| How is sub-fertility investigated? |
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Before laboratory investigations are performed, a full medical history from both partners is taken. Some of the information that is required are as below:
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| The Woman |
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- Age
- Previous pregnancy history, including terminations of pregnancy
- Menstrual history (regularity, any bleeding in between periods and after sex)
- Severe dysmenorrhoea (period pain) which may suggest endometriosis or adhesions (scarring)
- Medical history including medicines taken
- Surgical history (previous abdominal or pelvic surgery for example ovarian cyst, appendicectomy) which may suggest pelvic adhesions
- Smoking, alcohol and excessive caffeine intake
- Obesity which significantly reduces fertility as well as increases miscarriage rate
- Coital history
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| The Man |
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- Medical history (post-pubertal mumps)
- Surgical history (particularly surgery on the testicles)
- Sexual history, including whether any other partner has become pregnant
- Previous STIs (sexually transmitted infections)
- Smoking, alcohol and excessive caffeine intake
- Coital history including erectile or ejaculatory problems
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A cause may become apparent after taking the history. Further assessment by a gynaecologist or infertility specialist may become necessary. Otherwise, some simple investigations can be performed to further assess:
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- The sperm
- The oocytes (egg)
- The fallopian tubes and uterus (tubes and womb)
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| The Sperm |
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The basic laboratory test for the man is the semen analysis. The man should abstain from ejaculation (masturbation or sex) for two to three days prior to the test, as recent ejaculation gives falsely low sperm counts. He is then advised to collect the semen by masturbation and into a clean, sterile container. The specimen should be taken to the laboratory within an hour of collection.
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| The Result: |
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The WHO (1992) criteria are most commonly used. . Normal parameters are as follows:
Volume 2-6 mls
Viscosity liquefaction within 1 hour
PH 7-8
Count 20 million/ml or more
Motility 50% or more
Morphology 30% normal forms or greater
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| The Oocyte (Egg) |
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A woman with a regular period is most likely to be ovulating. Nonetheless, as ovulation is essential to conception, it is important to confirm its occurrence objectively. There are different ways of confirming ovulation:
a) Basal body temperature
This is an easy, inexpensive method, which can be performed home. On waking, a specially graduated thermometer is used to determine the core body temperature and the reading recorded on a graph. This is done daily over the whole menstrual cycle.
As the hormone progesterone level goes up after ovulation in the second half of the cycle (luteal phase), the basal temperature increases about 0.2 to 0.4 °C in the last twelve to fourteen days of the cycle. A biphasic graph with a lower temperature in the first half and an elevated temperature in the second half of the cycle indicates ovulation. The couple can then time their intercourse at the most fertile time.
However, this method is rather time consuming and adds stress. Therefore, it is not used in most cases.
b) Luteinising hormone monitoring
Commercially available home testing kits (ovulation kits) now make it easy to determine the presence of the LH surge, which triggers ovulation. The mid morning urine is tested in the days leading to ovulation and a positive test is an indicator of impending ovulation.
c) Mid-luteal serum progesterone
After ovulation, a corpus luteum is formed from the ovulatory follicle and this produces progesterone. The level peaks between seven and nine days after ovulation and a blood test can be taken during this time. The finding of an elevated progesterone level confirms ovulation. However, the timing of the test can be difficult because the menstrual cycle length can vary month to month, and a negative test may indicate that the test was mis-timed.
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| Maximising the chances of a pregnancy. |
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| The Fallopian Tube and Uterus |
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The gold standard is laparoscopy and dye test but a hysterosalpingogram (HSG) will often suffice. Both these tests are usually requested after referral to a specialist.
A laparoscopy and dye test is a surgical procedure done under a general anaesthetic by inserting a telescope-like instrument just below the umbilicus to view the pelvic organs. A blue dye is then instilled from the cervix and the surgeon views the fallopian tubes to see if there is any spillage of blue dye from the tubes. At the same time he/she can also ensure that the pelvic organs are normal and exclude endometriosis and adhesions.
A hysterosalpingogram involves instilling some radio-opaque dye through the cervix. A series of X-Rays are taken as the dye fills the cavity of the womb and spills through the fallopian tubes. This test is normally done by a radiologist.
A hysterosonosalpingography is an alternative test for tubal patency. This is advantageous because it does not involve exposure to X-Rays and does not involve an operation. A small plastic tubing is first inserted through the cervix and then some normal saline (salt water) is instilled. A trans-vaginal scan is simultaneously performed to visualise the pelvic organs. Using Doppler ultrasound, the tubes can be assessed for any spill of the saline, indicating that they are patent.
This test is available at FMGC.
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