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Houston Fertility Journal

    Understanding What Might Be Causing Your Infertility

    February 22, 2019 / by Center of Reproductive Medicine   

    Center of Reproductive Medicine


    It’s a scene that plays out in thousands of homes every month -- a ritual, of sorts: the home pregnancy test. For couples with infertility, the absence of two lines can come to feel like a sign of personal failure. Month after month, frustration can turn to exhaustion, depression, and deep sadness. Infertility can be deeply isolating, but you are not alone.

    The good news is that infertility is a treatable medical condition. Most infertile couples are able to have a child with the right treatment. But age also affects fertility. That means that the longer you wait to get help, the more your chances of a successful pregnancy decrease. Here is what you need to know about the most common causes of infertility.

    Causes of Infertility

    Virtually all cases of infertility boil down to one of a few issues:

    • A problem with the eggs. To get pregnant, a woman must produce reasonably healthy eggs. If a woman does not ovulate, she will not get pregnant. Women who ovulate irregularly or infrequently are less likely to get pregnant. Moreover, as a woman ages, the quality of her eggs tends to decline. As a result, it may take longer to get pregnant. It can also lead to miscarriages and birth defects.
    • A problem with the sperm. To impregnate a woman, the sperm must be able to travel to the egg. This requires having a strong sperm count and sperm that are healthy with good motility to swim to the egg. If the sperm are malformed or carry mutations, they may not be able to fertilize the egg -- or they may result in a pregnancy that ends in miscarriage.
    • Sexual Disfunction. To produce a child, a couple must be able to have intercourse that ends in ejaculation. Men with erectile dysfunction or ejaculation issues may need help to impregnate a partner.
    • Implantation issues. Implantation is when the egg implants in the uterine wall, triggering physical and hormonal changes that officially begin a pregnancy. Not all fertilized eggs are able to implant in the uterus. Sometimes a blockage in the fallopian tubes prevents this.
    • Hormonal problems. Hormones help orchestrate every aspect of pregnancy for both men and women. They play an especially important role in early pregnancy. If a woman’s body does not produce enough progesterone or hCG, she may have an early miscarriage.
    • Genetic issues. If a fertilized egg carries certain genetic mutations, the body may not allow the pregnancy to continue. This can cause implantation to fail, or result in an early miscarriage.

    Conditions That Can Cause Infertility

    Dozens of medical conditions, including those that don’t directly affect the reproductive system, can cause infertility. For example, some studies show higher rates of infertility among people with rheumatoid arthritis. Chronic respiratory infections may also affect fertility. The most common causes of infertility, however, affect hormones, sperm quality, and ovulation.

    These are the conditions your doctor will likely test for first:


    Endometriosis is a condition that causes endometrial tissue, which lines the uterus, to travel outside of the uterine walls. Endometriosis can cause infertility in several ways. It may damage the fallopian tubes, making it difficult to ovulate or for the egg to travel to the uterus. It can also make it difficult for fertilized eggs to implant in the uterus. Some forms of endometriosis can also cause early miscarriages -- often before you even know you’re pregnant. Some women with endometriosis experience intense stomach or pelvic pain. This can make sex painful, further undermining their chances of getting pregnant.


    Endometriosis is a leading cause of infertility.

    Polycystic Ovary Syndrome (PCOS)

    PCOS is a complex hormone disorder that can cause weight gain, excess body hair, and irregular menstrual cycles. Women with PCOS tend not to ovulate as frequently as other women. This can reduce the chances of a successful pregnancy. PCOS also affects hormone levels. This can make it difficult for the body to sustain a healthy pregnancy. Some women with PCOS also become insulin resistant or diabetic.


    A varicocele is a swollen vein in the testicles. In some men, it makes it difficult for the sperm to travel from the testicles to the penis. As a result, even though the man produces normal sperm, his sperm count is reduced. Varicocele is a leading cause of infertility in men, but not all men with varicocele are infertile.

    Sperm Issues

    Issues with sperm -- including low sperm count, low sperm motility, and poor sperm morphology--are major causes of male infertility. In serious cases, a man may produce no healthy sperm at all. Even when a man produces healthy sperm, his chances of impregnating a partner are significantly reduced if the woman also has a fertility issue. Even minor sperm issues can make pregnancy more difficult to achieve.


    Various infections can change virtually everything about how the body works. They can damage sperm and eggs, making pregnancy more difficult. They can cause chronic inflammation, making it more difficult for the woman’s body to produce an egg, or for the egg to implant in the uterus. They can damage structures in the body, affecting implantation and potentially causing miscarriages. Sexually transmitted infections can cause a condition called pelvic inflammatory disease that damages the reproductive organs. Men, too, may be less fertile following an untreated STI/STD.

    Sexually transmitted diseases aren’t the only infections that can affect fertility. Chronic, untreated illnesses such as rheumatoid arthritis, diabetes, and other diseases can also play a role in infertility.

    Structural Abnormalities

    Some men have structural problems with their reproductive systems that cause damage to their sperm. In other cases, a man might have retrograde ejaculation. This means he ejaculates back into his body instead of his partner.

    Structural issues in women can also affect fertility. Damage to the fallopian tubes, often due to STDs, may make it difficult for the egg to travel to the uterus. Endometriosis may damage the uterus and surrounding organs.

