For most women there are only about 30 days in a year when there is a reasonable chance of conceiving. For a successful pregnancy to eventuate, a whole chain of events need to come together precisely in the woman’s body, in her partners body and in their relationship on one of those days. Being able to accurately identify these relatively rare opportunities raises the odds of success considerably. Watching external clues of the body provides us with a method to do exactly that.
Before we talk about these fertility ‘clues’ it is important to have a basic understanding of the menstrual cycle. Knowledge is power – so here goes.
Anatomy of Conception
Inside your vagina, if you reach deeply with your finger, you’ll feel something slightly firmer than the rest of your vagina. This firm, round protusion is your cervix, the opening of your uterus. When you put sperm into your vagina, it will swim up through your cervix and into your uterus. Your uterus is an upside-down pear-shaped organ, usually the size of an apricot, that will become the home for your baby when you are pregnant. Your uterus grows as the baby grows.
At the top of your uterus on the right and left sides is a narrow area from which the fallopian tubes branch forth. These tubes are 4-5 inches long but are extremely narrow, and they open at the ends. Floating close to the ends of each tube are your ovaries. Each ovary is about the size of an almond. Your ovaries contain all the eggs your body will ever release. Eggs mature over our lifetime, but we never create more eggs. Fertility clinics are able to test how many eggs you have left. Each month many eggs begin to mature in each ovary, each within its own follicle. When the most dominant follicle is ready and an egg within it matures, the egg is released from the ovary. Ovulation is the moment the egg bursts forth from the follicle. Following ovulation, the egg is outside the ovary in the pelvic cavity, where it’s immediately swept into the fallopian tubes by small feathery protrusion from the tubes. The egg is then guided along the tubes into the uterus.
Conception occurs after ovulation, usually inside the fallopian tubes. The egg is gently pushed through the tube, and the sperm swims into the tube via the uterus. Note that male sperm are faster swimmers and last on average 3 days whereas female sperm are slower but last up to 5days. The sperm and egg meet in the tube and if conception occurs, cell division begins and the embryo travels all the way down the tube and into the uterus, dividing cells and growing rapidly as it does. This takes a number of days. Shortly after the embryo enters the uterus, it implants into the uterine wall.
A normal menstrual cycle varies from about 24 – 35 days. For the sake of keeping this information simple we have chosen to describe a 28day menstrual cycle.
Many hormones in the brain and ovaries affect our fertility cycle. The four most important are: follicle stimulating hormone (FSH) and luteinizing hormone (LH) from the brain, and estrogen and progesterone from the ovaries.
FSH causes the egg to ripen and mature. These follicles in turn secrete estrogen. Estrogen signals the uterus to prepare its lining to receive and nourish a fetus. It simultaneously signals the cervix and cervical mucus to change and become receptive to sperm.
Mid cycle, around day 14 for many women, a sharp increase in estrogen causes a surge in LH. This hormonal dance then stimulates ovulation of the body’s ripest egg. This first part of the cycle is called the follicular phase.
After ovulation the luteal phase begins, LH signals the body to initiate the formation of the corpus luteum, which is the gland formed by the ruptured follicle following ovulation. The corpus luteum produces progesterone which causes the uterine walls to thicken. If pregnancy and implantation occur progesterone supports an early pregnancy until the placenta is formed. If egg fertilisation does not occur, progesterone levels fall, the uterus sheds its lining, and your period begins.
Let’s look at each phase in more detail.
Phase I Follicular Phase:
A dominant follicle is nutured and grows, the uterus lining develops to at least 8-10mm thick, hospitable cervical fluid is produced, the cervix opens up and discharges this wet, clear, stretchy mucus which allows sperm to survive and pass through. For optimal fertility this phase shouldn’t be shorter than 10 or longer than 17 days. (Typical is between 12-15days). If too short the egg does not have time to mature and uterine lining to thicken. If too long it may mean estrogen production is too low compromising egg quality.
Phase II Ovulation:
A series of hormones are released. The follicle, now swollen to 20mm (about the size of a grape) bursts and discharges it egg. The cervix starts to firm up and close. The egg travels down the fallopian tube.
Phase III Luteal Phase:
This should last 14days. As the egg travels through the fallopian tube, the follicle that released the egg becomes the corpus luteum, which looks like a shrivelled yellow prune. This releases progesterone hormone which is like fuel for the body’s incubator. Its purpose is to prepare the endometrium for safe implantation of a fertilised egg. The window of implantation is 5-7 days after ovulation. Your temperature should remain elevated in this phase. When a luteal phase is defect progesterone production is low.
If there is pregnancy, the embryo will release hCG (levels of which are tested via blood tests), which signals an increase production of progesterone, thus maintain a thick uterine lining for the embryo. If no hCG is produced progesterone levels drop and the uterine lining is shed.
Phase IV Premenstrual Phase:
Without fertilisation and implantation, your BBT (basal body temperature) drops and your period begins.
Phase V Menses:
This phase is considered the resting, shedding stage, and it begins on the first day of bleeding. This is the hormonal zero point, after three days the hormonal cycle begins again.
TCM Phases of a Womens Cycle
In Chinese medicine, different energies dominate each phase of the menstrual cycle:
Phase I: Kidney Yin and Blood energies govern the follicular phase. Governed by Yin energy.
Phase II: Liver Qi and Blood movement control ovulation. Pain at ovulation indicates Blood stasis, bloating indicates Liver Qi stagnation.
Phase III: Kidney Yang and Spleen Qi energies manage the luteal phase. A short or ineffective luteal phase are a result of Kid-yang and/or Sp-qi deficiency.
Phase IV: Liver Qi helps the premenstrual transformation. If these vital energies are blocked, there will be premenstrual symptoms (PMT) such as irritability, pain, constipation or diarrhea, headaches, bloating, insomnia, depression, appetite changes and so on.
Phase V: Blood is allowed to flow. Menstruation is a time of rest for all energies. The flow, amount, colour, consistency, texture and accompanied symptoms are all important indicators for the TCM practitioner.
Parallels between TCM and Western Parameters
Many of the actions of estrogen are similar to that of Yin in TCM. Likewise, progesterone is similar to the actions of Yang. The action of the pituitary hormones (FSH and LH) represent an aspect of Jing (essence).
To regulate the reproductive cycle, we work with the phases dominant energies to bring the cycle back into balance. We do this with the use of acupuncture, herbs, lifestyle and diet advise.
Now that you have a basic understanding of how the female body works, you can move onto monitoring and recording your personal fertility information. The methods we outline are highly accurate and effective in identifying your fertile days. Stay tuned for my next article.
If you would like to discuss fertility and the possible treatment options, please contact me at out Studio at Pt Chevalier, Auckland city.