Table of Contents
What is the objective of the fertility tests?
The fertility tests can assess the general gynaecological health of the female reproductive system. This can be done using high-resolution ultrasound scans along with fertility blood tests.
Our fertility scan can check the general health of your womb and ovaries including information about the follicles and the potential of the ovaries to provide eggs, called the ovarian reserve. This can be combined with our fertility blood tests which can further include information about the ovarian reserve. The information can then be used in conjunction with a fertility specialist to provide you with further guidance regarding your fertility.
What is Fertility?
Fertility is defined as the ability to conceive children. Subfertility is defined as reduced or impaired fertility, or the production of fewer offspring than is normal or average. Infertility is the inability to conceive children.
Many factors are needed to work correctly for both partners in order to successfully conceive. These factors include age, weight, sexually transmitted infections (STIs), smoking, environmental factors such as exposure to certain pesticides, heat or solvents and stress.
In women, specifically, other factors also have an effect. They include ovulation disorders such as polycystic ovaries, thyroid problems and gynaecological disorders including problems with the womb (uterus) or fallopian tubes, scarring from surgery, medicines and drugs.
In men, other factors include abnormal semen, testicular problems, hormonal problems, medicines, drugs and alcohol.
Fertility problems affect 1 in 7 couples in the UK, around 3.5 million people. For most couples, engaging in regular unprotected sex is all it takes to become pregnant, however knowing the basic facts about fertility can often be very insightful and helpful in conceiving.
Your monthly cycle – the low down
Every month hormonal changes in a woman’s body cause an egg to be released from her ovaries. This egg travels into the fallopian tubes, which connect the womb to the ovaries. Conception is most likely to occur if unprotected sex occurs a day or so after ovulation. In many women, ovulation takes place around 14 days after the first day of her last menstrual period (LMP).
For conception to occur the sperm must fertilise the egg within 12-24 hours after it is released, however as sperm can live inside a woman’s body for up to 7 days, an egg can, therefore, get fertilised by sperm that entered the body before the egg was released. text-justify
How long does it take to get pregnant?
- 90-92% of couples in which the female is under 30 will conceive after one year of having regular unprotected sex. The risk of miscarriage for women under 35 is around 6%.
- 75-80% of couples in which the female is between 35-39 will conceive after one year of having regular unprotected sex, however, the risk of miscarriage increases to around 15%.
- For women in their early 40s, the chances of conception further decrease to around 50-60% with the risk of miscarriage increasing to around 23%.
As women age they will become less fertile and have a lower quantity and quality of eggs, potentially reducing the chances of conceiving children and increasing the chances of miscarriage. Certain medical problems in the past such as ectopic pregnancy or surgery can also affect fertility.
If you have been trying for more than a year and have not been successful then it is useful to seek advice from a healthcare professional who can perform tests such as hormone blood tests and an ultrasound scan to identify possible fertility problems.
Subfertility & Infertility
Common causes of subfertility and infertility that affect women include age, cancer treatment, lack of regular ovulation, blockage of the fallopian tubes, endometriosis, certain lifestyle factors such as stress, and sexually transmitted Infections (STI).
- Age – As a women’s age increases the number and quality of eggs in her ovaries decreases. This reduction can have an effect on fertility as there are potentially fewer eggs that are suitable to be fertilised.
- Menopause – A women’s biological clock is always ticking. Sooner or later her menstrual cycle will come to a stop as the number of eggs in the ovaries reduces to a few thousand. This change is called menopause and in most instances occurs in the 40s or 50s. There is, however, no specific age that menopause develops.
- Miscarriage – Unfortunately data from recorded miscarriages show more than 1 in 5 pregnancies ends in miscarriage.
In around 25% of couples, the cause of fertility problems cannot be found and is unexplainable.
What is Ovarian Reserve?
As mentioned age is one of the most important factors when estimating the probability of conception as it is a strong determinant of egg quality and quantity. Each woman is born with all the eggs she will ever need. The number of these eggs constantly decreases with age and by the time she undergoes menopause the store is depleted. Screening tests can check how many eggs remain in a woman at any given point in time, however, cannot provide information about the quality of the eggs. Age is currently regarded as the best test for egg quality.
These tests performed to check the number of eggs is often referred to as ovarian reserve, which essentially refers to the remaining egg supply or storage of the ovaries at a given period in time.
What are antral follicles and why are they important?
Follicles are small fluid sacs that contain an immature egg, found in the ovaries. During ovulation, a mature egg is released from a mature (dominant) follicle. Antral follicles are small follicles present in the ovaries that we can see during the transvaginal ultrasound scan. These follicles are typically very small, between 2-10mm, and can be regarded as ‘developing’ follicles which contain an immature egg. These follicles can potentially produce a mature egg and ovulate in the future. The amount of these follicles is indicative of the number of developing follicles remaining in the ovary and thus provides a guide on the number of eggs. The fewer the number of visible antral follicles, the fewer eggs remaining. Conversely the higher the number of visible antral follicles, the higher the remaining eggs. As already mentioned as a woman ages, she will naturally have fewer eggs remaining, therefore, having fewer antral follicles.
During the ultrasound, these small follicles are counted, providing a quantitative figure called the antral follicle count (AFC). This information, along with female age is currently considered by far the best tool for estimating ovarian reserve.
Also in IVF, the number of eggs retrieved correlates with IVF success rates and chances of IVF success. AFCs are also a good predictor of the number of mature follicles that will be able to stimulate with medicines used in IVF.
What is Anti-Mullerian Hormone (AMH)?
Women are born with a lifetime supply of eggs, and these gradually decrease in both quality and quantity with age. Anti-Mullerian Hormone (AMH) is a hormone secreted by cells in developing egg sacs (follicles). The level of AMH in a woman’s blood is generally a good indicator of her ovarian reserve.
AMH is a hormone found in the blood. It is produced by cells in the ovarian follicles during reproductive age. These follicles have different stages of development from their earliest “sleeping” stage to a mature stage where it has produced and released a mature egg. AMH is first produced in the very early stages of a follicle’s life cycle. At this stage, these tiny follicles that make AMH are only visible under a microscope and cannot be seen on an ultrasound. AMH increases and is highest in the preantral and antral stages of development (typically less than 4mm in diameter). As small antral follicles further develop AMH production falls and eventually stops once it reaches over 8mm.
Measurement of AMH is not dependent on the stage of the menstrual cycle and can be performed at any time.
Why is Anti-Mullerian Hormone (AMH) important in fertility?
AMH is only produced by the smallest of follicles in the very early stages of development, which cannot be seen on an ultrasound scan. Therefore by checking the levels of AMH it is possible to measure the size of the pool of growing follicles in a woman which reflects the size of the remaining egg supply or “ovarian reserve”.
Unfortunately, AMH does not provide an indication of the egg quality.
Women with higher AMH values will tend to have a better response to ovarian stimulation for IVF and therefore have a greater number of eggs retrieved and in general, the more eggs retrieved gives a higher success rate.