For those interested in Chinese medicine:
"The Uterus has to provide a hospitable environment for the developing embryo. There has to be sufficient warmth and nutrition available for proper growth and development. If conception has occurred, the embryo has less than a week to implant into the uterus. Implantation into the uterus provides a direct link to blood vessels, which supply vital nutrients to the developing embryo. This link has to be maintained until the placenta is formed at about 3 months into the pregnancy. The Uterus has to be able to support the development of the fetus directly in the beginning and then by supporting the placenta for the rest of the entire pregnancy. Any weakness in the Uterus will result in miscarriage (spontaneous abortion) of the fetus. But first the Uterus has to be able to allow for implantation to occur. A very common cause of Infertility of modern women is invasion of Cold into the Uterus. Modern American women have a fondness for cold drinks and cold foods. We are a Nation of people who put ice into every thing we drink. Even if we live in warm climates, we can still be exposed to Cold pathogens, even in summer! This happens quite frequently because Americans don't like to sweat or to be hot. If we are outside in the summer months and work up a sweat what do we do? Jump into a swimming pool, go into air-conditioned cars or houses, drink cold drinks immediately subject our bodies to extremes of temperature. If we are sweating, our pores are open and our body is cooling down naturally. If we enter into the Cold or drink Cold drinks, our pores will slam shut trapping moisture under the skin. ( This leads to other problems discussed elsewhere). However, if a woman is menstruating, a channel has been opened directly into her womb. Cold has an easier time entering the body and going deep inside. Cold that invades the womb, will prevent an embryo from implanting or remaining the time needed to fully develop. Even though fertilization may occur, a pregnancy won't come to term. A woman usually can tell when she has Cold in the Uterus because heat feels very good when pressed against her abdomen. This can be heating pads or hot baths. She might also have a craving for hot drinks.
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A condition known as a "cold uterus" means that the uterine lining has not responded appropriately to the warming hormone (progesterone). The vessels which supply blood to the uterus are constricted as a result of this "cold" response. Women with this diagnosis often have a combination of patterns of kidney yang (the warming energy) vacuity and blood stasis. They will often have premenstrual low back pain, cramps which respond to heating pads, and clotty menstrual blood. Prescribing warming herbs and invigorating the blood will help resolve this pattern.
Monitoring the basal body temperature gives immense information regarding where the imbalance occurs as well. Temperatures which exhibit no biphasic pattern at all and are relatively low (around 97 degrees Fahrenheit) and are accompanied by cold signs reveal a diagnostic pattern of kidney yang vacuity. Remedy: supplement kidney yang. A biphasic, ovulatory pattern will begin to emerge, and reproductive hormones respond accordingly. A monophasic pattern of high temperatures which are accompanied by heat signs will respond to yin supplementation and clearing of vacuity heat.
A sawtooth, erratic pattern of temperatures means there is not enough hormonal regulation occurring to normalize the temperatures. Most often this will be accompanied by symptoms of liver depression qi stagnation, a pattern which occurs as a result of maladaptation to stress. Women who exhibit no pattern at all to their menstrual cycles often have liver qi stagnation as well. One month the cycle may last 35 days, and the next month it is 26 days. There are severe premenstrual signs some months, and other months there are almost none. The problem most assuredly lies in the liver qi (i.e., stress.) and its associated endocrine effects, and the remedy will be to course the liver and rectify the qi."