Egg Timer Test
The Egg Timer TestThe egg timer test estimates ovarian reserve – the number of good quality eggs left within the ovaries.This gives an indication of the likely fertility status of a woman.The test involves a single blood test organised by our doctor, and a trans-vaginal ultrasound between days 3-5of the menstrual cycle. The blood test measures levels of several different hormones, and combined with the scan result gives an estimate of ovarian reserve.
Many women delay starting a family for various reasons.However, fertility declines with age and difficulties conceiving may develop. An early indication of fertility status may help on deciding whether to start a family sooner or later.
As a woman gets older, the quality of her eggs decline resulting in an increased risk of genetic abnormalities leading to an increased risk of miscarriage. Abnormalities such as Down syndrome are also more common in babies born to older mothers.
The fertility of a 35 year old is half that of a woman less than 30 years while the fertility of a 40 year old is only a quarter of a woman less than 30 years. High blood pressure, low birth weight babies, bleeding in late pregnancy, diabetes and early delivery are all at least double in pregnant women older than 40 years.
The rate of loss of good quality eggs from the ovaries does vary between women. Most women are born with approximately one million eggs. Over their reproductive life only 400 of these eggs are ovulated, with the remainder undergoing natural cell death. The rate of spontaneous egg loss does vary between individuals and at different stages in a women’s reproductive life. Given that 10% of women go through early menopause before the age of 45 years we can expect that these women will experience a rapid decline in fertility due to an accelerated loss of eggs from 32 years of age. It is this 10% of the female population who are at high risk of “reduced ovarian reserve related infertility” if they delay conception until their mid to late 30’s.
In the majority of cases of premature ovarian ageing, no risk factor will be identified. However, the known risk factors are:
- Family history of early menopause (before 45 years of age)
- Surgery to the ovaries or fallopian tubes
- Endometriosis (A condition where endometrial tissue- lining of the uterus, is found at various locations outside of the uterus)
- Pelvic infection
- Cancer treatments (chemotherapy and radiotherapy)
- Vegetarian diet
- Previous low number of eggs retrieved in an IVF cycle
The egg timer estimate is only able to act as a guide to the production of good quality eggs left within your ovaries. Research has been able to correlate egg timer results with the number of eggs produced during IVF treatment and pregnancy outcome.
Subsequently, the egg timer provides women with an enhanced estimate of their “ovarian reserve”. Women diagnosed with polycystic ovarian syndrome (PCOS) aren’t suitable as this condition interferes with the results. If PCOS is detected during the egg timer test you will be advised to discuss the implications with your doctor as proper diagnosis of PCOS involves blood tests and other diagnoses.
Women taking the oral contraceptive pill need to stop this for a full month prior to the egg timer test. The pill can be recommenced immediately after the test has been done. After the one month break, the pill is not fully effective until 7 hormone (active) pills have been taken.
Women over 40 years of age would expect to have reduced ovarian reserve and the test may indicate what is already a known factor. Even if an egg timer test is normal we advise women to discuss with their doctor the risks of delaying pregnancy.
Once the ovaries run out of eggs, the body isn’t able to produce any more, and it usually leaves the lowest quality eggs till last. Even IVF treatment will not dramatically improve fertility if there are only a few poor quality eggs left within the ovaries.
If you find you have a low ovarian reserve, the best option is to go ahead and try for children as soon as possible. If a woman does undergo premature menopause, using donor eggs is a viable option that is currently available through fertility clinics. Freezing of eggs following IVF is possible but the technology is relatively new and the pregnancy rate quite low. Freezing of ovarian tissue for transplanting at a later date is still experimental.