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Getting pregnant may not always be a walk in the park for a lot of women, including many in Singapore where the total fertility rate continues to decline. Many women are facing roadblocks in trying to conceive and, unfortunately, they are unaware of the importance of fertility health checks. 

Singapore Fertility Rate

Source: Department of Statistics Singapore

An infertility diagnosis, albeit discouraging, is a reality to be reckoned with, especially if you plan on having a baby. Knowing what’s hampering you from getting pregnant will guide you and your doctor toward the right measures for correcting the problem. Since the biological clock waits for no one, it helps greatly when you act as sooner than later.

Before any treatment process can be initiated, the doctor must first arrive at a diagnosis, which we will be discussing in this post. 

What determines female fertility?

Perhaps one important aspect of female fertility is the egg factor. By the time you start menstruating, you will have half a million egg follicles left. 

An egg follicle is a sac that holds one egg. At the beginning of each menstrual cycle, the first few developing follicles are considered candidates for ovulation within that cycle. However, midway through the follicular phase, one follicle becomes dominant—a lot like a star athlete who stands out from the team. All resources go into “grooming” this single follicle while the others are left to die off. Imagine this happening every month, so by the time you hit 30, you lose 90% of your eggs. And by the fourth decade of life, you would’ve lost up to 97%. In time, these eggs will run out, eventually leading to menopause

Egg Follicle

Read: Managing Menopause: A Quick Guide On What To Expect When You’re Expecting

Going back to our “superstar follicle,” once it is ready, it releases the egg, which then travels out of the ovary and into the fallopian tube. After it is released, the egg has about 12-24 hours to be fertilised by sperm. If it doesn’t get fertilised in that short window, the egg begins to degrade. But if it gets fertilised, it travels to the uterus over the next 5-6 days to become a potential implant for pregnancy. 

Menstrual Cycle

What is infertility?

The World Health Organization (WHO) defines infertility as a “disease of the reproductive system” marked by a failure to achieve clinical pregnancy even after a year of trying. It is further classified into two: 

  • Primary infertility – wherein women have not conceived after at least a year of having sex even without the use of birth control methods
  • Secondary infertility – wherein women who have previously given birth are unable to get pregnant again or carry a baby to term 

Infertility diagnosis in women

There’s a variety of diagnostic tests done specifically on women to determine the cause for low fertility or outright infertility. One of the first things that are checked is the ovarian reserve. It sums up a woman’s chances of conceiving based on her current egg supply. Women with low ovarian reserves make fewer eggs. Hence, they have a lower chance of getting pregnant even with fertility treatment. A young woman with a lower than expected ovarian reserve (premature ovarian insufficiency) will menopause earlier than her peers. 

Aside from a diminishing number of eggs, the egg quality also tends to decline. However it is hard to check specifically for egg quality. A healthy egg has the ability to create a chromosomally normal embryo and hence fetus, which reduces miscarriage risk but is heavily dependant on the woman’s age. During an IVF procedure, the egg (and sperm) quality will determine the quality and number of surviving embryos but there isn’t a good predictor outside of the scope of IVF apart from general predictions based on age. At the age of 37 years old, the rate of chromosomal abnormality in the eggs is approximately 40%. The rate rises to 50% at 40 years old and almost 90% by 44 yrs. Hence the rate of decline in egg quality (and hence increase in miscarriage) is exponential. 

Decline in fertility rate

Ovarian reserve and quality can be tested in a variety of ways, mainly through imaging and blood tests. These tests can tell your OB or infertility specialists about your egg quality, egg reserves, and structural problems that may make conception challenging. Take a look at the different investigations below. 


1. Antral Follicle Count (AFC)

Antral (small) follicles measure 2-8 mm in diameter. They can be seen, measured, and counted by ultrasound as part of a fertility workup. To get an accurate assessment of the number of resting follicles, a transvaginal ultrasound (preferably between day 2 to 5 of the cycle) is performed. 

Interpreting the images obtained is fairly straightforward but it’s not possible to determine the total number of follicles since some are too small to be detected by ultrasound. Having just a few antral follicles developing in the ovaries indicates that the corresponding number of eggs are also low. 

Besides evaluating ovarian reserves, an AFC also gives an idea of where fertility stands in relation to age. It also identifies primary ovarian insufficiency (POI), and can help diagnose polycystic ovarian syndrome (PCOS). An ultrasound also screens for uterine polyps and fibroids or abnormal ovarian cysts that impact fertility.

Read: 10 Common Causes of Infertility in Women

2. Hysterosalpingogram (HSG)

Hysterosalpingogram (HSG)

HSG is an X-ray test that can check the size and shape of the uterine cavity, but it is done mainly to check whether the fallopian tubes are partially or fully blocked. 

A blockage is often caused by a scar tissue that may form inside the pelvis or around the fallopian tubes due to endometriosis, pelvic infection or previous abdominal or gynaecological surgery causing scarring. Any obstruction in the tubes inhibits the sperm from reaching the egg, which is one of the common reasons why women find it hard to get pregnant.

