If you ever watched the Robin Williams movie “Patch Adams,” you might recall the hilariously awkward scene where Williams/Adams creates a giant model of a woman’s legs in stirrups with a banner reading “At Your Cervix” to welcome a group of OB/GYNs to his medical school. And if you had a sex ed class in high school, you probably learned that the sexually transmitted infection (STI) human papillomavirus (HPV) is the leading cause of cervical cancer. But what is the cervix, and what are its main functions? In this next installment in our FAM Basics series, we cover what you need to know about the cervix, cervical functioning, and how to protect your cervical health.
What is the Cervix?
According to the National Cancer Institute, the cervix is “the lower, narrow end of the uterus that forms a canal between the uterus and vagina.” Whether you’ve ever been pregnant or not, you probably already know that the cervix shortens, thins, and dilates, or opens, during the labor and delivery process so that a baby can pass through and be born. You can picture it a bit like a turtleneck that gets stretched and scrunched to go over a person’s head, only it’s the baby’s head that’s going through.
You might also wonder if the cervix opens at any other time, and the answer is ‘yes.’ The cervix opens just about as wide as a tiny slit during menstruation, when the endometrium of the uterus sheds, and again right around ovulation to potentially allow sperm to travel up from the vagina to the uterus and beyond to fertilize the newly-released egg.
But if you’re not pregnant (or trying to get pregnant), why should you care about what the cervix is and does? Little things called cervical crypts are relevant no matter whether you are trying to conceive or avoid pregnancy, or simply seeking to monitor your gynecological health.
The cervical crypts look like little pockets lining the sides of the cervix, and their main function is to produce cervical fluid, also known as cervical mucus. Cervical mucus comes out of the vagina, and a woman trained in a fertility awareness method can observe its characteristics. Cervical mucus observations are a standard of most modern, evidence-based methods of fertility awareness for good reason, because cyclical changes in the amount, consistency, and appearance of cervical mucus correspond predictably with periods of fertility and infertility.
Cervical mucus is typically thick and inhospitable to sperm after menstruation and after ovulation. This thicker mucus helps “seal off” the cervix, and protect it from things like infection. The mucus thins and becomes stretchy and clear in the days leading up to ovulation, and for a day or two after ovulation. This clear, or “egg white cervical mucus” (EWCM) as it is called (because, well, it looks a lot like egg-whites!), lets sperm through on its way up to meet the egg for fertilization.
A woman trained in a fertility awareness method, or FAM, can determine when she is and is not fertile based on her cervical mucus observations. Some methods utilize cervical mucus observations only, while others have a second fertility biomarker crosscheck, such as basal body temperature measurements or urinary hormone metabolite level testing (as with Proov strips or the ClearBlue fertility monitor). And because the cervix opens a tiny bit and moves higher up in the pelvic cavity around the time of ovulation, some methods include internal cervical os (opening) checks as well.
What do the cervical crypts have to do with infertility, and how might hormonal birth control be implicated?
As Natural Womanhood has discussed previously, the three necessary ingredients for successful conception are sperm, an egg, and fertile mucus—not just a sperm and an egg, as so many of us are taught in high school sex ed. Fertile mucus guides sperm all the way up from the vagina, through the cervix and the uterus, and into the Fallopian tubes where fertilization of the egg can take place. Good quality, fertile mucus is more than a guide for sperm though; its more-basic pH keeps the natural acidity of the vagina from destroying the sperm, and it also filters out poor quality sperm.
Inadequate or absent cervical mucus production is a direct cause of infertility, since without good quality mucus, the sperm will never survive the arduous trip to meet the egg. In fact, an absence of cervical mucus could signal that a woman is not ovulating at all, which is worth a deep dive from a medical professional trained in restorative reproductive medicine, since ovulation is a sign of the overall health of a woman’s body.
Some women who discontinue hormonal birth control find that their fertility does not return for up to a year, even though they are having sex regularly and seeking to become pregnant. There are several reasons why this might be the case. First, the pill’s hormonal mechanism of action continuously thickens cervical mucus, making it naturally hostile to sperm, and it may take some time for the body to resume normal hormonal signaling leading to adequate estrogen levels to make fertile, egg-white cervical mucus (EWCM). And if the woman went on hormonal birth control for reproductive issues such as irregular cycles in the first place, the Pill only placed a band-aid over those underlying problems, and she ends up right back where she started when she comes off it.
