What happens in the second phase of the cycle
After ovulation, at the site of the burst follicle, a corpus luteum is formed - a temporary gland that produces progesterone. Under its influence, the uterine mucosa becomes loose and nutritious, ready to receive an embryo. Normally, the second phase lasts about two weeks. If the corpus luteum is poorly formed or does not work enough, there is little progesterone, the mucous membrane does not mature completely, and the phase is shortened. Key point: the quality of the corpus luteum is established in the first half of the cycle, when the follicle matures, so you need to look for the cause before ovulation.
- Shortening of the second phase to less than 11–12 days
- Insufficient progesterone production
- Defective maturation of the uterine mucosa
- Incomplete ovulation or its absence
- Impaired mucosal sensitivity to progesterone
Reasons
Isolated insufficiency of the corpus luteum is rare, usually a consequence of a failure in the regulation of the cycle. Common causes are increased prolactin, thyroid dysfunction, polycystic ovary syndrome, and decreased ovarian reserve in late reproductive age. Lifestyle and weight have a significant impact: strict diets, sudden weight loss, deficiency of adipose tissue, intense sports activities, chronic stress and lack of sleep suppress the production of pituitary hormones. Separately, chronic inflammation of the uterine mucosa is considered, when there is enough progesterone, but the tissue responds poorly to it.
- Elevated prolactin
- Hypothyroidism and other thyroid diseases
- Polycystic ovary syndrome
- Decreased ovarian reserve
- Sudden weight loss and low weight
- Excessive exercise
- Chronic stress and lack of sleep
- Chronic endometritis
- Obesity and insulin resistance
Symptoms
The complaints are nonspecific, and a diagnosis cannot be made based on them alone. Most often, a woman notices that the cycle has become shorter, and 3-5 days before menstruation, brownish spotting appears. Some note an increase in premenstrual symptoms: breast engorgement, irritability, swelling, headaches. When measuring basal temperature, the second phase turns out to be short or the temperature does not rise enough, although this method itself is considered outdated and inaccurate. The main reason for examination is not sensations, but difficulties with the onset and carrying of pregnancy.
- Shortening the cycle
- Spotting before menstruation
- Increased premenstrual symptoms
- Soreness and engorgement of the mammary glands
- Short second phase based on basal temperature
- Difficulty conceiving
- Early pregnancy losses
How to examine
The first thing the doctor does is confirm the very fact of full ovulation. To do this, folliculometry is used: a series of ultrasound studies showing the growth of the follicle, the moment of ovulation and the formation of the corpus luteum. Progesterone is measured about a week after ovulation, and not on a fixed day of the cycle, otherwise the result can be easily underestimated. A single value is not very informative due to the pulsating secretion of the hormone. At the same time, they are looking for the cause: checking prolactin, TSH, assessing the condition of the uterus, and if chronic inflammation is suspected, a biopsy of the mucous membrane is performed.
- Folliculometry to confirm ovulation
- Progesterone 6–8 days after ovulation
- Ultrasound of the uterus and ovaries with assessment of the mucous membrane
- Prolactin and TSH
- FSH, LH, estradiol, AMG according to indications
- Ovulation tests as an auxiliary method
- Pipelle biopsy of the uterine mucosa for suspected endometritis
- Assessment of weight, diet and exercise
What helps
You need to treat the cause, not the number in the analysis. If elevated prolactin, hypothyroidism or polycystic ovary syndrome are detected, their correction restores the normal second phase. Simple things play a huge role: returning to a normal weight, sufficient caloric intake, moderation in training, sleep and stress reduction. Progesterone preparations are prescribed for specific indications - in preparation for embryo transfer, after stimulation of ovulation, in case of recurrent miscarriage. It is not recommended to prescribe them to everyone “for prevention”: this does not replace the search for the cause.
- Treatment of the underlying disease
- Normalization of body weight in both directions
- Moderate physical activity instead of strenuous exercise
- Eating well and getting enough sleep
- Correction of thyroid function
- Decrease in prolactin when it increases
- Progesterone preparations strictly according to doctor's indications
- Treatment of chronic endometritis
- Stimulation of ovulation in case of its violation
