should abstain from sexual intercourse until you get the all clear.
A pregnancy test will be carried out about two weeks after the egg transfer. If it's positive, like all pregnant couples, you will experience a sense of unreality. After all, you don't feel any different and you don't look any different.
On the whole, your pregnancy will be handled in much the same way as any other, although perhaps you will be asked to undergo more ultrasound scans than someone who has conceived naturally. The first of these will be performed about a fortnight after pregnancy is confirmed, to ascertain how many embryos have implanted, and to make sure they are healthy and developing in the uterus rather than a fallopian tube or elsewhere.
As a multiple pregnancy has an increased chance of premature delivery, if more than one embryo has implanted, your doctor will keep a closer eye on you than if you were carrying one baby.