    The extent to which structural abnormalities affect fertility varies. Sometimes these issues only decrease fertility, not destroy it. In other cases, such as the inability to ejaculate into a partner, a pregnancy becomes impossible without help.

    Sexual Dysfunction

    Men with erectile dysfunction or ejaculation issues may need help to impregnate a partner. Sometimes psychological concerns make sex psychologically difficult. For example, if one partner has a history of sexual trauma, having sex frequently enough to cause a pregnancy can be difficult. Infertility may compound this trauma, making sexual issues even worse.

    Lifestyle and Health Issues

    Various unhealthy lifestyle habits and health issues can lower fertility. If you have several unhealthy habits, your fertility may be very low.

    The good news is that you can fix these issues:

    • Being too thin, especially if you are female. Women who are too thin may not ovulate regularly or may produce lower quality eggs.
    • Being overweight. This can affect hormones and overall health.
    • Smoking, excessive drinking, or drug use.
    • Exposure to poisonous substances that mutate sperm or eggs, or that cause birth defects.
    • Taking certain medications.

    Be sure to ask your fertility specialist about health habits that can promote fertility, especially when you begin infertility treatment.

    Bad Timing

    To maximize the chances of pregnancy, it’s important to have sex just before a woman ovulates. Most couples will be able to do this just by having frequent sex. But couples who don’t know how to predict ovulation or who have infrequent sex may reduce their chances. If there is an underlying condition that decreases fertility, simply timing intercourse for the most fertile time of the month can greatly increase the likelihood of a successful pregnancy.

    Female Infertility Symptoms

    Not all women with infertility have symptoms. Women who experience the following, however, may want to see a provider before trying for a pregnancy:

    • Infrequent or irregular periods
    • Very heavy or painful periods
    • Pain during sexual intercourse
    • Lots of blood clots in menstrual blood
    • Unexplained weight gain
    • Excessive body hair, especially on the face
    • Insulin resistance
    • A history of STDs
    • Being very underweight or very overweight
    • Not menstruating

    Male Infertility Symptoms


    Most infertile men do not have any symptoms at all. In fact, if the problem is only with the man’s sperm, he’s unlikely to have symptoms. The absence of symptoms does not mean a man is fertile. 

    Some symptoms a man might experience include:

    • Swelling or pain in the testicles or penis
    • Blood in the semen
    • Pain during urination or ejaculation
    • Difficulty getting an erection
    • Difficulty having an orgasm
    • Being very overweight
    • A history of STDs
    • A history of prostate problems

    Diagnosing and Treating Infertility

    To diagnose and treat infertility, an infertility specialist will take a complete medical history and ask questions about how long you have been trying and what you have tried. Based on this information, they will determine which tests are appropriate.

    The most common tests include:

    • Semen analysis to check the man’s sperm count and quality.
    • Blood tests to assess hormone levels.
    • A physical exam of both the man and woman to look for physical abnormalities.
    • Monthly cycle tracking to provide details about how often a woman is ovulating.
    • Analysis of the woman’s cervical and vaginal mucus. Sometimes a doctor wants to assess this fluid immediately after a woman has sex to see how it interacts with the man’s sperm.
    • Imaging scans to look at the internal reproductive organs.
    • STD testing.
    • A general health screening to assess for undiagnosed conditions that might affect fertility.

    Once a doctor arrives at a diagnosis, they can recommend a customized treatment plan. Some options include:

    • Using medications to help a woman ovulate more frequently.
    • A procedure to clear blockages in the woman’s fallopian tubes.
    • Surgery to treat and remove varicoceles.
    • Education about proper intercourse timing. A doctor may also recommend the use of ovulation predictor kits, cycle tracking, and basal body temperature testing.
    • Medication to treat infections.
    • Hormone treatments to address hormonal imbalances.
    • Lifestyle changes such as weight loss.
    • Artificial reproductive technologies such as in vitro fertilization (IVF) and intrauterine insemination (IUI).
    • The use of donor sperm or eggs.

    If a doctor cannot diagnose the cause of infertility, they may still recommend drugs to encourage ovulation or artificial reproductive technologies. In cases of unexplained infertility, cycle tracking can be helpful, as can diligent timing of sexual intercourse.

    When to Seek Help From a Fertility Specialist


    Couples with risk factors for infertility or a history of infertility should seek treatment right away. See a fertility specialist if:

    • The woman is under 35 and the man is under 40 and you have tried for longer than a year.
    • The woman is over 35 or the man is over 40 and you have tried for longer than 6 months.
    • The woman has very irregular menstrual cycles.
    • The woman has had two or more miscarriages in a row.

    Seeking help does not mean you’re giving up. An infertility specialist really can help, even if you’ve been trying for years. At the Center of Reproductive Medicine, we specialize in helping couples manage infertility. We know this is a complex challenge that can affect your relationship, your future, and even your sense of self. We treat you with sensitivity, warmth, and compassion, and view you as a whole person -- not just an infertility case. We can also connect you to support groups, community resources, and other experts who can help you navigate the challenges of infertility. You are not alone. This is not hopeless.

    It’s not your fault. Things can get better. We’ll work with you to show you how. So don’t delay. 

    The Infertility Journey: Your Questions from A to Z

    Topics: Fertility Specialist, Infertility Treatment, Signs of Infertility

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