The luteal phase is one of the menstrual cycle phases that lasts from day 14 to day 28. Various hormonal and uterine changes characterize the luteal phase. These changes include increased levels of progesterone, estrogen, luteinizing hormone, follicle-stimulating hormone, altered endometrial lining, dysfunction of the corpus luteum, etc. In addition, luteal phase defects can occur due to various physiologic and pathological causes, including anorexia, obesity, endometriosis, significant weight loss, polycystic ovary syndrome, advanced reproductive age, etc.

What Is Luteal Phase?

The luteal phase is one of the phases occurring during a menstrual cycle. A typical menstrual cycle (periods) is 28 days long. A menstrual cycle starts with the follicular phase, which extends from day 1 to day 14, followed by ovulation which is usually around day 14. Lastly, the cycle ends with the luteal phase, which begins after ovulation and ends on day 28. The luteal phase usually lasts for 14 days. The luteal phase is a dynamic phase characterized by various hormonal and uterine changes (changes in the uterus). These changes include:

Change in levels of various hormones.
Increased progesterone levels.
Increased estrogen levels.
Decreased luteinizing hormone levels.
Decreased follicle-stimulating hormone levels.
Alterations in the endometrial lining to support egg implantation.
Development of a temporary endocrine structure in female ovaries known as the corpus luteum.

Change in the levels of hormones during the luteal phase cause several symptoms that are generally known as premenstrual syndrome (PMS). The symptoms include; mood swings, anxiety, headaches, irritability, tender breasts, bloating, food cravings, altered sexual desires, etc.

What Is a Luteal Phase Dysfunction?

Luteal phase dysfunction or luteal phase defect refers to disorders resulting from impaired corpus luteum function associated with insufficient progesterone synthesis. Recurrent pregnancy losses and infertility have both been linked to luteal phase dysfunctions. In the case of an individual with luteal phase dysfunction, the uterine lining does not grow properly every month, and decreased progesterone production results in fertility issues. Given the significance of the luteal phase in the development of a healthy pregnancy, a defect in the luteal phase has been proposed as a cause of recurrent pregnancy loss. Typically, a luteal phase shorter than ten days is known to occur in the case of luteal phase dysfunction (other definitions include less than 11 days and less than nine days).

What Causes Luteal Phase Dysfunction?

The common causes of luteal phase dysfunction include:

Eating disorders or amenorrhea.
Endometriosis (growth of endometrial tissues outside the uterus).
Excessive exercise and physical stress.
Significant weight loss.
Stress.
Obesity.
Polycystic ovary syndrome (enlargement of ovaries with the presence of small cysts on the outer edge).
Aging.
21-hydroxylase deficiency.
Thyroid dysfunction.
Hyperprolactinemia (excessive levels of the hormone that produces breast milk).

Is Luteal Phase Dysfunction a Common Condition?

Although it is difficult to pinpoint the exact incidence, three to four percent of infertile couples may be affected by the condition.
Moreover, healthy women occasionally and randomly produce less progesterone during the luteal phase.
Women of all races are affected by luteal phase deficit. Luteal phase insufficiency is prevalent in women in their reproductive years.

What Are the Symptoms of Luteal Phase Dysfunction?

Common symptoms of luteal phase dysfunction:

Frequent periods.
Frequent miscarriages.
Difficulty in conceiving.
Spotting between periods.
Enlargement of the thyroid gland may be an indication of hypothyroidism.
An enlarged, atypically shaped uterus indicates myomas of the uterus.

What Are the Other Diseases Associated With Luteal Phase Dysfunction?

Some other common conditions similar to luteal phase dysfunction are:

Hyperprolactinemia: An endocrine disorder characterized by excessive production of prolactin hormone. It is the hormone responsible for milk production in breasts.
Polycystic Ovarian Syndrome: A hormonal condition known as the polycystic ovarian syndrome is prevalent in females of reproductive age. Women with the polycystic ovarian syndrome may experience irregular or prolonged menstrual cycles or have elevated amounts of androgens. The ovaries could produce a lot of tiny cysts on the outer lining of the ovary.
Thyroid Diseases: Imbalance in the levels of the thyroid hormones (thyroxine, triiodothyronine, and calcitonin) may lead to several thyroid gland disorders like hypothyroidism, hyperthyroidism, goiter, etc.

How Is Luteal Phase Dysfunction Diagnosed?

Luteal phase dysfunction or luteal phase defects are typically hard to diagnose because numerous blood examinations confirm the diagnosis. A clinical diagnosis of luteal phase dysfunction is obtained by multiple diagnostic procedures, including clinical, biochemical, and histologic testing.

Blood Examinations: Blood tests are done to check the levels of the follicle-stimulating hormone, luteinizing hormone, progesterone, estrogen, etc.
Imaging Tests: A pelvic ultrasound may be done to check the thickness of the uterus lining and other abnormalities associated with the uterus.
Endometrial Biopsy: This method was earlier used to diagnose luteal phase dysfunction. Endometrial biopsy is not advised for histologic dating of the endometrium, according to the American Society for Reproductive Medicine and the Society for Reproductive Endocrinology and Infertility. Endometrial biopsies have not been demonstrated to distinguish between fertile and infertile women; instead, they have the accuracy in discerning only the early, mid, and late luteal phases.

How Is Luteal Phase Dysfunction Treated?

Luteal phase dysfunction requires treatment depending on the person's general health and whether they are trying to get pregnant. In addition, the condition will require treatment of other health problems that may be leading to luteal phase dysfunction. Medications for luteal phase dysfunction include:

Elevated serum prolactin levels have been treated with dopamine receptor agonists.
Hypothyroidism is treated by thyroid replacement therapy.
The decreased levels in the luteal phase seen with this condition are raised by supplemental progesterone.
Clomiphene citrate improves follicular development and increases progesterone levels during the luteal phase.
Human menopausal gonadotropins increase follicular development and progesterone levels during the luteal phase.

Conclusion

A luteal phase deficiency may develop if the ovaries do not release enough progesterone or the uterine lining does not react to the hormone. Anorexia and endometriosis, among other health issues, have been associated with the condition. In addition, a luteal phase deficiency prevents the creation of the uterine lining, which is necessary for egg implantation and fetal development and is characterized by low progesterone levels. Thankfully, luteal phase defect is easily detectable and treatable with progesterone-supporting medications or lifestyle modifications.