People who are born with two ovaries have one on each side of the uterus. The ovaries are part of the female reproductive system and are responsible for the production of hormones, including estrogen and progesterone.

People with ovaries can develop tumors or cysts on their ovaries. Usually these are benign — not cancerous — and will stay in or on the ovaries.

Less commonly, ovarian tumors are cancerous. Some ovarian tumors cause abnormal vaginal bleeding or missed periods, but it’s unlikely to be the only symptom.

Read on to learn more about the link between a missed period and ovarian cancer.

A period is considered missed when it skips an entire cycle. Most menstrual cycles are between 21 and 35 days. Cycle lengths will not vary much from month to month, but it’s not uncommon for a period to be a few days late or early.

For some people, menstrual cycles are irregular and the length varies widely from month to month. It’s a good idea to keep track of your cycle so you know your body’s rhythm. You can do this by marking a calendar or using a tracking app.

Make an appointment with your doctor if your period hasn’t arrived after about 40 days, especially if you normally have regular cycles.

Most of the time, missed periods are not a cause for concern. Pregnancy, stress, strenuous exercise, low body fat, or hormonal imbalances can cause menstrual irregularities.

In rare cases, irregular periods are a sign of something serious. They may also increase your risk of ovarian cancer.

A 2016 study found that women with a history of menstrual irregularities were twice as likely to develop ovarian cancer. This risk increases with age.

Irregular or missed periods aren’t the most common symptom of ovarian cancer. There are other more common symptoms.

Contact your doctor if you’re concerned about ovarian cancer, have a family history of cancer, or notice anything different in your monthly cycle.

Many people will not have symptoms in the early stages of ovarian cancer.

When symptoms do occur, they may be vague and mild, indicating other conditions such as irritable bowel syndrome (IBS). This can lead to a delay in diagnosis and treatments.

Make an appointment with your doctor or gynecologist if the following symptoms occur more than 12 times per month:

If you do have ovarian cancer, early diagnosis is key. Make sure you don’t ignore these symptoms, especially if they persist.

Some factors can increase your risk for ovarian cancer. It’s important to understand your risks, as well as the symptoms of ovarian cancer. This knowledge may help with early detection and treatment, which improves outcomes.

Risk factors for ovarian cancer include:

  • Age. Older women are more likely to develop ovarian cancer. Around half of women with ovarian cancer are 63 years or older.
  • Weight. Women who have obesity have a higher risk of developing ovarian cancer. Obesity is medically classified as having a body mass index (BMI) of 30 or higher.
  • Race. The CDC reports that white women are more likely to develop ovarian cancer than Black or Latinx women. However, inequities in healthcare may be a factor in this data.
  • Family history. Up to 25 percent of ovarian cancers are linked to inherited changes or mutations in specific genes. One such genetic mutation is BRCA. Women with the BRCA1 mutation have a 35–70 percent lifetime risk of developing ovarian cancer.
  • No birth control. Oral contraceptives can lower your risk for ovarian cancer. The longer the use, the lower your risk, which continues even after you stop taking the pill. It takes at least 3 to 6 months of consecutive use before the benefits kick in.
  • Fertility drugs. Fertility medication may increase a woman’s risk for ovarian tumors. More studies are needed, but initial research suggests that the risk is especially high for women who don’t get pregnant as a result of these fertility drugs. In addition, women who experience infertility may be at increased risk of developing ovarian cancer.
  • Hormones. According to the American Cancer Society (ACS), estrogen therapy used after menopause may increase your risk for ovarian cancer.
  • Reproductive history. Women who have their first full-term pregnancy at age 35 or older or have never had children are at a higher risk for ovarian cancer. The risk is lower for women who have children before the age of 26. The risk decreases with each full-term pregnancy, as well as with breastfeeding.
  • Menstrual pain. One study suggests that menstrual pain is associated with an increased risk of epithelial ovarian cancer.

Early diagnosis leads to a better outlook for ovarian cancer. About 94 percent of people who get treatment for ovarian cancer in the early stages live longer than 5 years after diagnosis.

But only about 20 percent of ovarian cancers are discovered at an early stage. This may be because many of the symptoms are vague and nonspecific, and thus often ignored or attributed to other causes.

During your appointment, your doctor may conduct a pelvic exam and a Pap smear to check for a variety of issues. They will perform an exam to feel your ovaries for size, shape, and consistency.

Although preventive tests like pelvic exams and Pap smears can help guide your doctor toward a diagnosis, a surgical approach is sometimes needed to confirm whether you have ovarian cancer.

Screening tests

There are no screening tests for ovarian cancer yet. But other tests can provide information that help interpret results, especially in people who don’t have symptoms.

Two tests that can be used to help inform an ovarian cancer diagnosis are:

While these tests may help guide your doctor to detect tumors before symptoms develop, they haven’t been proven to decrease the mortality rate of people with ovarian cancer. As a result, they’re not routinely recommended for women at average risk.

They also can’t definitively confirm an ovarian cancer diagnosis without a surgical approach such as the removal of the ovary. They can only help guide your doctor toward the source of the issues you’re experiencing.

Many people don’t notice symptoms until ovarian cancer has progressed to an advanced stage. But knowing what symptoms to look for can help with early detection.

Make an appointment with your doctor if you’re worried about your cancer risk or unexpectedly miss your period.