Here we'll go more into more detail on cervical mucus (CM), including what it is, why it’s important, and how learning about it may help you master your fertility.
CM is a perfectly normal substance produced by your cervix that is sometimes referred to as cervical fluid or discharge. In her groundbreaking book Taking Charge of Your Fertility, Toni Weschler says:
“…I would suggest you never again use the “d-word” to describe your healthy cervical fluid. After all, we don’t refer to men’s healthy semen as “discharge”
She draws this correlation between cervical mucus and semen because they serve the same function. Both cervical fluid and semen exist for the same very important purpose: To keep sperm alive long enough to reach and fertilize an egg, and to facilitate the sperm’s journey there as quickly and safely as possible.
4 Ways Cervical Mucus Helps Sperm
Cervical mucus is a crucial component to getting pregnant by providing:
- An alkaline environment for the sperm. A woman’s vagina is slightly acidic and hostile to sperm. Fertile cervical mucus is alkaline, like a man’s semen, and provides a safe harbor for the sperm (2).
- Sustenance for the sperm, while they swim their way on up through the cervix, to reach the egg in the fallopian tube. That’s a long way for such a small thing to swim. The sperm need food along the way, and fertile cervical fluid provides the needed nutrition.
- An easy pathway for the sperm to swim through. While infertile cervical fluid, at a microscopic level, is like brambles and weeds that trip up the hopeful sperm, fertile cervical fluid has a beautiful crystalline structure that provides perfectly shaped passageways to allow sperm to swim with the least effort, and in the right direction, to meet the egg on time for their important date.
- A filter to remove irregular sperm so only the most suitable bachelors arrive at the egg’s doorstep.
Cervical Mucus Changes Throughout Your Cycle
Cervical mucus tends to follow a predictable pattern each and every menstrual cycle.
Menstruation: Bleeding for around 3 to 7 days, though this varies from person to person (6). During this time, you may or may not observe cervical mucus, but it will likely be masked by menstrual blood (1).
None: After your period ends, you may have a few days when not a lot is going on down there. These days are often called dry days and are considered least fertile (1).
Sticky: Your cervix will start producing a sticky or pasty kind of cervical mucus. It may look like grade-school paste, or be slightly springy. It’s more of a solid kind rather than a liquid, but we still call it cervical mucus... plus, cervical paste sounds GROSS! (But what about cervical pâté? Fancy!) Whatever we call it, this type of cervical mucus means that the period of fertility has begun; this is because sperm might be able to survive in this infertile CM long enough for the fertile cervical mucus to be produced.
Creamy: As your cycle progresses, your estrogen level is rising every day and with it, the water content of your CM will also increase. (1)
Egg white: Egg white cervical mucus, sometimes abbreviated to EWCM, is so named because it resembles raw egg whites. It’s clear, slippery, and can usually stretch an inch or more. THIS is the really fertile stuff (3)! It’s alkaline and has a beautiful crystalline structure when viewed under a microscope (1). This special mucus can keep sperm alive for up to 5 days inside your body (4, 5).
Watery: Sometimes the water content of your CM might be so high that the it is more like water and doesn’t hold its shape at all. It might even slide right out of you when you're using the toilet, so if you're really carefully tracking CM, you may want to check (1). Another good sign is that very wet sensation in your vagina; it might even feel like you’ve started your period.
Ovulation: That takes us up to ovulation, at which point the egg has been released by the ovary and now we are back to a dry or sticky holding pattern until menstruation begins.
Important Note: Not everyone will observe all types of CM, and that's ok! You may not have watery or EWCM, or you may also experience multiple types of CM on the same day (7). Some may also experience fertile-quality CM late in the luteal phase, which can be a sign of a health problem or be totally normal (1). Always check with your doctor if you're ever concerned.
Now you know that it’s produced by your cervix, it helps sperm live long enough inside your vagina to reach the egg, and goes through a predictable pattern each cycle, getting wetter as you approach ovulation, and drying up after the egg is released. Need more details? Read about The Many Faces of Cervical Mucus here.
Keeping track of your own unique pattern of CM every cycle may provide a window into the state of your fertility, which you and your doctor may use to discuss and address any concerns.
- Weschler, Toni. (2015). Taking Charge of Your Fertility: The definitive Guide to Natural Birth Control, Pregnancy Achievement, and Reproductive Health.