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  • Becky

Why Can’t I Get Pregnant? A Guide to Primary and Secondary Infertility

Updated: Mar 29, 2023

When people think about infertility, they’re usually thinking about primary infertility, or infertility affecting women who have no children. However, secondary infertility, or infertility affecting women who have already had one or more children, is very real, and no less painful.

What is infertility?

Both primary and secondary infertility are defined as an inability to get pregnant after 1 year of unprotected sex for a woman under 35, or after 6 months for a woman over 35.

When you’ve decided the time is right for a baby, 1 year or even 6 months might seem like a really long time, so let me explain:

A completely fertile woman in her 20s only has about a 20% chance of getting pregnant in any given menstrual cycle. Therefore, even without any problems at all, it could still take many cycles for her to get pregnant. The chance of getting pregnant each month decreases as we get older and egg quality declines (which is natural and not in and of itself indicative of a problem), so it makes sense that you want to allow yourself sufficient time to get pregnant naturally before you begin to suspect a problem.

Even if you don’t get pregnant within that year or 6 month period, there still might not be a problem, and you very well may get pregnant naturally. But you should head to the doctor to make sure.

How Many Women Struggle with Primary and Secondary Infertility?

According to the CDC, about 1 in 5 (19%) women between the ages of 15 and 49 who have never had a child will struggle with infertility. Secondary infertility affects about 1 in 17 (6%) women. Secondary infertility, therefore, is less common, but still a pretty sizeable issue.

Additionally, among women who have never had a child, 1 in 4 will have trouble carrying a baby to term, as will 1 in 7 women who already have a child.

In all cases of primary and secondary infertility, roughly:

33% are caused by problems with the woman

33% are caused by problems with the man

33% are caused by a combination of problems in both the man and the woman, or are unexplained.

Causes of Primary and Secondary Infertility in Women

All primary and secondary fertility issues in women fall into one of three categories: problems with ovulation, problems with the fallopian tubes, or problems with the uterus.

A diagram of the female reproductive systems to help understand primary and secondary infertility.
The female reproductive system.

Problems with Ovulation

Ovulation, or the process through which a woman releases an egg each month, is controlled by the rise and fall of many different hormones. When the balance of these hormones gets knocked out of whack and your body doesn’t receive the correct signals, ovulation doesn’t happen correctly and sometimes it doesn’t happen at all.

Polycystic Ovary Syndrome (PCOS)

PCOS is a hormone disorder that affects between 6 and 12% of women. The condition causes a woman’s ovaries to produce lots of small, fluid-filled cysts which in turn produce androgens, or male sex hormones. Women usually have only a small amount of androgens in their bodies, so the result is a hormone imbalance that can lead to problems with ovulation and the menstrual cycle, as well as the other common symptoms of PCOS such as excess body hair, thinning hair, and weight gain.

Thyroid Problems

Your thyroid gland sits in the front of your neck and is responsible for producing certain hormones. There are some conditions like Hashimoto’s Disease that cause your thyroid to underproduce (hypothyroidism), and other conditions like Graves’ Disease that cause your thyroid to overproduce (hyperthyroidism). Neither situation is ideal for fertility and both can potentially disrupt your menstrual cycle.

Hypothalamus and/or Pituitary Gland Problems

They hypothalamus and pituitary glands are located inside your brain and work together to control the levels of key fertility hormones such as follicle stimulating hormone (FSH) and luteinizing hormone (LH). A problem with either gland can result in a hormone imbalance that can cause ovulatory problems.


Amenorrhea is the lack of a menstrual period. Amenorrhea can have many causes, including the problems I’ve already discussed. But I want to draw particular attention to functional hypothalamic amenorrhea, sometimes also referred to as exercise induced amenorrhea. As the name implies, it is caused by frequent, strenuous exercise. However, it can also be triggered by poor nutrition, as well as stress.

Problems with Fallopian Tubes

Each month when your body releases an egg during ovulation, the fimbriae at the ends of the fallopian tubes are in charge of sweeping the egg into the tube, which it then travels through to reach your uterus. If there is damage to, or a blockage in any part of your fallopian tubes, it becomes difficult or impossible for the egg to reach your uterus.

Additionally, if either of your tubes is filled with fluid, it will be nearly impossible for a fertilized egg to implant in your uterus because the fluid continually washes into your uterus and dislodges the egg.


Endometriosis occurs when tissue from your uterus grows outside your uterus, usually within your abdominal cavity, but sometimes outside of it, too. Endometriosis can be a painful, debilitating condition, or it can be pretty silent as it was in my case. It is, however, one of the most common causes of fallopian tube damage. You see, when the rogue endometrial tissue grows in, on and around your tubes, it can block the tubes or create scar tissue that inhibits their proper functioning. It can also grow around your ovaries and inhibit their ability to release an egg.

Pelvic Inflammatory Disease (PID)

Pelvic inflammatory disease is an infection of the pelvic and reproductive organs. It can be caused by any one of a number of pathogens, some of which are sexually transmitted and some of which are not. PID can be very sneaky, and it’s possible to have it without ever having symptoms. Infections that are not treated can lead to scarring in the fallopian tubes which can, again, lead to blockages.

Problems with the Uterus


Uterine fibroid are noncancerous growths inside the uterus, which can range in size from very small to pretty big. They can block the fallopian tubes, change the shape of the uterus, and make it difficult for an egg to implant.

Other structural issues

There are other uterine structural abnormalities that can make it difficult to get pregnant. Most of these are not terribly common.

A table presenting some common causes of primary and secondary infertility, along with their causes.

Causes of Infertility in Men

Male infertility is all about the sperm. Low sperm count can play a role, as can production of misshapen sperm, or sperm that don’t move as they should.

What if no one can figure out why I can’t get pregnant?

Unexplained infertility is the term used to describe cases where doctors are unable to figure out why you’re not able to get pregnant. I’ve written an article exploring some possible causes of unexplained infertility, which I encourage you to read if you’ve been given this diagnosis.

Is there anything else that sets secondary infertility apart?

Infertility of any kind can be devastating and alienating. However, the emotional aspect of secondary infertility can sometimes be quite different from that of primary infertility.

In addition to all the usual feelings and emotions surrounding infertility, many women dealing with secondary infertility also feel ashamed (or shamed!) and selfish for wanting another child so badly when they already have one. This feeling can be compounded when they have friends or relatives who are struggling with primary infertility.

On top of that, when we think of infertility as a society, we usually only think about primary infertility, and this can lead to insensitivity, misunderstanding, and further hurt.

Schedule a free call to learn how I can help you maximize your fertility naturally.


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