The luteal phase is the second half of the menstrual cycle that occurs after ovulation and before menstruation. This phase is when progesterone production is at its highest and when the uterine lining is preparing for embryonic implantation. The normal length of this phase is ideally 12 to 14 days. A LPD is a hormonal imbalance that affects ovulation and the uterine lining. It is said to occur when the luteal phase is less than 10 days, progesterone production is too low, the uterine lining is unresponsive, or there is poor follicle production.

In most cases, a woman’s Hypothalamus-Pituitary-Ovarian axis is out of balance which can cause an imbalance of hormone production. One such hormone is follice stimulating hormone (FSH) which directly affects the production of follicles each menstrual cycle. When a woman produces an abnormal level of FSH, or her ovaries do not respond strongly to the FSH, it results in poor follicle development. This inadequate follicle development then leads to poor corpus luteum development. (The corpus luteum is the lining around a follicle that remains in the ovary after ovulation and secretes oestrogens and progesterone, which are steroid hormones responsible for the thickening of the trium endometrium). When there is poor corpus luteum development, the production of progesterone is inadequate and fails to properly thicken the uterine lining for implantation of a fertilized egg. The result can be infertility.

In other cases, premature failure of the corpus luteum can occur even when the initial quality of the follicle/corpus luteum is adequate but it does not last as long as it should. Failure of the uterine lining to respond can also occur even in the presence of adequate follicle development and an adequate corpus luteum. For some reason the tissue does not respond to normal levels of progesterone. Common symptoms of LPD include:

Fatigue
Breast tenderness
Feeling of internal heat
Dry eyes
Constipation
Low back pain
Shortened menstrual cycles
Low basal body temperature
Infertility
Habitual miscarriage
Bleeding between periods
Intolerance to cold