Causes of Infertility
Infertility is generally defined as not being able to conceive after one year of trying, or six months for women over 35. It’s a common, medically recognized condition, and identifying the underlying cause is the first step toward a treatment plan that works for you. There are many causes of infertility in both men and women. Establishing a diagnosis is the first step towards developing a treatment plan and helping you grow your family.
Causes of Female Infertility
Studies show that up to 40% of cases of couples struggling to conceive are related to female infertility, which can be caused by a variety of conditions or health factors. Common reasons for female infertility include:
Ovulation and Ovulation Disorders
Roughly 25% of women with infertility have issues with ovulation. There are many reasons why a person may not ovulate regularly, many of which are treatable through lifestyle changes or fertility treatment. Ovulation disorders are also closely tied to hormone regulation elsewhere in the body. Conditions like hyperthyroidism and hypothyroidism can throw off the hormonal signals needed for regular ovulation, making conception more difficult.
Blocked Fallopian Tubes
The fallopian tubes carry an egg from the ovary to the uterus and are also where fertilization typically takes place. When one or both tubes are blocked, often due to scar tissue, endometriosis, or a past pelvic infection, sperm and egg may never meet, or a fertilized egg may not be able to reach the uterus. Blocked tubes are one of the more straightforward causes of infertility to diagnose through imaging, and treatment ranges from surgery to in vitro fertilization IVF, which bypasses the tubes altogether.
Age
A woman’s fertility starts to decline gradually after age 30, and more dramatically as she gets into her late 30s. As a woman ages, the chance of genetic mutations and/or fetal abnormalities also increases. Treatment may include testing each embryo to determine whether all of its chromosomes are normal.
PMOS or PCOS
Polyendocrine metabolic ovarian syndrome (PMOS), formerly known as polycystic ovarian syndrome (PCOS) affects approximately 10% of women in their childbearing years. Treatment for PMOS may include medication, lifestyle changes like diet and exercise, and/or IVF.
Endometriosis
Approximately 35 to 50% of women with infertility also have endometriosis. Treatment may include surgery or IVF. Endometriosis occurs when tissue similar to the uterine lining grows outside of it, often on the ovaries, fallopian tubes, or surrounding pelvic structures. This misplaced tissue can cause inflammation, scarring, and structural changes that make conceiving more difficult.
Adenomyosis
This condition occurs when endometrial tissue, which lines the uterus, grows into the outer muscular tissue, causing structural issues. Treatment includes medication and (less frequently) surgery.
Cervical Disorders
Cervical disorders can prevent the sperm from being able to enter the uterus. Treatment may include Intrauterine Insemination (IUI) or IVF.
Blood-Clotting Disorders
Excessive clotting is associated with recurrent miscarriage as well as slow fetal growth and high blood pressure. Treatment frequently includes blood-thinning medication.
Cancer
The disease itself, along with treatments such as chemotherapy and radiation, can greatly diminish or damage sperm and eggs. To prevent this, many patients freeze their eggs or sperm or embryos for future use prior to receiving cancer treatment.
Lifestyle
Everyone’s fertility is affected to some degree by lifestyle. Being overweight, smoking, drinking alcohol, being sedentary, and even exposure to some plastics can all decrease fertility. Treatment includes proper diet, weight loss, moderate exercise, and avoiding harmful substances. Extreme physical or chronic stress, very low body fat, and rapid weight loss or gain can all disrupt the hormonal signals that regulate ovulation. The body reads these shifts as a sign that conditions aren’t right for pregnancy and may pause or interrupt the cycle as a result. Even modest movement toward a stable weight and lower stress can help restore more regular cycles.
Primary Ovarian Insufficiency (POI)
Primary ovarian insufficiency occurs when the ovaries stop functioning normally before age 40, leading to a reduced egg supply and irregular or absent periods. Unlike menopause, POI doesn’t always mean periods stop completely or that pregnancy is impossible, but it typically makes conceiving more difficult. Because POI affects ovulation directly, it’s also worth a mention in the ovulation and ovulation disorders section above.
