Infertility is a widespread global issue that affects approximately 1 in 6 people of reproductive age worldwide during their lifetime, according to the World Health Organization (WHO). This translates to roughly 17.5% of the adult population. It can be defined as the inability to conceive after a year or two of unprotected sexual intercourse. It is a significant public health challenge that carries profound emotional, social, and economic consequences for millions of individuals and couples, regardless of their location or income.
How does conception occur?
Pregnancy requires the precise synchronization of ovulation and intercourse; an egg must be released from the ovary and encountered by viable sperm within its brief 24-hour fertile window for fertilization to occur. The fertile window is the narrow period surrounding ovulation when the body is biologically prepared for fertilization. This should occur every month in a woman with a regular menstrual cycle. Sperm can live inside the body for up to 5days.
- Primary infertility:
Primary infertility is the medical term used when a person or couple has never achieved a pregnancy after trying for a specific period of regular, unprotected sex.
- Secondary infertility:
Secondary infertility is the inability to conceive or carry a pregnancy to term after having already achieved at least one prior pregnancy.
Causes of infertility
For a long time, a persistent social stigma suggested that infertility was primarily a “female issue”,this is due to a lack of proper knowledge and because she is supposed to carry the pregnancy but modern medical data has thoroughly debunked this myth, revealing a much more balanced reality. Approximately one-third of infertility cases are linked to female factors, one-third to male factors, and the final third is a combination of both or remains “unexplained.” Understanding these causes is the first step toward finding a solution. Simply put studies have placed the causes of infertility as follows;
Male 30%
Female 30%
Combined 10%
Unexplained 25%
Others 5%
Male factor in infertility
This is mainly centered on the health and delivery of the sperm. If there are any issues, it would fail to fertilize the ovum and thus cause infertility. There could be an issue with sperm count, motility, or morphology.
- Oligospermia: a medical term for low sperm count.
- Aspermia: It is a medical condition where a man experiences a complete lack of semen during ejaculation.
- Hypospermia: here an abnormally low volume of semen is produced at ejaculation.
- Azoospermia: here there is an absence of sperm cells in semen.
- Teratospermia: There is an increase in sperm with abnormal morphology.
- Asthenozoospermia: There is reduced sperm motility.
Causes of infertility are divided into:
- Pretesticular causes
- Testicular causes
- Post-testicular causes
Pre-testicular causes: These involve factors outside the gonads that affect sperm production indirectly, usually by disrupting the hormonal signals from the brain (hypothalamus or pituitary gland) that tell the testes to make sperm. They include;
- Hormonal Disorders: Conditions such as Hypogonadotropic hypogonadism, where the brain fails to produce enough FSH and LH to stimulate the testes.
- Pituitary Gland Issues: Tumors like prolactinomas (which secrete excess prolactin) can suppress the hormones needed for sperm production.
- Systemic Diseases: Uncontrolled diabetes or thyroid problems can lead to metabolic changes that impair sperm quality.
- Psychological Factors: Intense stress can release hormones that reduce testosterone levels and hinder sperm production.
- Medications: Certain drugs, such as exogenous testosterone or anabolic steroids, can shut down the body’s natural sperm production through negative feedback.
Testicular causes: These are primary defects within the testes themselves that prevent them from producing healthy sperm. They include:
- Varicocele: Swollen veins in the scrotum that increase testicular temperature and impair sperm production.
- Genetic Conditions: Klinefelter syndrome (XXY) and Y chromosome microdeletions directly interfere with the formation of sperm.
- Developmental Issues: Cryptorchidism (undescended testicles) exposes the testes to high body temperatures, leading to permanent damage if not corrected early.
- Infections: Mumps orchitis (especially after puberty) can cause severe inflammation and permanent scarring of the testicular tissue.
- Injury and Trauma: Physical trauma or testicular torsion (twisting of the testicle) can lead to ischemia and tissue death.
- Gonadotoxins: Exposure to radiation, chemotherapy, or environmental toxins like lead can be toxic to the sperm-producing cells.
Post-Testicular causes: In these cases, sperm is produced normally in the testes, but a problem prevents them from being delivered through the ejaculate. Examples include;
- Ductal Obstruction: Blockages in the epididymis, vas deferens, or ejaculatory ducts can be caused by infections (like chlamydia or gonorrhea), scar tissue from previous surgeries (e.g., vasectomy), or birth defects.
- Genetic Obstructions: Men with Cystic Fibrosis often lack the vas deferens entirely (Congenital Bilateral Absence of the Vas Deferens or CBAVD).
