What Are the Unique Challenges of Subfertility In Women?

You've likely heard of infertility, the inability to get pregnant naturally after an entire year or more of trying to conceive. Less commonly discussed is subfertility, or a delay or difficulty in conceiving.

How common is subfertility?

Subfertility affects one in six couples, according to a 2019 review published in the medical journal Nature Reviews. Half of those couples have no known cause for their delay in conceiving.

"Being subfertile, rather than infertile, usually means that it's still possible to conceive naturally. If you're infertile, you have the inability to conceive naturally after trying for years," said Jane L. Frederick, M.D., reproductive endocrinologist and medical director of HRC Fertility in Orange County, California. "These two terms are often used together, but they are different. In subfertility, it just takes longer than the average to conceive naturally."

There can be some overlap between the diagnoses of infertility and subfertility, explained Molly Santosuosso, N.M.D., a preconception and fertility care specialist at Natural Kid Doc in Scottsdale, Arizona.

"Infertility generally requires medical assistance, such as in-vitro fertilization, to conceive. On the other hand, subfertility refers to someone who is able to become pregnant naturally but may take longer to do so," Santosuosso said.

When does subfertility cross into infertility territory?

"Where it can become confusing is after 12 months of actively trying to conceive but failing to do so, the diagnosis of 'infertility' is made. This diagnosis covers couples that are both struggling with infertility and subfertility, rather than making the distinction between the two."

What are the causes of subfertility in women?

Underlying conditions cause some cases of subfertility, while others have no identifiable cause. For women with underlying conditions, depending on the situation and its severity, some may receive a diagnosis of infertility and require intervention to get pregnant. For other women, lifestyle changes can alleviate their subfertility and lead to them conceiving naturally.

Let's look at the factors that can lead to a higher risk of subfertility and infertility for women.

Egg quality and quantity

As we get older, egg quantity and quality decline, potentially making pregnancy all the more difficult.

"The quality and quantity of our eggs are dropping rapidly in our 30s and even more rapidly in our 40s, so the age of the woman is very critical in terms of how long you try to conceive," Frederick explained.

Ovulatory disorders

"Causes of subfertility for women are commonly related to ovulation dysfunction," Santosuosso stated. "Ovulation is required for pregnancy to occur and only occurs one day each menstrual cycle. If no ovulation occurs, there is no chance a pregnancy can occur."

Santosuosso said conditions that impact ovulation and lead to subfertility include:

• Polycystic ovarian syndrome (PCOS)
• Premature ovarian insufficiency, or premature menopause
• Diminished ovarian reserve (reduction in egg count)

Fallopian tube or uterine damage

It’s what’s inside that counts. Unfortunately, some past procedures or health conditions affecting the uterus and fallopian tubes can impact fertility. Scar tissue or adhesions can reduce the amount of available space in your uterus, such as with Asherman’s syndrome.

"Endometriosis, previous surgical procedures, pelvic inflammatory disease, and a history of some sexually transmitted infections can all cause changes within the fallopian tubes. These changes can make it challenging for the egg to travel from the ovary to meet the sperm for pregnancy to occur," Santosuosso said.

"Conditions directly affecting the uterus, such as fibroids, can also contribute to subfertility," she continued. "Fibroids are growths within the uterus itself that can make it challenging for implantation of a fertilized egg into the uterus to occur and may inhibit sperms' ability to travel to meet an egg."

Chronic conditions

Several other chronic diseases or health conditions can contribute to subfertility in women. These chronic illnesses may reduce or suppress ovulation, making it harder to become pregnant via sexual intercourse.

These conditions include:

• Thyroid dysfunction
• Adrenal gland and pituitary disorders
• Autoimmune diseases, such as rheumatoid arthritis
• Heart disease
• Diabetes

Lifestyle factors

The foods you eat and the amount of exercise you get can significantly affect subfertility.

"The more we talk about lifestyle changes, I think we can really make an effort to reduce issues of subfertility in patients," Frederick said.

