By Dr Pratap Kumar
Udupi, Jan 7: A test-tube baby is a term that refers to a child that is conceived outside the woman's body, in the laboratory. The first successful test-tube baby was born in England in 1978 and since then over 8 million test-tube babies have been born worldwide. The process is referred to as in vitro (outside the body) fertilization. To explain in simple way eggs are removed from the mother’s ovary and incubated with sperm from the father in an artificial womb in the laboratory. After fertilization, the 'pre-embryos' are allowed to divide 2-4 times and then returned to the mother’s uterus where they can develop normally. This procedure is one of many Assisted Reproductive Technologies (ART) that are used when conception has not been otherwise successful due to fertility problems of either the mother or father or both.
Pregnancy is always a matter of chance. For normal fertility, sperm deposited in the vagina must swim up through the cervix, uterus and fallopian tubes to meet an ovulated egg that has been carried from the surface of the ovary to the mid-part of the fallopian tube. The embryo that results (strictly speaking it is still a 'pre-embryo') develops for three days in the fallopian tube, then travels to the uterus, where it floats and develops for another three or four days, before attaching to the lining of the uterus – thus establishing a pregnancy. A few days before the period is missed, a blood pregnancy test will be positive. It is at about this time of implantation, a week after fertilization, that the first few cells in the centre of the 'embryo' actually differentiate into what will be the foetus; all the other cells go to form the afterbirth or placenta.
The general reasons a couple may be relatively infertile (with a reduced monthly chance of conception) or completely infertile (with no chance of conception, sometimes called sterility) are:
Problems with ovulation (the release of the egg from the ovary): There will be complete infertility if periods are absent (amenorrhoea), although many such patients will be treatable with hormones or drugs. If there are no responsive eggs in the ovaries (ovarian failure) the only treatment possible is if someone else donates eggs or embryos.
Problems with sperm production: There will be complete infertility if there are no sperm in the ejaculate (azoospermia), though problems due to blockages (in the sperm passage) are becoming treatable with assisted conception.
A blockage between the vagina and the ovary, preventing fertilization (the commonest site of blockage is the fallopian tubes – sometimes treatable with microsurgery, otherwise with assisted conception).
Endometriosis, a common condition in which tissue like the lining of the uterus (the endometrium) grows outside the uterus, hampering a number of events important to conception and implantation of the embryo in the uterus; treatment can be medical, surgical or with assisted conception; infertility is usually relative rather than complete.
The following tests can be done:
- Hormone levels in the blood
- A sperm count (semen analysis)
- An X-ray of the uterus and fallopian tubes (a hysterosalpingogram) or
- A laparoscopy to look at, and test the openness of, the tunes, and also to look for endometriosis.
These tests may show:
A. Complete infertility (sterility): that is,
(a) Ovarian failure, with no chance of inducing ovulation;
(b) Complete absence of sperm (azoospermia); or
B. Relative infertility: that is, one or more of
(a) infrequent ovulation or absent ovulation resolved partly by treatment;
(b) A decrease in the sperm count;
(c) Partial blockages of the tubes or the presence of scar tissue around the tube or ovary;
(d) Endometriosis of any degree;
(e) An abnormality of the uterus such as fibroids, polyps or scarring of the lining;
(f) An abnormality of the cervix such as a previous cone biopsy or inflammation.
(g) An immune reaction against sperm cells (anti-sperm antibodies) in male or female.
(h) Some of the tubal causes
Dr Pratap Kumar & Embryologist Dr. Satish Adiga with First IVF Baby in 1999
Not many of these abnormalities can be treated easily. Furthermore, the more of these abnormalities that exist together the harder it is to use effective treatment that does not disrupt other aspects of reproduction.
Sometimes no abnormality is obvious: Unexplained infertility is a form of relative infertility. Some causes of infertility can be overcome with simple drugs or with an operation by an infertility specialist. The aim of this treatment is to return your chance of getting pregnant to a more normal level: time will still be needed for a chance to have its way.
Otherwise assisted conception may be needed. Assisted conception means using reproductive technology to considerably increase the chance of pregnancy in the month it is carried out.
Classification of assisted conception
Intra Uterine Insemination (IUI) is a simple less invasive technique in which the husband or donor sperm is placed in the womb using a catheter. IUI is indicated for the treatment of low sperm count or unexplained infertility. Using appropriate laboratory technique, the sperm can be separated from the seminal fluid and re-suspended in a small volume of the sterile medium which will keep the sperm alive and actively motile.
In vitro fertilization (IVF) was invented to overcome untreatable obstruction or absence (after surgical removal) of the fallopian tubes. But this is done for unexplained infertility or other initial measures fail. To obtain enough eggs for IVF, the ovaries are stimulated with the hormone for two weeks.
The eggs are obtained directly from the ovary, about two hours before intended ovulation, by aspirating follicles through the vagina with the help of ultrasound. The eggs are then fertilized in the lab by adding sperm to the culture dish containing the eggs, Two days later few early embryos are transferred into the uterus through the cervix.
Because of the way that sperms are brought into immediate contact with eggs with IVF, fertilization is usually assured, and developing embryos are transferred to the uterus. The chance of pregnancy is up to about 40% per cycle of treatment, depending on the age of the woman.
In extreme cases of sperm defects, especially when only a few normal sperm can be isolated from the ejaculate (or, if necessary, obtained directly from the testicles), micromanipulation is used to insert the sperm directly into the egg (ICSI = Intra Cytoplasmic Sperm Injection).
Donor sperm and donor egg are advised for the women experiencing failure of their ovarian function and women over age 40 with poor quality eggs, the use of donated eggs from their sister or another female may be the best option to achieve conception. The semen bank located at infertility centres provides donor sperm for use in IUI and IVF when the husband has no sperm or if he has genetic disorders.
Modern doctors are most comfortable when their patients understand their medical problem and understand the limitations of their treatment. Results are never certain, and doctors today should share uncertainties with their patients. This way sensible decisions on medical treatment can be made.
IVF and ICSI etc can increase the chance of getting pregnant about 4-5 fold in the month the treatment is carried out. Whether this will result in pregnancy depends in part on what the chance was without treatment and in part, still, on luck. Every decision should be a personal one, taking account of needs, anxieties, priorities and alternatives. It is a decision to be made with your partner, with your family, and with your doctor.
However, modern technology has revolutionised the management of infertility and has definitely helped many couples to have babies.
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