Uterine Fibroids or Polyps
Fibroids and polyps are noncancerous growths that can develop in or around the uterus. Depending on their size and location, they can distort the shape of the uterine cavity, block the fallopian tubes, or interfere with embryo implantation. Many patients with fibroids or polyps still conceive successfully, particularly once the growths are addressed.
Pelvic Inflammatory Disease (PID)
Pelvic inflammatory disease is an infection of the reproductive organs, often resulting from an untreated sexually transmitted infection. Left untreated, PID can cause scarring in the fallopian tubes and surrounding structures, increasing the risk of blocked tubes and infertility. Early treatment of the underlying infection significantly reduces this risk.
Recurrent Pregnancy Loss
We offer specialized assistance to those faced with the heartache of recurrent pregnancy loss (RPL). Defined as having two or more miscarriages, recurrent pregnancy loss can be caused by many things, with the risk going up with age. We have established our Center for Recurrent Pregnancy Loss because we recognize the emotional toll that those with RPL endure. We offer counseling, compassionate care, and extensive expertise to those who suffer from repeated miscarriages in order to maximize the chances of starting a family.
Causes of Male Infertility
Infertility does not affect only women — millions of men suffer as well. In fact, new studies show that in approximately 40 percent of couples dealing with infertility, the male partner is either the sole cause or a contributing cause of infertility. Difficulties range from issues with sperm production, such as azoospermia (no sperm cells are produced) or oligospermia (few sperm cells are produced), to obstruction of sperm delivery.
Sperm Production Disorder
Often, male infertility is the result of abnormal sperm production. This can affect the number of sperm, the sperm’s ability to swim, or the shape of the sperm. All of these have the potential to affect the sperm’s ability to find and fertilize the egg. There are many causes of abnormal sperm production, many of which are treatable.
Obstructive Problems
Sometimes, sperm cells are blocked. This can be a blockage where sperm joins the other fluids in the ejaculate, so fluid is still produced with orgasm but doesn’t contain sperm; other times, no fluid comes out at all. Obstruction can be caused by a number of reasons and is often treatable.
Genetic Diseases and Conditions
In rare cases, infertility in men is caused by a genetic disease, such as cystic fibrosis, or a chromosomal abnormality.
Varicocele
Varicocele is an enlargement of the veins within the scrotum, similar to a varicose vein. It can raise the temperature around the testicles, which may reduce sperm production and quality. Varicoceles are a common and often treatable cause of male infertility, and they’re the most common cause of secondary infertility in men — when a man has fathered a child in the past but struggles to do so again.
Infections
Certain infections, including sexually transmitted infections, epididymitis, or mumps orchitis, can damage sperm production or block the pathways sperm travel through. Some infections cause lasting scarring even after treatment, while others resolve without ongoing effects on fertility. Testing for infection is often one of the first steps in evaluating male infertility.
Hormones
Sperm production depends on a delicate balance of hormones, including testosterone and signals from the pituitary gland. Low testosterone or pituitary gland issues can reduce sperm count or quality, even when the testicles themselves are functioning normally. Hormone testing can help identify whether this is a contributing factor. Taking testosterone is not a fertility-safe way to treat low testosterone. Testosterone replacement therapy (TRT) shuts down the testicles’ natural function and often causes sperm counts to drop to zero.
Lifestyle
Chronic stress, drug use, excessive alcohol consumption, and obesity can all affect sperm production and quality in men. These factors tend to be more manageable than other causes of male infertility and addressing them can meaningfully improve outcomes. A fertility specialist can help identify which changes are most likely to make a difference.
Other Causes of Infertility
- Primary infertility is the inability to become pregnant, or to carry a pregnancy to term, despite one year of regular unprotected intercourse (six months for women over 35), in someone who has never had a prior pregnancy or live birth.
- Secondary Infertility is the inability to become pregnant — despite engaging in regular unprotected intercourse — following the birth of one or more biological children who were born without the aid of fertility treatment or medications.
- Unexplained infertility is the failure to determine a cause of infertility after a thorough evaluation of both the male and female partners. Approximately 10 percent of infertility is unexplained.
