Egg white cervical mucus, abbreviated by EWCM on fertility charts and in fertility forums, is a phrase used to describe the most fertile kind of cervical mucus. Cervical mucus of this type looks a lot like raw egg whites, and you may notice it just for one or two days before you ovulate. It's also possible to have egg white cervical mucus for up to five days before ovulation or for just one day, though two or three days is more common.
Cervical mucus provides the ideal environment for sperm, helping them swim up from the cervix and survive the normally more acidic environment of the vagina. Your cervical mucus changes throughout your menstrual cycle. The hormones that trigger the ovaries to release an egg during ovulation also trigger other changes in your body, to help increase the chances of pregnancy.
For example, your cervix moves up higher, becomes softer, and more open just before ovulation. Also, your cervical mucus goes from a sticky consistency to a more creamy, then watery, and finally, raw egg white like consistency. Once ovulation passes, cervical mucus will dry up and return to a more sticky consistency.
For some women, cervical mucus may once again become watery or egg-white like just before menstruation. Obviously, this isn't a sign of ovulation and having sex during this time will not help you get pregnant.
Checking for Egg White Cervical Mucus
Research shows that tracking cervical mucus changes can help you time sex for pregnancy. Having sex when you notice egg white cervical mucus is ideal.
You can check your cervical mucus changes either by noticing the discharge left on your underwear, or by inserting a clean finger inside your vagina. Egg white cervical mucus will stretch a few inches between your fingers and appear to be somewhat clear and mucus-like. If you're trying to get pregnant, your chances are higher if you have sex on the days you have this very fertile cervical mucus.
It's best not to check just before or after sex, however, as sexual arousal will change your vaginal discharge. Plus, it's easy to confuse semen with watery cervical mucus. (More on checking cervical mucus.)
Lack of Egg White Cervical Mucus
Not every woman will have egg white cervical mucus, and that doesn't necessarily mean you have a fertility problem. (Though a complete lack of cervical mucus can be a sign that something isn't right.) For some women, just before ovulation, they may notice more watery cervical mucus that never quite becomes like raw egg white.
If this is your situation, then the best time to have sex to get pregnant would be the days you have this watery cervical mucus. It is possible to get pregnant and never get the so-called "ideal" egg white cervical mucus.
If you don't seem to get even watery cervical mucus throughout your cycle, you should let your doctor know, especially if you've been trying to get pregnant for awhile. A lack of cervical mucus, sometimes known as "hostile cervical mucus", can cause infertility.
Ironically, the fertility drug Clomid in higher doses can lead to a lack of egg white or watery cervical mucus.
Multiple Patches of Egg White Cervical Mucus
Normally, you should only notice egg white cervical mucus for a few days just before ovulation. Some women however may notice multiple patches of egg white cervical mucus, alternating with days of less fertile cervical mucus. This is common in women with polycystic ovarian syndrome.
Since it's not possible to know which patch of egg white cervical mucus is the one preceding ovulation in this case, you should treat each patch as potentially the "right" day to have sex to get pregnant.
Bigelow J.L., Dunson D.B., Stanford J.B., Ecochard R., Gnoth C., and Colombo B. "Mucus observations in the fertile window: a better predictor of conception than timing of intercourse."Human Reproduction. April 2004; 19(4):889-92. Epub 2004 Feb 27.
Speroff, Leon; Fritz, Marc A. (2005) Clinical Gynecologic Endocrinology & Infertility, 7th Edition. United States of America: Lippincott Williams & Wilkins.
Weschler, T. (2002). Taking Charge of Your Fertility (Revised Edition) . United States of America: HarperCollins Publishers Inc.