Infertility happens when a couple cannot conceive after having regular unprotected sex.
It may be that one partner cannot contribute to conception, or that a woman is unable to carry a pregnancy to full term. It is often defined as not conceiving after 12 months of regular sexual intercourse without the use of birth control.
In India, around 10 percent of women aged 15 to 44 years are estimated to have difficulty conceiving or staying pregnant. Worldwide, 8 to 12 percent of couples experience fertility problems. Between 45 and 50 percent of cases are thought to stem from factors that affect the man.
Treatment is often available.
Causes in men
The following are common causes of infertility in men.
Semen and sperm
Semen is the milky fluid that a man’s penis releases during orgasm. Semen consists of fluid and sperm. The fluid comes from the prostate gland, the seminal vesicle, and other sex glands.
The sperm is produced in the testicles.
When a man ejaculates and releases semen through the penis, the seminal fluid, or semen, helps transport the sperm toward the egg.
The following problems are possible:
- Low sperm count: The man ejaculates a low number of sperm. A sperm count of under 15 million is considered low. Around one-third of couples have difficulty conceiving due to a low sperm count.
- Low sperm mobility (motility): The sperm cannot “swim” as well as they should to reach the egg.
- Abnormal sperm: The sperm may have an unusual shape, making it harder to move and fertilize an egg.
If the sperm do not have the right shape, or they cannot travel rapidly and accurately towards the egg, conception may be difficult. Up to 2 percent of men are thought to have suboptimal sperm.
Abnormal semen may not be able to carry the sperm effectively.
This can result from:
- A medical condition: This could be a testicular infection, cancer, or surgery.
- Overheated testicles: Causes include an undescended testicle, a varicocele, or varicose vein in the scrotum, the use of saunas or hot tubs, wearing tight clothes, and working in hot environments.
- Ejaculation disorders: If the ejaculatory ducts are blocked, semen may be ejaculated into the bladder
- Hormonal imbalance: Hypogonadism, for example, can lead to a testosterone deficiency.
Other causes may include:
- Genetic factors: A man should have an X and Y chromosome. If he has two X chromosomes and one Y chromosome, as in Klinefelter’s syndrome, the testicles will develop abnormally and there will be low testosterone and a low sperm count or no sperm.
- Mumps: If this occurs after puberty, inflammation of the testicles may affect sperm production.
- Hypospadias: The urethral opening is under the penis, instead of its tip. This abnormality is usually surgically corrected in infancy. If the correction is not done, it may be harder for the sperm to get to the female’s cervix. Hypospadias affects about 1 in every 500 newborn boys.
- Cystic fibrosis: This is a chronic disease that results in the creation of a sticky mucus. This mucus mainly affects the lungs, but males may also have a missing or obstructed vas deferens. The vas deferens carries sperm from the epididymis to the ejaculatory duct and the urethra.
- Radiation therapy: This can impair sperm production. The severity usually depends on how near to the testicles the radiation was aimed.
- Some diseases: Conditions that are sometimes linked to lower fertility in males are anemia, Cushing’s syndrome, diabetes, and thyroid disease.
Some medications increase the risk of fertility problems in men.
- Sulfasalazine: This anti-inflammatory drug can significantly lower a man’s sperm count. It is often prescribed for Crohn’s disease or rheumatoid arthritis. Sperm count often returns to normal after stopping the medication.
- Anabolic steroids: Popular with bodybuilders and athletes, long-term use can seriously reduce sperm count and mobility.
- Chemotherapy: Some types may significantly reduce sperm count.
- Illegal drugs: Consumption of marijuana and cocaine can lower the sperm count.
- Age: Male fertility starts to fall after 40 years.
- Exposure to chemicals: Pesticides, for example, may increase the risk.
- Excess alcohol consumption: This may lower male fertility. Moderate alcohol consumption has not been shown to lower fertility in most men, but it may affect those who already have a low sperm count.
- Overweight or obesity: This may reduce the chance of conceiving.
- Mental stress: Stress can be a factor, especially if it leads to reduced sexual activity.
Laboratory studies have suggested that long-term acetaminophen use during pregnancy may affect fertility in males by lowering testosterone production. Women are advised not to use the drug for more than one day.
