Causes of infertility

What is infertility
Infertility is when pregnancy does not happen after a year of regular, unprotected sex for most couples.
It’s a tough and emotional experience that affects millions of people worldwide. Sometimes it is caused by male factors, like low sperm count or sperm not moving properly, or female factors, like blocked fallopian tubes or problems with ovulation.
Other times, doctors cannot find a clear cause (unexplained infertility). The good news is there are many treatments available, and lots of people facing infertility go on to have healthy pregnancies and children of their own.
Signs and symptoms of infertility
The most common sign is simply not getting pregnant, and there may be no other obvious symptoms.
For some women, irregular periods or the absence of periods could indicate an issue, while some men may notice changes linked to hormonal problems, like hair growth or sexual function.
The good news is that many couples eventually conceive, whether naturally or with the help of treatment. If you are concerned, reaching out to a doctor can help you take the next steps.
When should I see a doctor about infertility
Most couples do not need to see a doctor about infertility unless they have been trying to get pregnant for at least one year. However, it might be a good idea to get medical advice if:
For women:
- You are 35 or older and have been trying for six months or more.
- You are over 40.
- You have irregular, very painful, or no periods at all.
- You have known fertility issues, endometriosis, or a history of pelvic inflammatory disease.
- You have had more than one miscarriage.
- You have received cancer treatments like chemotherapy or radiation.
For men:
- You have a history of testicular, prostate, or sexual health problems.
- You have had cancer treatment such as chemotherapy.
- You have had hernia surgery.
- You notice smaller-than-usual testicles or swollen veins in the scrotum.
- You have experienced infertility with a partner before.
- There is a history of infertility in your family.
Why am I infertile
Infertility affects so many people, but when you are the one facing it, it can feel deeply personal and isolating. It is natural to ask yourself, “Why me?”
If you are struggling to get pregnant or have experienced multiple miscarriages, it is easy to blame yourself. But the truth is, humans are not naturally very good at reproducing, and infertility is not anyone’s fault. The causes are often evenly split between men and women. Infertility is a shared experience, and understanding the potential reasons behind it can be a big step in managing it.
Causes of female infertility
There are many reasons why a woman might face infertility, but these usually fall into a few key categories. Understanding the possible causes can help your doctor develop a treatment plan that works best for you.
Infertility and age: Understanding ovarian reserve
Dr. Guimarães, medical director of Procriar, explains that age is one of the most common factors in female infertility:
“Unlike men, who keep producing sperm throughout their lives, women are born with all the eggs they will ever have. Over time, the number of eggs—called the ovarian reserve—naturally decreases. This decline becomes more noticeable after the age of 35.”
As ovarian reserve diminishes, the quality of the eggs also tends to decline, making it harder to conceive. That said, many women in their late 30s and 40s still go on to have children, though it may take longer and involve more challenges, such as a higher risk of miscarriage.
Infertility and ovulation disorders
Problems with ovulation are another common reason why some women struggle to conceive.
Ovulation is the process where the ovary releases an egg, ready to meet sperm for fertilisation. If ovulation is irregular or does not happen at all, it can make getting pregnant much harder.
There are many reasons why ovulation might not work as it should, and understanding these can help guide the right treatment. Here are a few common reasons why ovulation doesn’t happen like it should:
Polycystic Ovary Syndrome (PCOS):
Polycystic Ovary Syndrome (PCOS) is a common condition caused by a hormone imbalance that can disrupt ovulation, making it harder to conceive. If you have any of the following symptoms, it is important to talk to your doctor:
- Irregular periods or no periods at all.
- Excess hair growth (hirsutism), often on the face, chest, or back.
- Acne or oily skin.
- Weight gain or difficulty losing weight.
- Thinning hair or hair loss from the scalp.
- Difficulty getting pregnant.
The good news is that PCOS can be managed. Common treatments include:
- Ovulation-stimulating medications
- Insulin-sensitising medications
- Hormonal treatments or injections
- Options like IVF might be recommended if other treatments are not successful.
With the right care and support, many women with PCOS go on to have healthy pregnancies.
