What Causes Infertility in Women? PCOS, Cysts, Genetics, and More

Complete Healthcare Team

Infertility is far more common than most people realize, and it’s rarely the result of anything a person did wrong. It affects roughly 1 in 5 women who have not had a prior birth, and the causes are usually medical and often treatable. The internet is also full of viral claims about it, from energy drinks to matcha, that range from partly true to completely made up. This is a clear look at what actually causes infertility in women, plus honest answers about the myths worth ignoring.

Understanding the real causes is the first step toward getting answers, and you don’t have to sort through it alone. The gynecology team at Complete Healthcare helps people navigate fertility questions regularly, and this guide covers the most common causes, the warning signs, whether genetics play a role, and which trendy fears actually hold up.

What Counts as Infertility

Infertility is generally defined as not being able to get pregnant after a year of regular, unprotected sex, or after six months if you’re over 35. It’s a recognized medical condition, not a personal failing, and it’s common. According to the CDC, about 1 in 5 married women aged 15 to 49 with no prior births are unable to get pregnant after a year of trying.

It’s also worth knowing that infertility isn’t only a women’s issue. Both partners can contribute, and causes are divided across female factors, male factors, a combination of both, and cases where no clear cause is found. This article focuses on female-factor causes, but a full evaluation usually looks at both partners.

The Most Common Causes of Female Infertility

Most female infertility comes down to a problem somewhere in the process of ovulating, fertilizing an egg, or maintaining a pregnancy. Here are the leading causes.

Ovulation problems. Difficulty ovulating, whether irregularly or not at all, is behind a large share of female infertility. If an egg isn’t released, it can’t be fertilized. Irregular or absent periods are the most common sign.

PCOS (polycystic ovary syndrome). PCOS is the most common cause of female infertility. It’s a hormonal condition that disrupts ovulation, often causing irregular periods, elevated androgen levels, and small fluid-filled sacs on the ovaries. We’ll come back to it, since it generates a lot of specific questions.

Blocked or damaged fallopian tubes. If the tubes are blocked, sperm and egg can’t meet. This is often caused by pelvic inflammatory disease, past infections, or endometriosis.

Endometriosis. This is a condition where tissue similar to the uterine lining grows outside the uterus, which can affect the ovaries, tubes, and egg quality, and is a recognized cause of infertility.

Uterine or cervical issues. Fibroids, polyps, or structural differences in the uterus can interfere with implantation or pregnancy.

Primary ovarian insufficiency. Sometimes called premature ovarian failure, this is when the ovaries stop working normally before age 40, sometimes due to genetics, autoimmune conditions, or medical treatments like chemotherapy.

Age. Fertility naturally declines with age, particularly after the mid-30s, as both the number and quality of eggs decrease. This is a normal biological process rather than a disorder.

Signs of Infertility Worth Paying Attention To

Infertility itself often has no symptoms beyond difficulty conceiving, but certain signs can point to an underlying cause worth evaluating. These include:

• Irregular, absent, or unpredictable periods, which can signal ovulation problems
• Very heavy, painful, or long periods, which can accompany conditions like endometriosis or fibroids
• Pain during sex or chronic pelvic pain
• Signs of hormonal imbalance, such as significant acne, excess hair growth, or unexplained changes in weight
• Known conditions like PCOS, thyroid disorders, or a history of pelvic infections

Noticing one of these doesn’t mean you’re infertile. It simply means it’s worth a conversation, especially if you’re trying to conceive or planning to.

Does PCOS Cause Infertility?

Since this is one of the most searched questions, it deserves a direct answer. Yes, PCOS can cause infertility, and it’s the most common cause, but having PCOS does not mean you can’t get pregnant. PCOS interferes with fertility mainly by disrupting ovulation, meaning eggs aren’t released regularly or at all. The encouraging part is that this is often treatable. According to the FDA, options to improve the chances of pregnancy with PCOS include lifestyle changes, ovulation-inducing medications, and other medical approaches. Many people with PCOS go on to have healthy pregnancies, sometimes with support and sometimes without.

Can an Ovarian Cyst Cause Infertility?

This one deserves nuance. Most ovarian cysts are harmless, common, and don’t affect fertility at all. Many form as a normal part of the menstrual cycle and resolve on their own. However, certain types can affect fertility. Cysts related to endometriosis (endometriomas) or to PCOS can be associated with infertility, and large cysts can occasionally interfere with ovulation or require treatment. So a simple, functional cyst is usually nothing to worry about for fertility, while cysts tied to an underlying condition are worth evaluating. If you’ve been told you have an ovarian cyst and you’re concerned about fertility, that’s a reasonable thing to ask a provider about.

Is Infertility Genetic?

Genetics can play a role, though infertility is rarely inherited in a simple, direct way. Several causes of infertility have genetic components. PCOS tends to run in families, primary ovarian insufficiency can be linked to genetic conditions, and certain chromosomal differences can affect fertility. Endometriosis also appears to have a hereditary tendency. That said, having a family history doesn’t mean you’ll be infertile, and plenty of people with no family history experience infertility. If close relatives have had fertility challenges or early menopause, it’s useful information to share with your provider, but it isn’t a verdict.

Myths and Wives’ Tales, Sorted From Facts

The internet has produced a lot of fertility fears, and some deserve a clear, evidence-based response. Here’s where a few common ones actually stand.

Do energy drinks cause infertility?

Not directly, despite viral claims. There’s no solid evidence that any specific energy drink causes infertility. The legitimate kernel is caffeine: very high caffeine intake may be associated with taking longer to conceive, and energy drinks can be high in both caffeine and sugar. Most fertility guidance suggests keeping caffeine under about 200 mg per day when trying to conceive. So the reasonable move isn’t panic, it’s moderation.

Does matcha cause infertility?

No. There’s no credible evidence that moderate matcha consumption harms fertility. Matcha contains caffeine, roughly 60 to 70 mg per serving, which is less than a typical cup of coffee, and it also contains antioxidants. One to two servings a day sits comfortably within the general caffeine guidance. The matcha-causes-infertility claim is essentially a myth, as long as your total caffeine stays moderate.

A few others worth dismissing.

Using birth control in the past does not cause long-term infertility. A single missed or irregular period doesn’t mean you’re infertile. And stress alone, while it can affect cycles, is not a standalone cause of infertility in the way folklore suggests. When in doubt, the pattern holds: total lifestyle context matters more than any single trendy villain.

When to Talk to a Provider About Fertility

It’s reasonable to seek an evaluation if any of these apply:

• You’ve been trying to conceive for a year, or six months if you’re over 35
• You have irregular or absent periods or signs of a hormonal condition
• You have a known condition like PCOS, endometriosis, or a history of pelvic infections
• You’re planning ahead and want to understand your fertility before trying

In our practice, we’d always rather someone come in with questions early than wait and worry, since many causes of infertility are more manageable when identified sooner.

Get Answers About Your Fertility

If you have questions about your fertility, irregular cycles, PCOS, or anything else covered here, a provider can help you understand what’s going on and what your options are. Complete Healthcare offers gynecology care with same-day appointments available across our 11 locations in Central Ohio, including Columbus, Pickerington, Newark, Lancaster, Marion, Marysville, and Delaware. Call us at 614-882-4343 or schedule online to get started.