Common causes of infertility in men and women

If you’re struggling to have a baby, you’re not alone. Many couples battle to conceive, especially in the first year of trying.

 Infertility is a condition where you cannot get pregnant after one year of trying to conceive.

It’s not always easy to get pregnant. We explain what variables can influence your chances of conceiving and discuss common reasons for female and male infertility.

What is infertility?

Infertility, a medical disorder characterised by the inability to conceive a child, affects one out of every eight couples. Experts define infertility as a couple actively attempting to conceive for at least a year without success. Those who have recurring miscarriages may be diagnosed with infertility.

Contrary to popular belief, infertility is not primarily a female issue. According to research, about 40% of cases are tied to women, whereas 40% are related to men. The other 20% of the time, it’s a combination of both couples’ ailments or unknown factors.

It helps to understand that childbirth is a complex process involving four critical steps:

  1. A woman has to produce eggs, and a man has to produce sperm.
  2. A woman has to have healthy fallopian tubes that allow sperm to reach the egg readily.
  3. A man’s sperm has to have the ability to fertilise the egg once it reaches it.
  4. A fertilised egg has to have the capacity to adhere to the uterus and develop normally.

When one or more of these stages fails, infertility can occur.

What causes female infertility?

Because conception is so intricate, a variety of circumstances can contribute to female infertility. Here are a few of the most common.

Age of the mother

Maternal age has the greatest impact on your ability to conceive. This is because women are born with all of their eggs, and the amount (and quality) of eggs declines over time. Between the ages of 35 and 40, two-thirds of one’s fertility potential is lost.

Damage to the fallopian tube

Fallopian tube disease accounts for approximately 20% of all infertility cases treated. Sperm may struggle to reach the egg if the fallopian tubes are damaged or obstructed. A fertilised egg may also have difficulty making its way to the uterus and developing into a baby.

Fallopian tube damage can be caused by a variety of factors, including pelvic inflammatory disease (an infection caused by untreated sexually transmitted infections such as chlamydia and gonorrhoea), endometriosis, or a previous ectopic pregnancy (where the fertilised egg implants outside of the uterus). A history of pelvic pain or very painful periods are common symptoms of fallopian tube injury.


Endometriosis is a condition in which uterine lining tissue grows outside the uterus, most commonly on the ovaries, fallopian tubes, bladder, and/or colon. Endometriosis can cause little pain in some women, and the diagnosis can only be diagnosed through an outpatient surgical procedure called a laparoscopy.

Endometriosis can cause a buildup of scar tissue between the uterus, ovaries, and fallopian tubes, which can impede egg transport to the fallopian tubes. It can also induce endometrial cysts, which form inside the ovaries and hinder the egg from being released or collected by the fallopian tube. Furthermore, endometriosis might make the fertilised egg difficult to adhere to the uterine wall.

Ovulation issues

If you don’t ovulate normally, you don’t produce healthy eggs for sperm to fertilise. Hormonal abnormalities are frequently the cause of ovulation issues. The most common signs of ovulation problems are irregular or missed periods.

Polycystic Ovarian Syndrome

Polycystic ovarian syndrome (PCOS) affects up to 10% of all women. The illness produces a hormonal imbalance, causing the body to produce too much testosterone, and it can also interfere with ovulation. In addition to irregular or missing periods, women with PCOS may be overweight, have excess body or facial hair, and have acne.

Uterus issues

If an egg is unable to adhere normally to the uterine wall, it cannot grow into a healthy child. Fibroids and polyps, which are benign tissue growths from the uterine wall that can influence fertility depending on their size and location, can cause uterine difficulties. Scar tissue in the uterus caused by infection, miscarriage, or abortion could also be a factor. Lower abdomen pain or bloating that is unexplained may be a sign of uterine abnormalities that might impact fertility.

Being obese or underweight

Women with BMIs less than 20 or greater than 27 are less likely to conceive than women with BMIs within that range. The primary cause is: Weighing too little (due to extreme exercise or not eating enough) or too much can put your hormones out of whack and disrupt ovulation.

Sexually Transmitted Diseases (STDs)

STDs such as chlamydia and gonorrhoea (both of which are easily treated with medication) can cause pelvic infections that interfere with pregnancy.