Thyroid issues:
Thyroid problems, whether an overactive thyroid (hyperthyroidism) or an underactive thyroid (hypothyroidism), can interfere with ovulation and make it harder to conceive.
The thyroid, a small gland in your neck, produces hormones that regulate your metabolism and play a key role in your menstrual cycle and ovulation.
The good news is that with proper treatment, these conditions can often be managed, helping to restore ovulation and improve your chances of conceiving.
According to Dr. Guimarães, “your fertility doctor will usually run simple blood tests as part of your fertility work-up to check your thyroid function. They will recommend the best course of treatment to help restore your reproductive health.”
Hormonal imbalances:
Hormonal imbalances can disrupt ovulation and make it harder to conceive. Here are some common examples:
- High prolactin levels: Too much prolactin, a hormone involved in milk production, can stop ovulation and cause irregular periods.
- Luteal phase issues: Low levels of progesterone after ovulation can make it harder for a fertilised egg to implant.
- Stress or weight changes: Extreme stress, significant weight loss, or over-exercise can stop signals from the brain to the ovaries, preventing ovulation.
- Adrenal hormone problems: Conditions affecting the adrenal glands, like Cushing’s Syndrome, can lead to irregular cycles and ovulation issues.
The good news is that most hormonal imbalances can be treated. With the right care, ovulation can often be restored, improving the chances of conceiving.
Infertility and your fallopian tubes
The fallopian tubes play a vital role in fertility. In fact, they are pretty amazing. They are not just pathways between the ovaries and uterus but actively guide the egg and support fertilisation.
If the fallopian tubes are blocked or damaged, sperm and egg cannot meet, and natural conception becomes impossible. Common causes include:
- Pelvic inflammatory disease (PID)
- Endometriosis
- Scarring from previous surgeries
- Previous ectopic pregnancy
- Congenital abnormalities
Treatment options for blocked fallopian tubes
- Surgical repair: In some cases, surgery can remove blockages or fix damage.
- IVF (In vitro fertilisation): If surgery is not an option, IVF allows fertilisation to happen outside the body, bypassing the fallopian tubes entirely.
Infertility and endometriosis
Endometriosis is a condition where tissue similar to the lining of the uterus grows outside it, often on the ovaries, fallopian tubes, or pelvis. This tissue reacts to menstrual hormones, causing pain and inflammation.
Endometriosis can affect fertility by:
- Damaging ovaries or fallopian tubes.
- Making it harder for sperm and egg to meet.
However, treatment options like medication, surgery, or assisted reproductive technologies (e.g., IVF) can help.
For some women with advanced endometriosis and low ovarian reserve, egg donation may be the best option for achieving pregnancy.
Dr. Guimarães says: “If you have endometriosis and are planning to conceive, it is essential to see a fertility doctor as soon as possible, as timely treatment can make a big difference.”
Infertility and adenomyosis
Adenomyosis is when the uterine lining grows into the muscle wall, causing heavy periods, cramps, and pelvic pain. It can make it harder to conceive by affecting implantation or increasing miscarriage risk. Treatments like medication, IVF, or surgery can help, so speak to a fertility doctor about your options.
Infertility and your uterus
The uterus is where a fertilised egg implants and grows, so any issues can affect this critical step. Implantation is when the egg attaches to the uterine lining (endometrium), but certain conditions can make it harder:
- Uterine fibroids: Non-cancerous growths that can block the egg or make implantation difficult.
- Endometrial polyps: Small growths on the uterine lining that disrupt implantation.
- Endometrial thickness issues: A lining that is too thick (hyperplasia) or too thin (hypoplasia) can prevent successful attachment.
- Uterine abnormalities: Structural differences like a bicornuate or septate uterus can interfere with implantation or increase miscarriage risk.
These conditions are often diagnosed through imaging tests, and treatments like surgery or medication may help. Many women still achieve healthy pregnancies with the right care.
Infertility and your genes
Genetic conditions can sometimes affect fertility by making it harder to conceive or carry a pregnancy. Examples include:
- Turner Syndrome: Women with only one X chromosome may have smaller ovaries and irregular ovulation.
- Fragile X Syndrome: This condition can cause premature ovarian failure, where the ovaries stop working before age 40.
