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Women's Health

Irregular Periods and Infertility: Possible Causes

August 1st, 2019 | 7 min. read

By Christina Dias, RN, BSN

Ah, the menstrual cycle. One of nature’s most misunderstood phenomena.

But it doesn’t have to be! Irregular periods and infertility are often topics we don’t wish to talk or think about, but as long as you know the facts and your options, your goals will be much more manageable.

But what causes such erratic behavior in some of our cycles? Many factors can contribute to its irregularity, making it longer or shorter, or cause your body to skip cycles altogether. The good news is that even with irregular periods, it’s very likely you can still get pregnant! Unfortunately, it might make planning a pregnancy more challenging.

That’s where we come in. We’re here to help you understand why this might be happening and what you can do about it.

What is a Regular Cycle?

Let’s start with understanding what a cycle should look like…

Lasting roughly 28 days long—about the length of the moon’s monthly revolution around the earth—this hormonal cycle prepares female reproductive organs for a possible pregnancy. Around day 14 of your cycle, ovulation occurs. This is when hormonal spikes cause a mature egg to be released from the ovaries and pushed down the fallopian tube where the egg meets one of two fates. Either it will be joined with and fertilized by a sperm, resulting in pregnancy, or the egg will be discarded through the process of menstruation, where the lining of the uterus is shed. This latter fate is called your period and causes inconvenient bleeding for about four to eight days every month, signaling the end of the cycle. The presence of menstrual blood begins, and the cycle starts all over again. Rinse and repeat.


Irregularity and Infertility: Possible Conditions that Link the Two

Polycystic Ovary Syndrome (PCOS)

One of the most frequent causes of irregular periods, affecting 1 out of every 10 women, is called Polycystic Ovary Syndrome, or PCOS. In short, it’s a hormonal imbalance. Imbalances of hormones involved in the reproductive process can cause problems at various points along the ovulation cycle, affecting the development of the egg or even impacting when the egg is released into the uterus. This causes irregular or missed periods. Unfortunately, there isn’t a definitive cause for PCOS but often times there is an unusually high presence of androgens (testosterone) or excess insulin. Sometimes an inflammation of the ovaries is to blame.

Fortunately, symptoms of PCOS can be managed either through lifestyle changes or with the aid of medications. Women who are overweight or have a family history of diabetes have a higher chance of developing PCOS and so losing weight and improving overall health is one of the first lines of defense. Birth control medications can help regulate your cycle and other medications can enhance or block various hormonal levels. If these steps do not work, In Vitro Fertilization (IVF) has a high success rate for PCOS.

For more information on PCOS, check out our video series here.


Thyroid Imbalances

Do you have unexplained weight loss, an increased appetite, difficulty sleeping, and a perplexing amount of nervousness or anxiety? Or maybe you’re experiencing the opposite: weight gain, fatigue, and constipation? These symptoms might mean your thyroid—a tiny gland in your neck that regulates metabolism—isn’t working quite right. When it overproduces thyroid hormones—a condition known as hyperthyroidism—it sends your metabolism into overdrive. When it under-produces thyroid hormones—known as hypothyroidism—it causes your body to slow down and feel sluggish.

It can also disrupt your ovulation cycle since thyroid hormones send signals to your ovaries. That means that thyroid dysfunction can impact your ability to get pregnant.

In hyperthyroidism (an overactive thyroid), the flooding of thyroid hormones causes an overall elevation of luteinizing hormone (LH), the same hormone that kicks off ovulation. But when LH is already elevated, the increase of LH during your ovulation cycle isn’t enough to signal ovulation to begin. On the other hand, hypothyroidism (an underactive thyroid) causes low LH levels, which means there isn’t enough LH to cause ovulation to start. Either way, a thyroid disorder makes it more difficult for your body to ovulate. And if you can’t ovulate, you can’t get pregnant.

Fortunately, there are easy daily medications that either block thyroid hormone production (for hyperthyroid) or that can replace them with synthetic hormones (for hypothyroid). Depending on the cause and severity of your thyroid disorder, there are also more permanent treatments, including thyroid surgery. Once thyroid levels are restored, your cycle should get back on track, too. But it will be important to monitor your thyroid throughout and after pregnancy.



