What is corpus luteum defect?

couple talking to fertility doctor

Corpus luteum defect, also known as luteal phase defect, is a controversial topic among doctors. Some physicians believe that corpus luteum defect is a frequent cause of miscarriage in the first trimester. The corpus luteum produces progesterone which is necessary for a healthy pregnancy. If the corpus luteum is not functioning properly, it may not produce enough progesterone to sustain a pregnancy.

How Is Corpus Luteum Defect Diagnosed?

BBT Charting

There are several ways that doctors can diagnose corpus luteum defect. One way is by evaluating a woman’s bbt chart. BBT charting involves taking your temperature every morning upon waking with a basal thermometer. The progesterone produced by the corpus luteum causes a rise in temperature on your bbt chart. After you ovulate you will see higher temperatures on your chart. The first half (follicular phase) of your chart should have lower temperatures and the second half (luteal phase) should have higher temperatures. During a normal luteal phase, you will see higher temperatures for around 12-14 days. A luteal phase that is shorter than ten days may be an indicator of a corpus luteum defect. Some doctors are more conservative and may be concerned if your luteal phase is shorter than 12 days.

Endometrial Biopsy

An endometrial biopsy is used to evaluate how developed your endometrial lining (the lining of your uterus) is at a specific stage in your cycle. Endometrial biopsies are generally done towards the end of your cycle, around day 25-27 if you have a typical 28-day cycle. Your doctor will insert an instrument into your uterus and scrape off a sample of your lining for analysis. Then a pathologist will evaluate the sample and date it based on where it appears to be in development. If the date the pathologist determines is more than two days off from your actual cycle day, you may have a corpus luteum defect.

Blood Progesterone Levels

Your doctor may measure the levels of progesterone in your blood at different stages in your cycle. If your progesterone levels are low, this could be mean you have a corpus luteum defect. However, progesterone levels can fluctuate throughout the day. For example, your progesterone level in the morning might be significantly different than in the afternoon. Consequently, measuring blood progesterone levels is not the most reliable way to diagnose corpus luteum defect.

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Treatment of Corpus Luteum Defect

Progesterone Supplements

There are a few ways doctors treat corpus luteum defect. Your doctor might prescribe progesterone supplements. Progesterone supplements can be given in pills, shots, or vaginal suppositories. Progesterone treatment is generally started a few days after ovulation and continued for the first twelve weeks of pregnancy. Not all doctors prescribe progesterone supplements for corpus luteum defect.

Progesterone treatment is controversial. There aren’t any known birth defects related to progesterone use, but we do not have long term data on it. At one point, DES was used to prevent miscarriage. It wasn’t discovered until years later when the children of women who took DES started having fertility issues, reproductive tract abnormalities, and cancer of the vagina and cervix. This is one reason why many doctors are hesitant to prescribe progesterone supplements.

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Clomid (Clomiphene citrate)

Another way that doctors treat corpus luteum defect is by using fertility drugs like Clomid. Clomid works by stimulating your follicles to ripen and mature. The follicle eventually becomes the corpus luteum. Stimulating the follicles in the first half of the cycle improves the quality of the follicle and in turn, improves the quality of the corpus luteum. With a healthier corpus luteum, more progesterone is produced during the luteal phase.

HCG Injections

Some doctors give injections of HCG to treat corpus luteum defect. HCG maintains the corpus luteum. HCG injections help to stimulate the corpus luteum which results in higher progesterone production.