Genetic testing can identify these conditions. While they cannot be cured, options like donor eggs or embryos can help. A fertility doctor can guide you to the best solutions for your situation.
Autoimmune conditions
Autoimmune conditions, like lupus or rheumatoid arthritis, can affect fertility when the immune system mistakenly attacks reproductive tissues.
Managing these conditions with proper medication is key. Blood tests and symptom reviews help diagnose them. In some cases, fertility treatments combined with therapies to calm the immune system can improve the chances of pregnancy.
Causes of male infertility
Infertility isn’t just a women’s issue—it affects men too, and it’s more common than you might think. Just like with female infertility, there are various reasons why a man might have trouble contributing to a pregnancy.
Infertility and sperm production
One of the most common causes of male infertility is related to sperm production. This includes issues like:
- Low sperm count: When the number of sperm produced is lower than normal, it reduces the chances of one sperm successfully fertilising the egg.
- Poor sperm motility: Motility refers to how well the sperm can swim. If the sperm aren’t moving properly, they may struggle to reach the egg.
- Abnormal sperm morphology: The shape of sperm can affect its ability to penetrate and fertilise an egg. Abnormally shaped sperm may have difficulty in this crucial step.
What causes poor sperm quality?
Sperm production issues can be caused by a variety of factors, including genetic conditions, infections, hormonal imbalances, and even lifestyle factors like smoking, excessive alcohol consumption, or exposure to certain toxins.
Improving sperm health often starts with lifestyle changes. The following can can boost sperm count and quality:
- Quitting smoking
- Reducing alcohol
- Eating a balanced diet
- Exercising regularly, and
- Managing stress.
If these changes are not enough, additional treatments can help:
- Medications or supplements: Hormones or vitamins like zinc and folic acid can support sperm production.
- Treating infections: Antibiotics can address infections affecting sperm health.
- Surgery: Procedures like correcting varicocele or clearing blockages can improve sperm function.
If these steps do not lead to conception, assisted reproductive technologies (ART) may be the next option:
- IUI: Sperm is placed directly into the uterus.
- IVF with ICSI: A single sperm is injected directly into an egg, ideal for low sperm count or motility issues.
Hormonal imbalances
Hormones are essential for sperm production, and imbalances can cause fertility issues. Common causes include:
- Low testosterone: This key hormone drives sperm production, so low levels can reduce sperm count.
- Pituitary gland problems: The pituitary gland sends signals to the testes to produce sperm, and disruptions can impact this process.
The good news is that hormonal imbalances can often be treated with medication. Identifying these issues early can make a big difference in improving fertility.
Blockages in the reproductive tract
Sometimes sperm can’t be ejaculated because of blockages in the tubes that carry it. This can happen due to:
- Infections: Scarring from STIs or other infections.
- Injuries or surgeries: Past procedures in the groin area.
- Congenital conditions: Being born with missing or blocked reproductive parts, like the vas deferens.
Treatment might include surgery to remove blockages. If that’s not an option, sperm can be retrieved directly from the testes using:
- TESA (testicular sperm aspiration): A needle extracts sperm.
- TESE (testicular sperm extraction): A small incision collects sperm.
Your doctor will help you decide the best approach for your situation.
Genetic factors
Genetic conditions can affect sperm production or function. Examples include:
- Klinefelter Syndrome: An extra X chromosome leads to low testosterone and reduced sperm production.
- Y Chromosome Microdeletions: Missing sections of the Y chromosome disrupt sperm production.
While these conditions can’t be cured, treatments like donor sperm can help.
Varicocele
A varicocele occurs when veins in the scrotum become enlarged, raising testicle temperature and affecting sperm quality. It’s a common cause of male infertility but can often be treated with minor surgery to improve sperm health and boost conception chances.
At Procriar, our Urology and Andrology team can help determine if this treatment is right for you.
Start your journey towards fertility with Procriar
Infertility can feel overwhelming, but it’s a medical condition—one that can often be treated with the right care and support.
At Procriar, we combine advanced fertility treatments with compassionate, personalised care to guide you every step of the way.
Whether you’re just starting or looking for answers, our specialists are here to help you take the first step toward building your family.