Causes in women
Infertility in women can also have a range of causes.
Risk factors that increase the risk include:
- Age: The ability to conceive starts to fall around the age of 32 years.
- Smoking: Smoking significantly increases the risk of infertility in both men and women, and it may undermine the effects of fertility treatment. Smoking during pregnancy increases the chance of pregnancy loss. Passive smoking has also been linked to lower fertility.
- Alcohol: Any amount of alcohol consumption can affect the chances of conceiving.
- Being obese or overweight: This can increase the risk of infertility in women as well as men.
- Eating disorders: If an eating disorder leads to serious weight loss, fertility problems may arise.
- Diet: A lack of folic acid, iron, zinc, and vitamin B-12 can affect fertility. Women who are at risk, including those on a vegan diet, should ask the doctor about supplements.
- Exercise: Both too much and too little exercise can lead to fertility problems.
- Sexually transmitted infections (STIs): Chlamydia can damage the fallopian tubes in a woman and cause inflammation in a man’s scrotum. Some other STIs may also cause infertility.
- Exposure to some chemicals: Some pesticides, herbicides, metals, such as lead, and solvents have been linked to fertility problems in both men and women. A mouse study has suggested that ingredients in some household detergents may reduce fertility.
- Mental stress: This may affect female ovulation and male sperm production and can lead to reduced sexual activity.
Treatment will depend on many factors, including the age of the person who wishes to conceive, how long infertility has lasted, personal preferences, and their general state of health.
Frequency of intercourse
The couple may be advised to have sexual intercourse more often around the time of ovulation. Sperm can survive inside the female for up to 5 days, while an egg can be fertilized for up to 1 day after ovulation. In theory, it is possible to conceive on any of these 6 days that occur before and during ovulation.
However, a survey has suggested that the 3 days most likely to offer a fertile window are the 2 days before ovulation plus the 1 day of ovulation.
Some suggest that the number of times a couple has intercourse should be reduced to increase sperm supply, but this is unlikely to make a difference.
Fertility treatments for men
Treatment will depend on the underlying cause of infertility.
- Erectile dysfunction or premature ejaculation: Medication, behavioral approaches, or both may help improve fertility.
- Varicocele: Surgically removing a varicose vein in the scrotum may help.
- Blockage of the ejaculatory duct: Sperm can be extracted directly from the testicles and injected into an egg in the laboratory.
- Retrograde ejaculation: Sperm can be taken directly from the bladder and injected into an egg in the laboratory.
- Surgery for epididymal blockage: A blocked epididymis can be surgically repaired. The epididymis is a coil-like structure in the testicles which helps store and transport sperm. If the epididymis is blocked, sperm may not be ejaculated properly.
Fertility treatments for women
Fertility drugs might be prescribed to regulate or induce ovulation.
- Clomifene (Clomid, Serophene): This encourages ovulation in those who ovulate either irregularly or not at all, because of PCOS or another disorder. It makes the pituitary gland release more follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
- Metformin (Glucophage): If Clomifene is not effective, metformin may help women with PCOS, especially when linked to insulin resistance.
- Human menopausal gonadotropin, or hMG (Repronex): This contains both FSH and LH. Patients who do not ovulate because of a fault in the pituitary gland may receive this drug as an injection.
- Follicle-stimulating hormone (Gonal-F, Bravelle): This hormone is produced by the pituitary gland that controls estrogen production by the ovaries. It stimulates the ovaries to mature egg follicles.
- Human chorionic gonadotropin (Ovidrel, Pregnyl): Used together with clomiphene, hMG, and FSH, this can stimulate the follicle to ovulate.
- Gonadotropin-releasing hormone (Gn-RH) analogs: These can help women who ovulate too early-before the lead follicle is mature-during hmG treatment. It delivers a constant supply of Gn-RH to the pituitary gland, which alters the production of hormone, allowing the doctor to induce follicle growth with FSH.
- Bromocriptine (Parlodel): This drug inhibits prolactin production. Prolactin stimulates milk production during breastfeeding. Outside pregnancy and lactation, women with high levels of prolactin may have irregular ovulation cycles and fertility problems.