- Ejaculation Disorders: Retrograde ejaculation, where semen enters the bladder instead of leaving the penis, can be caused by diabetes or pelvic surgery.
- Erectile Dysfunction: The inability to maintain an erection sufficient for sexual intercourse prevents the delivery of sperm to the female reproductive tract.
- Sperm Antibodies: Sometimes the body produces antibodies that attack its own sperm, making it difficult for them to move or fertilize an egg.
Female factor in infertility
In women, the most common barrier to conception involves hormonal imbalance or structural blockage:
- Hormonal imbalance:
Hormones are the chemical messengers that control every step in the ovulation process. The hypothalamus and the pituitary gland produce FSH and LH, which tell the ovaries to start the ovulation process. Anything that disrupts the signal to the ovaries would alter this process leading to anovulatory disorders.
Anovulation;This is the absence of ovulation.
Oligoovulation;This is infrequent ovulation.
Anovulatory disorders include;
- Polycystic ovarian syndrome:
This affects approximately 1 in 10 women of reproductive age. It is the leading cause of anovulatory infertility, occurring when an imbalance in reproductive hormones, primarily excess androgens (male hormones) and high insulin levels, disrupts the normal development and release of eggs from the ovaries. The symptoms of PCOS vary widely and can be mild or severe. Common signs include menstrual irregularities, excess hair and acne, weight gain, skin changes, and infertility.
- Hypothalamic-Pituitary dysfunction:
This could be caused by excessive physical or emotional stress and extreme weight changes.
- Primary Ovarian Insufficiency (POI):
Also called premature menopause, this occurs when the ovaries stop working before age 40 due to genetics, autoimmune issues, or chemotherapy.
- Hyperprolactinemia:
Too much prolactin (often from a pituitary tumor) can interfere with the pulsatile release of gonadotropin-releasing hormone, causing anovulation.
- Structural blockage:
These issues prevent the egg from being released from the ovary or the embryo from implanting in the uterus. Structural causes of female infertility include;
- Fallopian tube blockage(Tubal factor):
This accounts for 15-20% of primary infertility and 40% of secondary infertility. It represents the aftermath of pelvic infection or surgery resulting in tissue damage, scarring, and adhesion formation.
This can affect tubal function and result in either partial or tubal occlusion. The functional competence of the fallopian tubes implies not just patency but also the integrity of the mucosa lining.
Any damage to the fallopian tubes tends to be irreversible; correction can be difficult.
Cause of fallopian tube blockage;
- Infection (Pelvic inflammatory disease): This is often caused by untreated sexually transmitted infections like chlamydia or gonorrhea.PID leads to inflammation and scar tissue that seals the tubes shut.
- Surgery: Tubal blockage could arise from the aftermath of pelvic/lower abdominal surgeries.
- Uterine structural issues:
If the uterus is misshapen or occupied by a growth, an embryo may not be able to implant, even if the sperm is able to get to the egg.
- Fibroids and polyps: These are noncancerous growths. If they grow into the uterine cavity or near the openings of the fallopian tubes, they act as physical barriers.
- Asherman Syndrome: Severe scarring inside the uterine cavity, often following surgery (like a D&C) or infection, which can cause the walls of the uterus to stick together.
- Congenital Abnormalities: Some women are born with an unusually shaped uterus, such as a septate uterus (a wall of tissue dividing the cavity) or a bicornuate uterus (heart-shaped).
- Cervical and Pelvic Adhesions:
- Cervical Stenosis: A narrowing or total blockage of the cervix, sometimes caused by past surgeries or trauma, which prevents sperm from entering the uterus.
- Pelvic Adhesions: Bands of scar tissue that form between pelvic organs (like the ovaries and the abdominal wall) after surgery, appendicitis, or infections. These can “trap” the ovaries so they can’t release eggs into the tubes.
3. Age-related egg quality and quantity: Women are born with a finite number of eggs that naturally decrease with age. Low quantity (Diminished Ovarian Reserve) means fewer chances to conceive each month and a shorter remaining fertile window.
As she ages, her eggs are more likely to have genetic abnormalities, leading to failure to conceive, implantation failure, or higher miscarriage rates.
By age 35, both quantity and quality begin to drop significantly, making it the leading cause of “unexplained” or age-related infertility.
Combined, Unexplained, and other factors in infertility:
Infertility isn’t always caused by a single, clear-cut issue in one person. When the standard causes (like blocked tubes or low sperm count) don’t tell the whole story, it often falls into one of these three complex categories.
