When you’re trying to conceive, it’s useful to have a basic understanding of how your cycle and your hormones work. It may sound boring to you, but in my opinion the menstrual cycle is one of the most amazing things that happens in the female body.
A typical menstrual cycle is 28 days. Day one of your cycle is the first day of menstrual flow. If your period starts in the evening, then the next day is considered day one. Not all menstrual cycles will be exactly 28 days but in my clinical practice, I do prefer that my patients’ menstrual cycles fall between the 26 to 32 day range. I use acupuncture and herbal medicine to regulate their cycles.
Menstruation occurs regularly after puberty until menopause due to the cyclical activity of the ovaries. The point of having a menstrual cycle is to prepare the body for a potential pregnancy.
The woman’s body releases a mature egg every month and this cycle is driven by hormones.
The menstrual cycle is divided into 2 phases: Follicular and Luteal Phases. Follicular Phase is Day 1 to 14 - the first half of your cycle. Luteal phase is Day 15 to 28 - the second half of your cycle.
Follicular (Estrogenic) Phase
It all begins in the hypothalamus (a gland in the brain). The hypothalamus tells the pituitary gland (which is another gland in the brain) to do its job. The pituitary releases FSH (follicle stimulating hormone) and LH (luteinizing hormone) - we will talk about LH a bit later.
FSH (follicle stimulating hormone) will cause about 15 to 20 eggs within follicles in the ovaries to start to mature. Each egg is encased within a follicle and the follicle produces estrogen. Estrogen is the hormone necessary for ovulation to happen.
The level of estrogen is at its lowest on the first day of your period but as the follicles grow, the estrogen will increase. Estrogen is important because it helps the uterine lining to build and get thicker which will be needed to provide a fertilized egg all the nutrients and support it needs for growth.
The rising estrogen also increases discharge of cervical mucus which is important if you’re trying to conceive. Cervical mucus is a slippery discharge that helps the sperm to travel into the cervix and sperm can survive in it for several days...sometimes even up to 5 days.
Follicles are fluid-filled cavities in the ovaries and each follicle contains an undeveloped egg. With the release of FSH, the follicles get bigger and bigger and produce estrogen until one follicle (called the dominant follicle) gets to be the biggest. This rise in estrogen causes a surge of LH (luteinizing hormone) - you may be familiar with the term LH Surge - this triggers the dominant follicle to rupture and release the egg. This is called ovulation and typically happens on day 14 but not necessarily exactly on day 14. It’s normal to feel some discomfort or twinges in your lower abdomen at this time (although many women don’t feel anything at all).
The rise in estrogen is what determines how long it will take for your the follicle to release the egg. It typically will occur within 8 to 21 days.
What is left of the follicle after the egg has been released is called the corpus luteum (essentially an empty follicle). This marks the end of ovulation and the beginning of the luteal phase.
The Luteal (Progestational) Phase
Once ovulation has occurred and the egg has been released, it passes through the wall of the ovary and moves through the fallopian tube towards the uterus. The egg can live for up to 24 hours.
If the egg hasn’t been fertilized, it remains alive for 24 hours and then will simply disintegrate and be reabsorbed by the body. The egg at this point is about the size of a period at the end of a sentence so obviously won’t be noticed when it comes out of the body.
The corpus luteum (the empty follicle) remains on the interior of the wall of the ovary and produces progesterone which is the main hormone involved in the luteal phase. Progesterone and estrogen continue to rise.
The Reasons For Progesterone
Progesterone is so important for a woman’s fertility! Here are three of it’s top uses:
1. Prevents the release of all other eggs for the rest of the cycle
2. Causes uterine lining to thicken and sustain itself until the corpus luteum dies about two weeks later
3. Causes the primary fertility signs to disappear including cervical fluid, waking temperatures and cervical position
In rare occasions, more than one egg is released during ovulation and this is what’s responsible for fraternal twins. Due to the powerful effect of progesterone, you won’t run the risk of more eggs being released later on say weeks or months later. The body protects that potential pregnancy by preventing the release of more eggs following ovulation.
What Happens When No Fertilization
If the egg is NOT fertilized, the corpus luteum destroys itself in about 10 to 12 days which then causes a halt in the secretion of estrogen and progesterone. When there is no longer an increased level of these hormones, the uterine lining will shed - the shedding of your uterine lining is your next menstrual period. By the end of the bleeding, the lining of the uterus is cleansed and ready for the next menstrual cycle.
What Happens After Fertilization
If the egg has been fertilized (usually occurs within a few hours of ovulation) and the fertilized egg burrows into the uterine lining, your body releases the pregnancy hormone called HCG (human chorionic gonadotropin). This hormone will send a message back to the corpus luteum (that is on the ovarian wall) and keep it alive beyond its usual lifespan of up to 16 days. The corpus luteum keeps secreting progesterone and so the lining of the uterus is maintained and not shed as the menstrual period. The lining of the uterus provides the fertilized egg a place to implant and grow into a baby. Pregnancy tests detect levels of HCG in the blood and/or urine.
Your body continues to rely on the corpus luteum for secretion of estrogen and progesterone so that the lining of the uterus is not shed until the placenta is mature enough and takes over giving the embryo all of the nutrients that it needs and maintains the pregnancy. It’s close to the end of the first trimester of a pregnancy that the placenta takes over the pregnancy and the corpus luteum dies off. The placenta will not only maintain the lining of the uterus but will also provide all the oxygen and nutrition the fetus needs to thrive.
Chinese medicine and western medicine breaks up the menstrual cycle a little differently. Where western medicine breaks it down into 2 phases - the follicular and luteal phases (as explained above) - Chinese medicine breaks it down into 4 phases and better still, has many applicable diet and lifestyle recommendations for each phase. You can read about that in my past blog post: Eating Through Your Cycle to Get Pregnant
So there you have it! That’s a brief simplified overview of what’s happening in your body every month. If you’re noticing that your periods aren’t regular (every 28 days or so), seek out a Chinese medicine doctor in your area. Regulating the menstrual cycle and enhancing fertility is an area where Chinese medicine shows its excellence and shines.
Yours in Health,