What is infertility and who is affected by it?

Simply put, infertility is defined as the inability to get pregnant after at least one year of having frequent, unprotected sex, or after 6 months if the woman is above 35 years of age. If you and your partner are struggling to conceive, know you’re not alone — 10 to 15 percent of couples in the United States struggle with infertility issues, making infertility fairly common. Infertility affects both men and women, and usually becomes more likely with age.

Infertility is nearly equally caused by both men and women in infertile couples, with the man causing infertility one-third of the time, the woman causing it another third of the time, and the final third being either an unidentified cause or fertility issues in both the man and the woman.

What are the causes of infertility?

Infertility can be a result of a problem with any of the steps involved in initiating a successful pregnancy. In order to get pregnant, a woman’s ovaries must release eggs during ovulation, the egg must meet with a man’s sperm in the fallopian tube, and the fertilized egg must exit the fallopian tube and implant within the walls of the woman’s uterus.

For women, infertility can be caused by the ovaries not properly releasing the egg during ovulation, problems with the menstrual cycle, structural problems in the fallopian tube or uterus, or infections, among many other factors. These problems can be the result of underlying conditions such as uterine or ovarian disorders, endocrine disorders, or many other structural and chemical changes that can occur within the female reproductive system.

Men are a contributing cause for infertility issues in approximately 40 percent of cases. For men, infertility can be caused by conditions that affect the formation and transport of sperm, making it more difficult for the sperm to fertilize the woman’s egg. Most commonly, male factor infertility is caused by problems with the production, maturation, motility, and structure of a man’s sperm.

Sperm disorders can be the result of a slew of factors, including hormonal imbalances, immunological disorders, and genetic diseases. Male factor infertility can be diagnosed through tests like a semen analysis, which measures properties of the sperm such as motility, morphology, consistency, sperm count.

Fertility and Age

For both men and women, fertility naturally declines with age.

Women are born with all of the eggs her body can ever naturally produce, and that number steadily decreases over the course of the woman’s life. Before age 30, women tend to have the highest chances of getting pregnant and are the most fertile. After that, women’s fertility begins to decrease. By age 35, a a woman is 15 percent less fertile than she was at 30, and her fertility begins to decline at a more rapid pace. By age 40, her chances of conceiving are lower than her chances at age 35. One factor contributing to this lowered fertility is as the number of eggs in a woman’s ovaries decline, the eggs are more likely to have abnormal chromosomes which can make an embryo inviable.

As the number and quality of eggs continues to diminish, fertility continues to decline until the woman reaches menopause, which completely halts the ability for the woman to naturally get pregnant. The average age of menopause in the United States is 51. Other age-related factors contributing to women’s infertility can include endometriosis, uterine fibroids, and genetic abnormalities of the woman’s remaining eggs.

For men, age can diminish the amount and quality of sperm that the man produces. Other age-related factors diminishing fertility include erectile dysfunction, genetic defects in the sperm, and structural changes in the male reproductive organs.

Lifestyle and Environment

Research has consistently shown that lifestyle factors, such as diet, weight, exercise, and substance abuse can have significant effects on fertility in both men and women. Smoking, excessive alcohol abuse, radiation, and chemotherapy can significantly decrease fertility in both men and women. For women, extreme weight gain or loss, as well as excessive physical or emotional stress can also increase infertility. For men, obesity, exposure to certain medications and environmental toxins, high blood pressure, and exposure to testosterone can all contribute to infertility.

Genetics and Disease

For women, endometriosis is a common cause of infertility, possibly due to the structural and functional changes that occur in the female reproductive tract that can prevent proper release of the egg and implantation of the embryo in the uterine lining. Polycystic ovary syndrome (PCOS) is another common cause of female infertility, as it causes high hormone levels that interfere with the development and release of eggs and the formation of fluid-filled cysts within the ovaries. Women can also have primary ovarian insufficiency (POI), in which a woman stops normally producing eggs and hormones before the age of 40.

Uterine fibroids and polyps are growths that occur within the uterus that can also physically interfere with the function of the uterus and make it difficult for pregnancies to occur. Sexually transmitted infections and autoimmune disorders are known contributors to infertility as well.

If the embryo has genetic defects, such as chromosome abnormalities, this can also result in the failure of the embryo to properly implant in the uterine wall.

For men, sperm formation can also be affected by a number of conditions that cause changes in the shape or amount of sperm that is produced. Some factors include chromosome defects and genetic disorders such as Klinefelter syndrome, thyroid and hormone problems, diabetes, swelling of the testicles from sexually transmitted infections, and diabetes.

Male infertility can also be caused by the inability of sperm to be transported through the male reproductive tract. For example, this can be due to blockages in the tubes that transport sperm, or if the seminal fluid that contains the sperm becomes too thick to effectively transport the sperm.

How can we treat infertility?

Even if you or your partner are having difficulties with infertility, there are many ways we can work around these issues and increase the chances that you can have a baby. There are plenty of options to work around infertility issues occurring in both males and females, such as medication, intrauterine insemination (IUI), donor sperm, in vitro fertilization (IVF), donor eggs, and using a surrogate. Make an appointment at one of our clinics to speak with an expert about what options are right for you.

Sources:

1: https://www.cdc.gov/reproductivehealth/infertility/index.htm

2: https://www.mayoclinic.org/diseases-conditions/infertility/symptoms-causes/syc-20354317

3: https://www.nichd.nih.gov/health/topics/infertility/conditioninfo/causes/causes-female

4: https://www.nichd.nih.gov/health/topics/infertility/conditioninfo/causes/causes-male

5: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4691969/

6: https://www.columbiaurology.org/staywell/document.php?id=34439

7: https://www.fertilityiq.com/male-factor-infertility/the-semen-analysis#most-important-measurements-in-the-semen-analysis

8: https://www.nichd.nih.gov/health/topics/infertility/conditioninfo/causes/age

9: https://www.yourfertility.org.au/everyone/age

10: https://www.acog.org/patient-resources/faqs/pregnancy/having-a-baby-after-age-35-how-aging-affects-fertility-and-pregnancy

11: https://www.mayoclinic.org/diseases-conditions/menopause/symptoms-causes/syc-20353397