Infertility – Two sides of the story
Fertility and infertility are the result of complex functions of the human body. A great number of events and conditions have to be just right and working together in order to achieve a pregnancy. So it’s not really surprising that as many as one in six couples will experience some degree of infertility.
Degrees of fertility
Infertility can be “complete” (also called “sterility”), which means you absolutely cannot get pregnant without help. Or it can be “incomplete”, also called “subfertility”, which means that there’s no absolute barrier, but the odds are reduced compared with normal, and getting pregnant might take more time.
A normal, fertile couple in their 20s having regular sex would have a monthly chance of pregnancy of about 20%. Pregnancy would be expected within 4-6 months of trying. When a year has passed without successful conception, the monthly chance of pregnancy is evidently much lower than this, and you should consider seeking help.
There need not be a major reproductive condition to affect fertility levels. Even minor disturbances, especially in combinations, can cause the monthly chance of pregnancy to be much reduced.
To illustrate the effect of multiple, minor factors in infertility, a model can be constructed to estimate the chance of pregnancy per month and the amount of time it will on average take to get pregnant:
Number of mild factors |
Monthly chance |
Estimated time to a pregnancy |
0 |
20% |
4 months |
1 |
5% |
2 years |
2 |
1% |
7 years |
3 |
0.2% |
40 years |
It is easy to see that it doesn’t take much to reduce the chance of pregnancy quite significantly. Perhaps a slightly low sperm count and mild endometriosis? Even with two mild cases of such common conditions, the expected time to conception could be up to 7 years.
Infertility and you
The most important thing to remember is that there is help when nature fails. The technology we have today was developed because infertility is such a common problem. You are not alone. It is your choice what course of action you should take, and at Sydney IVF we try to do everything we can to help you make an informed decision about dealing with your infertility.
Fertility and age
Because women are born with all their eggs for their entire life already formed (unlike men, who produce new sperm for most of their life), by the time women approach 40, their eggs are not as viable as they once were. It is believed that their biggest problem at this age is that they lack the energy it takes to transform from a fertilized egg to an embryo that can implant in the lining of the uterus and continue on to form a normal fetus. More errors are made during egg production as women age. This can produce pregnancies with chromosome errors, like Down's Syndrome. A noticeable drop in pregnancy rates is seen in women over the age of 34. This pregnancy rate falls even more rapidly over the age of 40, and pregnancy with IVF is rare after 42.
Fertility and genetics
In some cases the cause of infertility has a genetic origin. Some people can have a chromosome rearrangement which doesn’t affect them at all, because they have all the genetic material. When it comes to making sperm and eggs, though, this rearrangement can mean that some sperm or eggs have too much of one chromosome and not enough of another. This means that the resulting embryo won’t have all the genetic information it needs to develop properly and it may not survive or could result in an abnormal baby. Chromosome rearrangements can turn out to be the cause of failed fertilizations and repeated miscarriages.
Solutions to the problem
Because female age is one of the biggest contributing factors to the incidence of infertility today, the obvious answer is to try not to leave it too late to have a family. This is often easier said than done, but it is crucial to realize its importance. Even with the aid of assisted reproductive technologies, women over the age of 40 still have a relatively low chance of conceiving.
For some, medical or surgical treatment is an option. For most causes of infertility, however, there is a form of assisted conception that can overcome the problem. This is especially true if the eggs are young and strong.
For an obstruction of the fallopian tube, endometriosis or a low sperm count, IVF is a highly successful treatment. For extreme male infertility, even with no sperm in the ejaculate at all, the sperm can often be surgically extracted from the ducts (PESA) or the testes (TESE) and microinjected into the egg (ICSI). When there are no eggs or sperm at all, IVF with donor sperm or eggs can be available.
Unexplained infertility can also very often be overcome using IVF technology. Sometimes the cause of infertility can be identified using chromosome analysis on you and your partner. If the cause turns out to be genetic, there are genetic analysis options available that can check for irregularities in IVF embryos.
(Information on this page was provided by Professor Robert Jansen)