Additionally, some research suggests a possible association between long-term (5+ years) hormonal contraceptive use and thinning of the endometrium, or uterine lining. Even if ovulation were occurring and EWCM were present, a thinned endometrial lining would likely be inhospitable to a newly conceived embryo, leading to a very early miscarriage, sometimes called a “chemical pregnancy.”
The work of a twentieth century Swedish professor and researcher, Dr. Eric Odeblad, has contributed substantially to what we now know about cervical mucus. Dr. Odeblad collected observations from women in various stages of their reproductive life and some women were followed for over 35 years. Hormonal contraception prematurely ages the cervix by significantly decreasing S-crypts, a type of cervical crypt more abundant in younger women, which produces the ideal type of cervical mucus necessary for conception to occur; namely, mucus that provides safe passage for, transport of, and nourishment to sperm [1]. He also showed how pregnancy rejuvenates these crypts. (More recent data even shows that this accelerated maturational process causes women to have a higher susceptibility to HPV infection [2].)
How can I protect my cervical health?
One way to protect your cervical health is to avoid the use of oral contraceptives altogether, since the National Cancer Institute has found that use of oral contraceptives increases a woman’s risk for cervical cancer. Specifically:
“Women who have used oral contraceptives for 5 or more years have a higher risk of cervical cancer than women who have never used oral contraceptives. The longer a woman uses oral contraceptives, the greater the increase in her risk of cervical cancer. One study found a 10% increased risk for less than 5 years of use, a 60% increased risk with 5–9 years of use, and a doubling of the risk with 10 or more years of use (9). However, the risk of cervical cancer has been found to decline over time after women stop using oral contraceptives (10–12).”
Besides avoiding or discontinuing oral contraceptive use, one positive action you can take to protect your cervical health is learning to chart with a fertility awareness method, or FAM. Remember, EWCM is directly connected to ovulation, and ovulation is a sign of overall health in the body. Learning to effectively identify your cervical mucus, then, leads you to become aware of what’s going on inside your body, and to advocate for your reproductive and overall health as needed.
Why might hormonal contraceptive use be harmful to the cervical health of young women?
As Cassondra Moriarty previously wrote for Natural Womanhood in her article “Reasons Women Need Periods: The Role of the Menstrual Cycle in the Immune System:”
“The female fertility cycle (which doesn’t begin until puberty) plays a major role in cervical maturation. The exposure to cyclical immunity and hormonal fluctuations from the fertility cycle allows the cervix to undergo proper epithelial development, and develop a natural resistance to infection. Therefore, a cervix that has matured under these natural hormonal processes is pretty good at fighting off infections like human papillomavirus, also known as HPV.”
Conversely, a cervix that is not exposed to cyclical immunity and endogenous hormonal fluctuations could logically be more susceptible to infection, as some research indeed suggests. (More on how contraceptive use could even lead to increased susceptibility to systemic infection here.) The epidemic of sexually transmitted infections (STIs) among young people would certainly seem to support this idea, especially given that while young people nowadays are having less sex than in previous years they have significantly higher rates of STIs.
The World Health Organization says “Nearly all cases of cervical cancer can be attributable to HPV infection” (emphasis added). If hormonal birth control use predisposes young women to HPV infection, and cervical cancer is almost always connected to HPV, the known increased risk of cervical cancer among oral contraceptive users makes perfect, and disturbing, sense.
We know that cervical health is directly connected to overall health in the body, and that hormonal contraceptives do young women, in particular, very few favors when it comes to their increased risk of STIs and cervical cancer. On the other hand, women who chart fertility awareness methods, whether for health monitoring or in relation to pregnancy intention, both safeguard their cervical health and have a “leg up” (pardon the pun!) on knowing when something is wrong.
If you want more girls and women to be aware of the connections between cervical cancer and hormonal birth control use, please sign and share our FDA petition today.
References:
[1] and [2] Recent advances on the cervicovaginal secretion from adolescence to menopause: Physiopathology and implications for NFP. For a responsible transmission of life. Proceedings from IV Internation Congress for the family of Africa and Europe. Ed. Al Cappella 1988 145-157.Additional Reading:
Reasons Women Need Periods: The Role of the Menstrual Cycle in the Immune System
It was disappointing not to read in this article about the changes in the cervix before and after ovulation . Dr. Edward Keefe of New York City taught the internal mucus signs to his patients, and they raved about the changes they observed in the cervix, how helpful the cervix changes were to them. Briefly, before ovulation, the mouth of the cervix becomes softer, opens and rises. After ovulation, these signs are reversed. Some NFP groups, like NFP International, continue to teach the cervix sign.