Understanding infertility: What every couple should know about testing and treatment
Despite a common assumption that conception is automatic, normal fertility does not guarantee pregnancy in every cycle. Even among healthy couples, the chance of conceiving in any single cycle is only about 20–25 per cent.
What you need to know:
- Clinically, infertility is defined as the inability to achieve pregnancy after 12 months of regular, unprotected intercourse for individuals under 35, or after six months for those aged 35 or older.
- It is a widespread condition, affecting approximately 17 per cent of the global population: roughly one in every six people.
Despite affecting millions of lives worldwide, infertility remains a deeply taboo subject. It is an intensely personal journey, often shrouded in misconceptions that leave couples and individuals navigating it in silence, pain, and anxiety.
Clinically, infertility is defined as the inability to achieve pregnancy after 12 months of regular, unprotected intercourse for individuals under 35, or after six months for those aged 35 or older. It is a widespread condition, affecting approximately 17 per cent of the global population: roughly one in every six people. While prevalence rates are notably similar across both high- and low-income countries, access to advanced fertility testing and treatment varies significantly worldwide.
Infertility is categorised as either primary or secondary. Primary infertility refers to individuals who have never achieved a pregnancy, which may indicate underlying reproductive challenges. Secondary infertility, on the other hand, applies to those who have been pregnant before (regardless of the outcome) but are now unable to conceive. This form often stems from factors that emerge over time, such as new infections, age-related reproductive changes, or scar tissue from surgery.
Despite a common assumption that conception is automatic, normal fertility does not guarantee pregnancy in every cycle. Even among healthy couples, the chance of conceiving in any single cycle is only about 20–25 per cent. However, this likelihood accumulates over time: roughly 50 per cent of couples conceive within six months of trying, while approximately 80–90 per cent achieve pregnancy within 12 months.
Age remains the most significant factor affecting fertility, particularly for women, as both the quantity and quality of eggs decline more rapidly after age 35. Concurrently, the risk of chromosomal abnormalities rises, leading to lower implantation rates and a higher likelihood of miscarriage. Other major contributors include medical conditions like diabetes and thyroid disease, as well as pelvic infections that can damage the fallopian tubes. Lifestyle choices also play a crucial role: smoking can damage sperm DNA and accelerate egg loss, excessive alcohol consumption impairs reproductive health, and chronic stress disrupts the hormonal balance essential for reproduction. Additionally, being significantly underweight or living with obesity can interfere with fertility, with obesity often linked to irregular ovulation.
Couples are generally advised to seek medical help after 12 months of regular, unprotected intercourse without achieving pregnancy when the individual trying to conceive is under 35, or after six months when they are 35 or older. An immediate fertility evaluation is recommended at age 40 or above, or when either partner has a known risk factor such as irregular menstrual periods, pelvic inflammatory disease, endometriosis, previous pelvic surgery, or male fertility concerns like erectile dysfunction. Early assessment in these circumstances can help identify potential problems sooner and improve the chances of timely, appropriate treatment.
Infertility is rarely caused by a problem affecting only one partner. Female-related factors, including ovulation disorders, blocked fallopian tubes, and uterine abnormalities are involved in approximately 35–40 per cent of cases. Male-related factors, most commonly issues with sperm count, motility (movement), or morphology (shape), are the sole cause in about 20–30 per cent of couples. Because reproduction is a shared process, both male and female factors contribute simultaneously in an estimated 30–40 per cent of cases. In a further 20–30 per cent of couples, the condition is classified as unexplained infertility, meaning that standard diagnostic tests appear normal despite continued difficulty conceiving. These figures may overlap depending on how cases are classified, but they reinforce an essential point: identifying a fertility issue in one partner does not rule out contributing factors in the other. For this reason, both partners should always be evaluated at the same time.
Also read: Infertility affects your sex life. This is how to bring the kick back as you try for a baby
A standard fertility evaluation assesses both partners concurrently using high-yield, minimally invasive tests. For men, the initial test is usually a simple and cost-effective semen analysis, which measures semen volume and evaluates sperm count, motility, and morphology. Delaying this test is a common mistake as male factors may contribute even when no symptoms are apparent. The female evaluation focuses on three main areas: ovulation, ovarian reserve, and reproductive anatomy. A mid-luteal progesterone blood test can help confirm whether ovulation is occurring regularly, while ovarian reserve, the estimated remaining egg supply, is assessed using a pelvic ultrasound and an Anti-Müllerian Hormone blood test. Finally, ultrasound imaging and a hysterosalpingogram are used to examine the uterus and determine whether the fallopian tubes are open.
Irregular menstrual periods, endometriosis, and uterine abnormalities can affect fertility through different mechanisms. Irregular periods often indicate inconsistent or absent ovulation and may be associated with conditions such as polycystic ovary syndrome (PCOS), thyroid disorders, or elevated prolactin levels. Endometriosis, in which tissue similar to the uterine lining grows outside the uterus, can create inflammation that interferes with egg quality, sperm function, fertilisation, and implantation; it may also cause adhesions or scar tissue that distort or restrict the reproductive organs. Uterine abnormalities, including submucosal fibroids, endometrial polyps, and intrauterine scar tissue associated with Asherman syndrome, can alter the uterine cavity and make it more difficult for an embryo to implant and develop successfully.
Once the cause of infertility has been identified, treatment is tailored to the individual or couple, as there is no one-size-fits-all approach. The doctor will help weigh expected success rates, costs, potential risks, and the likelihood of complications such as multiple pregnancy.
Ovulation problems are generally treated in stages, beginning with appropriate lifestyle changes and progressing, when necessary, to oral ovulation-induction medications, injectable hormones, or in vitro fertilisation (IVF). IVF is often preferred for severe tubal disease or advanced endometriosis as it bypasses the fallopian tubes. When a blocked tube is filled with fluid, a condition known as hydrosalpinx, the affected tube may need to be surgically removed or isolated before IVF because the fluid can reduce embryo implantation and treatment success. Structural abnormalities such as submucosal fibroids and uterine polyps may be corrected surgically, while cervical factors, including poor-quality cervical mucus, can sometimes be bypassed through intrauterine insemination (IUI).
When standard tests find no clear cause, the diagnosis is unexplained infertility, which accounts for about 20–30 per cent of cases and may involve subtle fertilisation or implantation problems. Younger couples may initially continue trying with timed intercourse or fertility tracking, while women over 37 are often advised to consider treatments such as IUI or IVF sooner. Although infertility cannot always be prevented, risks can be reduced by preventing sexually transmitted infections, treating conditions such as thyroid disease or endometriosis early, avoiding smoking, maintaining a healthy weight, and consulting a fertility specialist when tests are abnormal or advanced treatment is needed.
Dr Okemo is assistant professor, Aga Khan University Medical College and Consultant Obstetrician Gynaecolgist at Aga Khan University Hospital
