Understanding some of the basic tests for fertility problems
The term ovulation implies release of an egg from the egg sac (follicle) of the ovary. This usually occurs mid-cycle i.e. day 14 of a 28 day cycle, but the day of ovulation can vary from month to month. Generally, women who have regular periods are ovulating, however, this becomes more dysfunctional and irregular as a woman gets older.
Eggs are released when they are mature and this is dependent on the size of the follicle, which grows from a few millimeters at the start of a period to around 20mm+ at the time of ovulation. The maturity of the follicle or egg is related to the amount of the hormone estrogen the ovary produces before ovulation, and progesterone after ovulation.
As such, whether ovulation has occurred can be determined by measuring progesterone (blood test) and it is usually at its peak one week after ovulation. The body temperature also rises after ovulation in response to progesterone, however, this is an unreliable method of assessing ovulation.
Another way of checking if ovulation has occurred is by doing an “ultrasound scan”. This will show a change in the follicle from which an egg has been released known as the corpus luteum.
Tubal problems - blocked tubes - affecting fertility:
The Fallopian tube captures the ovulated egg from the ovary and transports it to meet the sperm, which after fertilization becomes and embryo. The embryo then travels down the tube and implants in the womb leading to pregnancy.
If there is a blockage or restriction of the tubes, this will reduce the chances of the egg and sperm meeting, therefore preventing fertilization and pregnancy occurring.
The most common cause tubal problems are sexually transmitted infections such as Chlamydia or gonorrhea and pelvic inflammatory disease (PID). Other causes of tubal problems include endometriosis, scarring due to abdominal or pelvic surgery and appendicitis. As such, the woman’s past history is important in understanding their risk of having a problem with the Fallopian tubes.
A blood test for past Chlamydial infection (serology) is also a useful screening test. Otherwise testing by X-ray known as Hysterosalpingography (HSG), contrast ultrasouns (HyCoSy) or laparoscopy may be required depending on the individual circumstances.
Male factor (sperm problems)
Sperm or male factor problems are the main cause of infertility in 30% of couples and suboptimal parameters are found in the male partner of up to 60% of couples with fertility problems.
A history of undescended testicles, epididymo-orchitis (infection of the testes), testicular trauma, varicocoele or previous genitourinary surgery is relevant to men with fertility problems as is a history of cystic fibrosis. In some cases there is a hormonal problem that could be corrected with medication. However, in most cases where sperm problems are found the cause is uncertain.
There are two facets to sperm problems, one of sperm production, the other sperm function. Sperm production is easy to measure by doing a sperm test otherwise known as seminal fluid analysis. Function is more difficult to assess.
Unfortunately the sperm test is only really useful if there is a significatn problem i.e. if the count is low or the sperm move slowly. The world health organization has published criteria, which determine whether sperm tests are within the normal range. However, research has shown that these measurements are not the most predictive of fertility.
As such, some men with low sperm counts are fertile and some with normal counts are found to have difficulty with fertility. In specialist clinics more advanced tests can be undertaken to assess sperm function.