For Anna and her husband, this proved to be the case. She underwent IVI (in-vitro insemination), in which viable eggs were taken from her ovaries, fertilised in a laboratory, and resulting embryos transferred to her uterus.

“The first couple of embryos didn’t ‘take’, but the third did, and we now have a son,” Anna says. Now aged 47, she says she and her husband were concerned because of her age and condition.

“It was an emotionally exhausting period for us,” she adds. “I cried a lot because I longed for a child of my own and couldn’t bear another disappointment. My husband and I had spent a lot of money on the fertility treatment and we prayed very hard for just one embryo to make it.”

Joan and her husband were not as lucky: inflammation from her condition created an unfavourable environment for fertilisation. “I’ve exhausted all my options to fall pregnant. Having tried for a baby for some years now with no success, my husband and I have resigned ourselves to the likelihood that we’ll never have kids of our own.”

“We use the term ‘unexplained’ when doctors have assessed the couple but still can’t pinpoint the reasons they can’t conceive,” Dr Ong says.

Age is one of the main reasons why women have difficulty conceiving. “As a woman’s age increases, her ability to become pregnant to term decreases,” Dr Wong explains. “Between the ages of 30 and 35, a woman’s chances of falling pregnant gradually decline and after age 40 there is a sharp decline.” With age, there is a progressive decrease in ovary reserves and the quality of a woman’s eggs.

Other reasons for sub-fertility in women include failure to ovulate, fallopian tube blockage which prohibits fertilisation, or problems with the uterus.

Men may experience conditions that affect their sperm production and transportation, including erectile dysfunction, hormone imbalances, and chromosome defects. Medications such as exogenous testosterone, chemotherapy drugs and steroids can also affect a man’s sperm if taken over a long period of time, Dr Wong says.

A recent study at Justus Liebig University Giessen in Germany also found urogenital infections to be a possible cause of irreversible infertility in males. Caused by sexually transmitted pathogens (bacteria, viruses or other microorganism that can cause disease) or uropathogens (a microorganism capable of causing disease of the urinary tract), these infections were found to affect a man’s testes as well as his sperm count.

“The results of this study are not surprising,” says Dr Ong. “Urogenital infection is common in males in Hong Kong, however the Department of Health has not been able to come to a consensus about the effectiveness of screening for such infections. If you’re concerned that you have a urogenital infection and wonder how this might affect your fertility, you can walk into any Social Hygiene Clinic to get tested and treated for it.”

Dr Wong agrees that urogenital infection may be a possible cause of male infertility, but she does not believe it’s a major cause, contributing to less than 10 per cent of cases.

How long should a couple try for a baby before becoming concerned about your ability to fall pregnant? “A couple is considered sub-fertile if they still haven’t conceived after about a year of having frequent unprotected sex,” says Dr Ong. “If the woman is aged 35 and over, she and her partner should try for six months.” Dr Wong adds that a woman over the age of 40 who has tried to fall pregnant for six months should see her gynaecologist as soon as possible. Any delay may lower the chances of any fertility treatment being successful.

If either partner has a condition that may affect the ability to start a family, such as a previous ectopic pregnancy or surgery, they should seek medical advice. Such risk factors for sub-fertility must be identified, Dr Ong points out. “It doesn’t mean that there’s no hope for you and your partner to have a baby, but it’s wise to get medical help beforehand.”

To determine the best treatment, a doctor will assess both partners for medical problems, evaluate their medical history, and run tests. For women, Dr Wong says these may include a blood test to check their ovary reserves, an ovulation test, an ultrasound sonography test for structural abnormalities in the pelvic region, and radiological imaging to test for fallopian tube blockages. Men may have to get their sperm tested.

Two common treatments are IUI (intra-uterine insemination) and IVI. In IUI, a catheter is used to insert sperm into a woman’s uterus to facilitate fertilisation, and is sometimes combined with fertility drugs. It may be prescribed if the man has a low sperm count, decreased sperm mobility, or suffers from ejaculation dysfunction, or if the woman has a condition that impedes her partner’s sperm from entering her uterus. Dr Ong says for this procedure, it is preferable for both fallopian tubes to be unblocked, although if only one tube is blocked, the procedure can still work.

Slightly more invasive is IVI, since eggs must be harvested from the ovaries, fertilised in the lab and then replaced into the uterus.

Regardless of whether a couple is at risk of sub-fertility, there are straightforward steps to take when trying to conceive. Dr Wong advises both partners to stop consuming alcohol and stop smoking completely, learn how to manage emotional stress, keep their weight under control, exercise regularly, get at least seven hours sleep every night, and eat a healthy diet of foods that are high in antioxidants.

Women should take a folic acid supplement – Dr Wong recommends 400mcg daily, while men should avoid wearing tight underwear, as this may increase the temperature of the scrotum, inhibiting sperm production.

“Women should also monitor their cycle and be aware of when they are ovulating,” Dr Ong adds. “Having regular, unscheduled sex can also help. Regular may mean twice or thrice a week, or more frequently, like every other day.”