In HSG, a thin tube is threaded through the vagina and cervix. A contrast medium, or a dyed solution, is introduced into the uterus and fallopian tubes. When viewed on an X-ray screen, the dye shows up in contrast to the body structures as it outlines the inner size and shape of the uterus and fallopian tubes. Women with open tubes will have what’s called a free spill. The dye will spill from the ends of the fallopian tubes–showing that they are open or patent. Any blockage or stoppage of the dye, which can also be seen also through x-ray, indicates occlusion of one or both tubes. The HSG may also detect uterine polyps or scarred tissue within the cavity that can affect implantation.

3. Saline Hysterosonogram

Saline Hysterosonogram

Also called a sonohysterography, a saline hysterosonogram procedure may be ordered to evaluate the shape of the uterine cavity. The process is like a gynecologic exam involving the insertion of a transducer into the vagina after you’ve emptied your bladder. Through a small tube, which is also inserted into the vagina, a small amount of sterile saline is injected into the cavity of the uterus to study, so the doctor can study the lining using an ultrasound transducer. This procedure can determine if there are any polyps, fibroids, or other uterine abnormalities; and provides a clear picture of the soft tissues, which are clearly visible in x-ray images.

The alternative to evaluate the cavity is there is a suspicion of a uterine abnormality on regular vaginal ultrasound is to perform a short day surgical procedure called a hysteroscopy, dilation and curettage with polypectomy to remove a polyp or fibroid that is obstructing the cavity. It allows for an immediate therapeutic removal of the source of the problem while fully evaluating the cavity. 

Blood Tests

4. Follicle Stimulating Hormone (FSH) Screening 

FSH is produced by the brain to help regulate the menstrual cycle and egg production. FSH levels fluctuate throughout the cycle and as such, these are tested early in the cycle, usually around the second or third day. It can help the doctor gauge a woman’s ovarian function and evaluate the egg quantity. If results show elevated FSH levels, it means that a woman has lower ovarian reserve as the brain is trying to compensate for the poorer number of follicles by producing more FSH to stimulate their growth.

FSH screening may be used with other hormone tests for luteinizing hormone (LH), estradiol, and/or progesterone levels are useful in:

  • determining the cause of infertility ( eg checking for successful ovulation)
  • diagnosing pituitary or hypothalamic disorders of the brain that can affect FSH production.

Often thyroid, prolactin levels and certain vitamins and minerals will also be tested to exclude hormonal imbalances and certain nutritional deficiencies that can affect fertility.

5. Anti-Mullerian Hormone (AMH) Testing

AMH is a protein made by the granulosa cells, which surround the follicle. Each follicle has thousands of granulosa cells completely engulfing and nourishing the egg. Having more eggs means more follicles, which consequently results in higher AMH levels. As you age, you will experience a natural decline in AMH levels, until it totally runs out when you hit menopause.

AMH is considered a strong indicator of the ovarian reserve because the levels stay fairly consistent throughout the menstrual cycle, and can be tested on any day. AMH levels can also be a dependable guide in choosing the ideal fertility therapy. 

However, it is important to know that AMH does not predict pregnancy success but, rather, the ovaries responsiveness to an egg-freezing cycle or in-vitro fertilization (IVF) cycle. In general, women with higher AMH levels require less medication for stimulation and often generate a larger quantity of eggs ( and hence embryos).

Overall, the key intent in checking ovarian reserve is for fertility doctors to counsel women on the chances of success with fertility treatment. But know that screening doesn’t stop there. To pin down the root cause of infertility, your partner needs to undergo testing for you to get the full picture. 

Read: 6 Ways to Improve Your Chances of Getting Pregnant Fast

Infertility diagnosis in men 

Since one third of subfertilitiy is due to male factor and another one third due to combined male and female factors, it is important to check the male partner.

Semen analysis is an important test to check for sperm concentration, shape, movement, quality, infections, colour, or the presence of blood. This can also determine any infection in the reproductive system, such as Chlamydia, which can affect fertility. If semen analysis results are abnormal, a repeat test and additional blood tests may be ordered to identify the potential problem. 

If the results are poor, further blood tests can help point to the causes of male infertility because it can check the levels of testosterone and other hormones. Imaging can also check for any anatomical issues such as a blockage. For this, a scrotal ultrasound can be done to reveal issues such as varicocele, ejaculatory duct obstruction or retrograde ejaculation. 

So, if you have been trying to get pregnant for a year and remain unsuccessful, it’s time to take the next step and consider fertility testing. Know what’s holding you or your partner from conceiving. Get professional help and submit to necessary tests to find a suitable treatment for infertility.

If you have any questions, you may call +65 6254 2878 or drop us a line, here.

Dr Pamela Tan
About Dr Pamela Tan

Dr Pamela Tan is a board certified obstetrician and gynecologist in Singapore. She finished her undergraduate studies at the National University of Singapore and earned her post-graduate degree at the Royal College of Obstetricians and Gynaecologists in the UK. She is an accredited specialist by the Specialist Accreditation Board (Ministry of Health), and a fellow of the Academy of Medicine, Singapore. She subspecialises in colposcopy and is certified to perform Level 3 minimally invasive keyhole surgeries such as laparoscopic hysterectomy, myomectomy and cystectomy. Dr Pam also supports the natural birthing method and she strives to provide a personalised care and treatment for each patient.