Infertility means inability of a couple to conceive. Infertility is a common problem in our society to the extent that every one is closely known to at least one couple experiencing difficulty in achieving pregnancy.
When we call a couple infertile
The physiology of conception is such that in a given month the man is able to produce a pregnancy throughout, while the woman is fertile only during a specific period of 3-4 days. If they happen to meet on these days the pregnancy is likely to occur early, but if their style of life is such that they have a chance to be separate in these days (e.g. One of the partners has outstation visits), then the pregnancy may take some time to occur. Under normal circumstances 85% of the couples wishing to conceive having regular intercourse and not using any method of contraception will conceive within 12 months. Hence it is quite appropriate to start treatment after one year of marriage. This does not apply to the couple not living together (husband/wife living outstation or abroad), not having regular intercourse or using any method of contraception. The treatment may be started earlier than 12 month under special circumstances where one of the partners has a known cause of infertility. The treatment may also be started early if one of the partners has to go away or there is family pressure, but in that case the intensity of investigations and treatment is kept low.
How The Pregnancy Occurs
A normal woman has a uterus, and one fallopian tube and ovary on its either side. The ovary is a source of eggs. On average one follicle (water sac) matures to a size of 18-25 mm in either of the ovaries every month. The follicle contains an egg. At maturity, which is usually on day 14 of the menstrual cycle (Counted from the start of menstruation), the follicle ruptures spontaneously and the egg is released. The released egg is then taken up by the fallopian tube. The sperms deposited in vagina at intercourse ascend in the genital tract of the woman on their own to reach the fallopian tube, where they meet the already present egg. The egg is fertilized by one of the sperms in the outer half of the fallopian tube. The fertilized egg then travels towards the uterus and reaches its cavity in next 3-4- days, where if finally grows for rest of its tenure. For a pregnancy to occur a couple therefore needs timely deposition of good quality semen from husband into a normal vagina, patent and normally functioning fallopian tubes and a normal Uterus.
What Are The Causes Of Infertility
The infertility may be due to a defect in the husband's semen, failure at intercourse or infrequent intercourse. On woman side there may be a problem in egg formation. The tube may be damaged or blocked. The uterus may be congenitally small or defective, or it may be deformed by fibroid or damaged at previous treatments. The vagina may be congenitally defective.
A group of patients have normal tests for infertility and still they do not conceive on conventional treatment. They frequently ask for the reason for infertility. Such patients must understand that technology so far is able to detect gross defects in fertility process and it yet has to learn a lot about physiology of conception especially at microscopic level. The egg can't be seen on ultrasound directly. It is only judged by the size of follicle which contains the egg. The egg may not be present in the follicle, may not release from follicle upon its rupture, and may not be taken up by the tube. The sperms may not ascend the uterus to fallopian tube. Even if the egg meets sperms in the tube but it may not be fertilized. The fertilized egg may not get implanted in the uterine cavity. All these steps are not visible on ultrasound. Till the time a test is devised to diagnose these problems such patients would be called as cases of unexplained infertility. The important point about these cases is that they have highest chances of success in test tube baby treatment.