1. Combined Factor Infertility
This occurs when both partners have one or more reproductive issues. For example, when a woman with PCOS has a partner with a varicocele (vein issues affecting sperm)
2. Unexplained Infertility
This is a “diagnosis of exclusion” given to 10-30% of couples after every standard test for infertility (HSG, semen analysis, and blood work) comes back completely normal. Science simply cannot yet see everything. This group has the highest rate of spontaneous (natural) pregnancy over time, though assisted reproductive techniques are often used to speed up the process.
3. Other Contributing Factors:
These are less common systemic or environmental issues that can interfere with conception:
- Immunological Factors: Sometimes a woman’s immune system mistakenly attacks sperm or a developing embryo (Antisperm antibodies or overactive Natural Killer cells).
- Cervical Factors: If the cervical mucus is too hostile (too thick or acidic), sperm cannot survive the journey into the uterus.
- Systemic Diseases: Uncontrolled diabetes, thyroid disorders, or Celiac disease can cause chronic inflammation that disrupts the reproductive cycle.
- Lifestyle & Environment: Long-term exposure to heavy metals, pesticides, or high-stress environments can cause “oxidative stress,” damaging both eggs and sperm at a cellular level.
Impact of Infertility on Marriage:
Infertility is a shared trauma that tests the very foundation of a marriage. It can either become the fire that forges a couple together or the wedge that drives them apart. Infertility has affected marriages in the following ways;
- The sex life of the couple;
One of the most immediate casualties of infertility is physical intimacy. When a couple is trying to conceive, sex often ceases to be an act of love and becomes a scheduled task. The time for intimacy becomes dictated by the ovulation calendar. For men, performance anxiety may occur. Intimacy may become like a chore for both couples. The women may start to feel as if they are merely a vessel. These strip away the pleasure and emotional bond that comes with sex.
- The weight of the diagnosis;
Even when a couple tries to be supportive, a medical diagnosis can create an unspoken dynamic. The identified partner with a medical condition would bear a crushing weight of guilt, feeling they are “depriving” their spouse of parenthood. It would take a lot of love, support, and care from the opposite partner for them to overcome this and for there to be no strain in the marriage.
- Financial strain:
Infertility is not just an emotional drain; it is a financial one. The cost of IVF, specialized drugs, or multiple surgeries can be overwhelming.
- Social impact :
Many couples pull away from social circles to avoid the pain of seeing pregnant friends or attending baby showers. It should be noted that amongst the partners, women are often unfairly perceived as the “source” of infertility, regardless of medical evidence. In patriarchal settings, infertility is frequently framed solely as a “female problem”.
Options of management:
Treatment typically follows a progressive “step-wise” clinical pathway, starting with the least invasive options.
- Ovulation Induction (OI):
The first line for many women with ovulatory disorders (like PCOS). Medications like Letrozole or Clomiphene stimulate the release of eggs.
- Intrauterine Insemination (IUI):
Healthy sperm are placed directly into the uterus during ovulation. It is a cost-effective, low-invasive option for mild male factor or unexplained infertility.
- Assisted Reproductive Technology (ART):
- IVF & ICSI:
In Vitro Fertilization (IVF) is the gold standard for success. In 2026, Intracytoplasmic Sperm Injection (ICSI) is frequently paired with AI-enhanced selection to treat severe male infertility.
- AI-Driven Care:
Artificial Intelligence is now used to analyze thousands of data points to predict the best embryos for transfer and to personalize hormonal medication dosages in real-time.
4. Surgical Interventions:
Minimally invasive robotic surgeries are used to repair blocked fallopian tubes, remove fibroids, or treat advanced endometriosis.
5. Essential Psychosocial support:
Because the emotional toll of infertility can actually impair treatment success, the WHO 2025 Global Guideline emphasizes that mental health care must be integrated into all ART protocols. This includes:
- Counseling
- Support groups
Modern care also recognizes that a body under chronic stress has sub-optimal outcomes. Thus nutritional support and lifestyle modifications are advised.
6. Third-Party Options & Fertility Preservation
When a couple’s own gametes are not viable, or for single/same-sex parents:
- Donor Gametes & Surrogacy: Using donor eggs or sperm, or a gestational carrier, remains a highly successful path to parenthood.
- Fertility Preservation: Oocyte and sperm cryopreservation (freezing) is now standardized with ultra-rapid vitrification, offering a “biological insurance” for those not ready to conceive immediately.
CONCLUSION:
Infertility is a medical challenge, but it is also a deeply emotional journey for many families. While the causes are complex and the treatments can be difficult, modern medicine and stronger support systems offer more hope than ever before. By talking openly about these struggles, we can break the silence and ensure that no one has to face the path to parenthood alone.