Autoimmune conditions

Lupus, diabetes, thyroid disease, and rheumatoid arthritis are all conditions that can interfere with conception.

Certain medications

Antidepressants, antibiotics, pain relievers, and other medications used to treat chronic diseases may cause infertility.

Tobacco or alcohol use

Cigarette smoking has been proven in studies to interfere with ovulation and damage eggs, making them more susceptible to genetic abnormalities that can lead to miscarriage. Furthermore, while the odd cocktail has not been found to be harmful, heavy drinking has been connected to female infertility.

Environmental dangers

Long-term exposure to high levels of mental stress, high temperatures, toxins, radiation, or high levels of electromagnetic or microwave emissions may diminish a woman’s fertility.

Other causes of female infertility

Uterine fibroids, immune system illnesses, kidney disease and diabetes, premature menopause, and cancer and its treatment are some of the remaining causes of infertility in women (like chemotherapy and radiation).

What causes male infertility?

Male infertility is usually caused by a problem creating healthy sperm or a flaw in the sperm’s ability to reach and fertilise an egg.

It only takes one sperm to fertilise one egg, but the chances of any one sperm cell reaching and entering an egg are extremely tiny. The more sperm produced after ejaculation (a sperm count) you have, the greater your chances of conceiving. Men with sperm counts of 10 million or less per millilitre of sperm may have more fertility issues than men with normal sperm counts (20 million or more sperm per millilitre of semen). It is important to note that oligospermia refers to a low sperm count, whereas azoospermia refers to a lack of sperm production.

Problems with sperm count can also be caused by varicocele, which is a varicose vein in the testicle that keeps the temperature too high to generate sperm correctly. Sperm with aberrant structures may struggle to make the long journey from the vagina to the fallopian tube, and they may have difficulty entering the egg once they reach it.

Managing male infertility

Problems with sperm motility may be caused by hormonal imbalances, defects in the testicles, exposure to certain environmental pollutants or chemicals, certain drugs (such as steroids), hereditary disorders, infections such as chlamydia and gonorrhoea, or cancer.

Problems with sperm production

Although it may seem simple, sperm must exit the penis in order to reach the egg- and male infertility might occur from difficulties or blockages that prevent this from happening. Sexual issues (such as premature ejaculation or difficulty sustaining an erection), retrograde ejaculation (when sperm flows into the bladder rather than out through the penis), and obstructions in the testicles or sperm tubes are all possible causes.

Certain factors increase the likelihood of sperm production issues. Diabetes, bladder problems, and prostate problems, for example, can all impair retrograde ejaculation. Men with cystic fibrosis frequently have vas deferens difficulties, which is the tube that transfers sperm from the testicles to the penis.

Using tobacco and alcohol

According to research, cigarettes and tobacco have a deleterious impact on male fertility, most likely via lowering sperm quality. Moderate alcohol use is unlikely to have an effect on fertility, but ingesting enough alcohol to injure the liver or other organs can make men less fertile by reducing testosterone, shrinking the testicles, making it difficult to get an erection, and slowing sperm motility.

Certain medications and drugs

Marijuana and cocaine use have been proven to reduce sperm quality and quantity. Similarly, certain medicines (such as steroids) may have an effect on sperm quality.

Chronic exposure to lead, cadmium, mercury, hydrocarbons, pesticides, radiation, and X-rays may reduce sperm count and quality.


Significant weight gain can disrupt hormones that affect male fertility. According to one study, being overweight can raise male infertility by 10%.

Heat exposure

The use of saunas, steam rooms, hot tubs, whirlpools, and hot baths on a regular basis may temporarily affect sperm production and count.

Other medical issues

Men who have a history of prostatitis or genital infection, mumps after puberty, hernia surgery, undescended testicles, or scrotal varicose veins (varicocele) may also have a drop in fertility.

Sexually Transmitted Diseases (STDs)

STDs such as chlamydia and gonorrhoea can induce scarring in the testicles, preventing sperm from forming.

When should you see a doctor about infertility?

Remember that if you’re still receiving a negative pregnancy test result after a few months of trying, you may simply need more time. In any given month, your chances of having a baby are actually quite slim (especially if you are not tracking your ovulation), and it can take months for fertile couples to conceive naturally.

In general, however, experts recommend you see a doctor if you have been trying to get pregnant for more than a year without success.