IVF Series Part 2: How Infertility Works

Natalist’s Guide to IVF is an easy-to-understand, comprehensive explanation of IVF intended to demystify the process and empower you to take charge of your IVF journey. Here’s a sneak peek of the first chapter, How infertility works:

Generally, the medical community divides the causes of infertility under “female factors” and “male factors.” Sometimes, infertility results from a combination of female and male factors or, frustratingly, can be unexplained. 

Keep in mind that “infertility” doesn’t mean that you’re irreversibly unable to get pregnant. Many forms of infertility are treatable and reversible. Your REI will help you figure out the cause(s) of your fertility issues and offer solutions or recommendations for you and/or your partner moving forward.

Common causes of female infertility

• Weight: Being either underweight or overweight can decrease your chances of conceiving
• STIs: Some sexually transmitted infections (STIs), like gonorrhea and chlamydia, can cause scarring in the fallopian tubes, which prevents the egg from traveling down to be fertilized by sperm and increases the risk of ectopic pregnancy. [1] 
• Cigarettes:  Smoking cigarettes makes conception less likely, as it can impact both the eggs and fallopian tubes
• Toxins: Toxins such as flame retardants and dry cleaning solvents, heavy metals like mercury and arsenic, pesticides, and possibly bisphenol A (BPA) can have adverse effects on fertility and pregnancy.

2. Age: Unfortunately, one of the biggest impacts on female fertility is age, which affects women more than men. For a healthy woman in her 20s or early 30s, the chances of conceiving each month is 20% [2]. But by the time a woman is 40 years old, the chances are 10% or less each month.

3. Hormonal disorders: Ovulation is an essential part of the conception process, and hormonal conditions can cause anovulation (lack of ovulation) and infertility.

4. Structural problems: Structural causes of infertility can be thought of as physical barriers in the anatomy that can reduce the chances of pregnancy. This can include things like fibroids in the lining of the uterus (these are non-cancerous growths that can develop within the uterus), scarring of the fallopian tubes (from STIs), or scar tissue from endometriosis or previous surgeries. [3] 

Common causes of male infertility

Male factor infertility is a contributing cause of infertility in about 30-40% of hetrosexual couples [4]. Before looking at the causes of male infertility, let’s understand how doctors evaluate the health of sperm [5]:

• Semen volume: The amount of fluid expelled in the ejaculate. 
• Sperm concentration: The number of individual sperm per milliliter of semen. 
• Sperm motility: Sperm’s ability to move efficiently through the female reproductive tract. 
• Sperm morphology: The shape and size of the sperm.

Other causes of male infertility include:

• STIs: Just as with women, STIs in men can lead to fertility issues [6]
• Cigarettes: Cigarette smoking can significantly impact sperm health. Same goes for marijuana use, heavy drinking, and using illegal drugs such as heroin and cocaine. [7-8].
• Excess heat: Exposure to heat can also be harmful for sperm and has been shown to be associated with infertility [9].
• Weight: A high BMI is linked to lower sperm count and quality [8].
• Certain medications
• Strenuous physical labor

2. Age: With age, the testes tend to get smaller, and the sperm shape and movement tend to decline [8].

3. Underlying conditions: There are a number of congenital, acquired, and systemic conditions that can contribute to male infertility [8].

Halle Tecco, Natalist founder, has put together an e-book inspired by her own IVF journey with hopes of demystifying the process and empowering readers with the information they need to take charge of their IVF journey. Guide to IVF has been medically reviewed by Dr. Dana McQueen, an experienced OBGYN and reproductive endocrinologist. 

Want to keep reading? You can read the complete breakdown of each of these factors by purchasing the full e-book here, which includes even more helpful checklists, charts, tips, and expert advice. A downloadable PDF will be emailed to you after purchase. 

Preview more sections:

• IVF Series Part 1: Natalist Guide to IVF Book
• IVF Series Part 3: Overview of IVF Prep and Paperwork

Sources:

1. STDs & Infertility. Center for Disease Control and Prevention. April 11, 2023. Accessed May 2023. URL
2. Practice Committee of American Society for Reproductive Medicine in collaboration with Society for Reproductive Endocrinology and Infertility. Optimizing natural fertility: a committee opinion. Fertil Steril. 2013;100(3):631-637. doi:10.1016/j.fertnstert.2013.07.011
3. What are some possible causes of female infertility? Eunice Kennedy Shriver National Institute of Child Health and Human Development.  January 31, 2017. Accessed May 2023. URL
4. Practice Committee of the American Society for Reproductive Medicine. Diagnostic evaluation of the infertile male: a committee opinion. Fertil Steril. 2015;103(3):e18-e25. doi:10.1016/j.fertnstert.2014.12.103
5. Anawalt BD, Page, ST. Approach to the male with infertility. UpToDate. Accessed May 2023. URL
6. Goulart ACX, Farnezi HCM, França JPBM, Santos AD, Ramos MG, Penna MLF. HIV, HPV and Chlamydia trachomatis: impacts on male fertility. JBRA Assist Reprod. 2020;24(4):492-497. Published 2020 Oct 6. doi:10.5935/1518-0557.20200020
7. Harlev A, Agarwal A, Gunes SO, Shetty A, du Plessis SS. Smoking and Male Infertility: An Evidence-Based Review. World J Mens Health. 2015;33(3):143-160. doi:10.5534/wjmh.2015.33.3.143
8. What are some possible causes of male infertility? Eunice Kennedy Shriver National Institute of Child Health and Human Development.  January 31, 2017. Accessed May 2023.  URL
9. Thonneau P, Ducot B, Bujan L, Mieusset R, Spira A. Effect of male occupational heat exposure on time to pregnancy. Int J Androl. 1997;20(5):274-278. doi:10.1046/j.1365-2605.1997.d01-303.x