Intense and unusual pain during the menstrual cycle, during intercourse, or generally in your pelvic area can be due to a condition called endometriosis. Endometriosis occurs when the endometrium—the tissue that lines the uterus—attaches and grows outside of the uterus. It can grow in the ovaries, fallopian tubes, outer surface of the uterus, or anywhere inside the lower abdominal region. It’s more common than you might imagine... it is estimated that about 11% of women of childbearing age have this condition. Although we don’t know why some women develop endometriosis, researchers have some hunches. The lining of the uterus during your period can get backlogged instead of shed. In other cases, the immune system may not be strong enough to fight off leftover tissue before it attaches elsewhere. And the disease seems to run in families, suggesting a genetic link. Hormonal imbalances, too, are thought to possibly play a role.

These growths are typically benign but most significantly impact your ability to get pregnant. For instance, imagine if this abnormal tissue growth blocks your fallopian tubes or impacts the lining of the uterus—it could block your ability to ovulate or make it impossible for an embryo to implant. There are many reasons why this condition might endanger the path to pregnancy at various points within the process. While there is no cure for endometriosis, there are successful treatments.

For women trying to get pregnant, temporarily halting ovulation by means of a gonadotropin-releasing hormone (GnRH) agonist can stop the growth and allow for a healthy pregnancy once ovulation is resumed. In severe cases, surgery to remove the abnormal tissue can be an option. Controlling the frequency of periods with hormonal birth control can be successful pain management. Just remember: Many women with endometriosis are able to get pregnant.


Primary Ovarian Insufficiency (POI)

One of the more serious conditions to have an effect on your cycle and ability to conceive is called Primary Ovarian Insufficiency or POI. This rare condition is when ovarian function is impaired in women under the age of 40. Ovaries that don’t function well tend not to release eggs. It also often leads to a decrease in estrogen, which not only impacts your ability to become pregnant but it can cause other health problems such as osteoporosis. Symptoms of POI mimic those of early menopause, such as hot flashes, decreased sexual desire, and irritability. Sometimes this dysfunction can be traced to chromosomal anomalies, autoimmune responses, or genetics, but more often than not, the cause is simply unknown.

Women with POI sometimes have an ovulation cycle and release an egg, which can lead to pregnancy in about five to 10 percent of women with POI. But the frequency and predictability of ovulation is severely impacted, which makes planning a natural pregnancy highly difficult. Unfortunately, there’s no cure or treatment that has shown to restore ovarian function.

Learning you may never be able to conceive due to ovarian failure can be extremely difficult news to receive. It will take time to process the news and grieve the ideals you may have held of becoming pregnant and bearing a child with your genetics. However, if carrying a child is important to you, there are alternatives. Many couples facing POI expand their families by seeking out an egg donor and pursuing In Vitro Fertilization. Talk to your fertility clinic about your options. Be sure to have a strong support network in place as you explore possibilities.

What Can I Do to Help Irregular Periods?

A healthy body has the highest chance of getting pregnant. This is the case whether or not you face irregular periods. But in the case of an unpredictable menstrual cycle, improving your overall health and wellness can be the medicine that gets your periods back on schedule. Women who are overweight or have nutritional deficiencies have an increased risk for conditions that cause irregular cycles and so it is recommended to eat a balanced, nutritious diet and start an exercise routine. Be cautious, however, not to overdo the workouts. Extreme physical activity can also cause irregular cycles, as often seen in professional athletes. Make sure to take the time to build up your fitness appropriately.

Menstrual cycles are also highly impacted by emotional stress. It isn’t uncommon for stress to trigger your period or cause your body to skip a cycle. Finding ways of reducing stress—perhaps through techniques such as meditation, yoga, taking breaks from work, or even by prioritizing sleep—can help restore your cycle. Overall wellness is an enormous factor for hormonal imbalances and should be the very first changes you make when facing irregular periods.

When Should I Call a Doctor?

ovulation-when-trying-to-get-pregnantTrack the number of days between the start of your periods. You have an irregular period if you consistently get your period in less than 21 days or over 35 days. It’s time to call the doctor when you’ve had irregular or missed periods for more than three months. When the cycle is upset for a sustained time, there may be an underlying issue. Unusual and deep pain is also a sign that it’s time to get checked out. A board-certified reproductive endocrinologist can monitor your overall health and test for various conditions that may be impacting your cycle and ability to conceive.

Be sure to discuss with your doctor your medical history and any recent changes to your health, including weight loss or gain, unusual hair growth, the intensity and length of your periods, changes to your sleep patterns, prior pregnancies and surgeries, any mental health problems such as depression or anxiety, and any known reproductive problems in genetically related family members.


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Christina Dias, RN, BSN

Christina Dias, RN, BSN joined the team at Illume Fertility in 2004. She currently serves as our Director of Nursing, overseeing our clinical care teams. She received her Bachelor of Science in Nursing from Sacred Heart University.

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