She advised the following lifestyle changes for both men and women if you are trying to get pregnant, as they can affect both male and female fertility:

• Avoid smoking, vaping (nicotine) and marijuana.
• Decrease your alcohol consumption.
• Decrease caffeine intake.
• Maintain a healthy weight. Being underweight or overweight will impact your chances of becoming pregnant.
• Avoid saunas and Jacuzzis.
• Avoid excessive exercise.

Speak with your doctor to learn what kind of changes you should consider to increase your chances of conceiving.

Sex at the wrong times—or too much sex

Frederick recommended over-the-counter ovulation predictor kits to make sure you're having sex at the times most likely to result in a pregnancy (when you're ovulating).

"It's important to figure out the best time during the cycle to have intercourse rather than just trying to have intercourse randomly," she explained. "Oftentimes, people will tell me that they are having intercourse every day, which causes the sperm count to become too low to actually help patients conceive."

If you have regular periods, tracking your basal body temperature throughout the month is another way to determine when you're ovulating and, therefore, most likely to conceive.

How is subfertility diagnosed?

Your doctor will diagnose subfertility with several tests, including a blood test, imaging tests and a thorough fertility and medical history, Santosuosso explained.

Santosuosso said common tests for subfertility include:

• Female hormone levels for estradiol, follicle-stimulating hormone (FSH), luteinizing hormone (LH) and progesterone, which help assess ovarian function, egg reserve and ability to maintain a pregnancy.
• Thyroid-stimulating hormone (TSH) and other thyroid hormones (T3, T4) to assess thyroid function.
• Looking for elevated levels of the hormone prolactin which can cause ovulatory dysfunction.
• Transvaginal ultrasound to detect fibroids, cystic ovaries, polyps and other structural concerns.
• Hysterosalpingogram may also be used to view the fallopian tubes and uterine cavity to detect any blockages, fibroids, polyps or scarring.

When should you see a doctor for trouble conceiving?

The general recommendation regarding female infertility is if you're under the age of 35 and have been trying to conceive for a year, or if you're between the ages of 35 and 40 and have been trying for six months without success, then you may want to talk to a fertility specialist. Anyone over 40, "... should just go straight to a specialist and have testing," Frederick advised.

Additionally, if you have underlying health conditions or menstrual cycle irregularities that can increase your risk factor for infertility, talk to a fertility specialist as early as possible about your pregnancy goals.

"If someone experiences abnormalities in their menstrual cycle, whether that be significantly heavy periods, significantly painful periods, lack of periods, or infrequent periods, I always recommend seeking out care earlier," Santosuosso said.

"If you're taking longer to conceive, I often tell patients that they should go to their doctor and talk about what medications they're on," Frederick said.. "Maybe they don't realize that their medication has a slight effect on fertility. It's just being aware of what you're taking and then asking those questions of your doctor."

That advice applies to male infertility too.

What is the treatment for subfertility or infertility?

Based on the results of the blood and imaging tests, your doctor can determine if you are subfertile or infertile and advise the best treatment. Treatment depends on the underlying reasons for your delay in conceiving.

Treatment may include lifestyle changes, fertility drugs, surgery or assisted reproductive technology, such as in-vitro fertilization (IVF) or intrauterine insemination (IUI).

It's also important to remember that subfertility and infertility are common and often treatable conditions.

"I wish that more women and couples would know that they're not alone," Frederick said. "I think that the more that we share our stories and our struggles, the more that people will realize that this is a common diagnosis that occurs in every reproductive age group."

"So, don't give up hope," she continued. "There are specialists out there and we would love to meet and help those patients conceive. Many times we have lots of successes with simple lifestyle changes and simple treatment cycles."

The bottom line

Couples trying to conceive, yet can’t, in under a year may be experiencing subfertility. Once the year mark passes, couples may want to schedule an infertility evaluation to discover the cause. Fertility treatment could include medication, lifestyle changes, or assisted reproductive surgery. The most effective course of treatment may combine multiple options.

If you are experiencing subfertility, there is hope. But it’s important to see a medical professional that can help you achieve the best outcome. Giddy Telehealth offers a convenient online portal and many healthcare providers offer same-day appointments or video consultations.