Randine Lewis, Ph.D., Lic.Ac.
The luteal phase of the menstrual cycle spans from ovulation at mid-cycle until menstruation. The luteal phase should last for at least 12 to 14 days. A luteal phase which is less than 10 days will have difficulty producing an environment favorable for implantation.
The luteal phase derives its name from the fact that the luteinized cells from the collapsed follicle undergo a structural transformation in response to increased vascularization, a process known as luteinization. Thereafter these two cell types produce progesterone; one of which is dependent on the secretion of luteinizing hormone. Progesterone is secreted to prepare the uterine lining for implantation. The ovary also secretes other hormones as well – inhibin, relaxin, and 17-hydroxyprogesterone.
The endometrium, meanwhile, under the influence of estrogen during the proliferative phase, develops progesterone receptors. Progesterone then causes the uterine lining to become secretory in nature. The most important aspect here is that there is a window of implantation, where certain proteins appear on the epithelial cells of the endometrial lining and then disappear. When they are gone, the period of endometrial receptivity has passed. If these factors are not present, implantation will not occur. Many factors affect this window of implantation. Mucinous substances are secreted by glands within the endometrium during this same time period in women without implantation problems. These factors cannot be effectively treated with just a pill or hormonal supplementation. A biopsy may reveal the presence of these defects, but doesn’t tell us how it occurred, why it happened, or what do do about it.
When a pregnancy occurs, and the developing blastocyst burrows into the uterine lining, the embryo will secrete hCG, which stimulates the ovary to produce more progesterone. This process is called luteal rescue. If this process happens too late or if pregnancy does not occur, LH stimulation decreases, progesterone levels decrease and uterine prostaglandins are released. This causes the corpus luteum to shrivel. The uterine lining, because of lack of progesterone stimulation, is shed.
This series of events begins not in the luteal or secretory phase but in the follicular or proliferative phase, early in the cycle. This synchronized process is orchestrated by all of the reproductive hormones, and each of the factors necessary for implantation, known and unknown, are initiated by another process. No event in reproductive medicine is an isolated occurrence, but as with all other physiologic processes, each event is interdependent on the proper workings of the entire reproductive system. This much we know about the immediate state of the endometrium. There is much more which we don’t know, which includes the hormonal relationships, stress effects, and underlying pathological imbalances. This is where other modalities of healing can reveal their striking impact.
Most infertility specialists consider a luteal phase defect to be an insufficiency of progesterone production. This is certainly a major aspect of this dysfunction; however, if this were the only element to consider, the administration of exogenous progesterone would cure the defect. Anyone who has been diagnosed with this defect and treated with progesterone realizes the immense frustration in trying to treat this deficiency. Some studies have also demonstrated impaired folliculogenesis in women with luteal phase defects, and surely luteal phase defects indicate defective follicular development; other studies have implicated impairment in the levels of FSH or LH to be causative. They probably all play a role in different degrees in each individual woman with this presentation.
Luteal phase defect also includes a definition that the events signaling endometrial development are out of sync with the rest of the hormonal cycle, and the uterine lining actually lags behind the hormonal queues. Therefore if an egg was released and fertilized, the blastocyst would find the endometrium unreceptive for implantation, and it would pass on through undetected.
It is generally agreed upon that progesterone has a hyperthermal effect, which raises the basal body temperature at least four-tenths of one degree to one full degree farenheit after ovulation. The temperatures and thus the progesterone levels should remain elevated for fourteen days after ovulation. Progesterone levels peak during the middle of the luteal phase, about one week after ovulation. If the corpus luteum is not producing adequate quantities of progesterone, or if the uterine lining is not properly prepared for the role of progesterone, spotting may occur, the basal body temperature may drop, or the period may come early.
The Eastern View
Shifting to an Eastern paradigm and using the basal body temperature chart as a prototype of the hormonal system, Phase I is the menstrual, blood, or zero (hormonal resting) stage. Phase II is the follicular, estrogen dominated yin stage. During the ovulatory stage, yin reaches its apogee and transforms into yang, only if qi, blood, yin and yang are optimally functioning. Phase III is the luteal phase, governed by the yang hormone progesterone. This phase can thrive only if the previous phases have fulfilled their particular roles.
Most luteal phase defects include a diagnosis of low progesterone. Since this hormone is governed by the kidney yang and the spleen qi, these two elements almost always need supplementation.
However, Chinese medicine views this process beyond what is happening in the immediate luteal phase. The other phases need to be in harmony; adequate substrate needs to be present; and no obstruction – mechanical, anatomical or energetic, may be present if the luteal phase is to be in sync. Hence, there can be many reasons for luteal phase insufficiency: not enough yin to transform into yang, obstructed blood, liver qi stagnation, or not enough kidney yang or spleen qi the hold the luteal phase. This is where the correct pattern discrimination makes the difference in treatment outcome.
Most often the basal body temperature chart will reveal the manifestation of the disharmony during the luteal phase temperature.
For instance, in one form of luteal phase insufficiency, the temperatures may go along during the follicular phase as normal, the fertile cervical fluid appears, and in all appearance ovulation has occurred. The fertility monitor says ovulation has occurred. However, the temperatures do not rise dramatically. The woman might be particularly fatigued around