Luteal Phase Defect

A luteal phase defect (luteal phase deficiency) is when your uterine lining doesn’t thicken or grow enough to support a pregnancy. A thick uterine lining is necessary to grow a pregnancy. People with a luteal phase deficiency may struggle with infertility or miscarriage.


What is a luteal phase defect?

A luteal phase defect (or luteal phase deficiency) occurs when a person’s ovaries don’t produce enough progesterone after ovulation. You need to have enough progesterone for a healthy uterine lining. And you need a healthy uterine lining for pregnancy because it’s where a fertilized egg attaches and grows into a fetus. Progesterone tells your uterine lining to thicken or grow each menstrual cycle. With a luteal phase deficiency, the lack of progesterone causes the uterine lining to be less likely to carry a pregnancy.

There’s a lot of debate surrounding diagnosing and treating a luteal phase defect. Reproductive medicine organizations and providers don’t agree on diagnostic criteria or treatment for this condition. Despite this, healthcare providers agree that progesterone levels are important in pregnancy. If you’re having trouble conceiving, it’s best to schedule an appointment with a pregnancy care provider or fertility specialist.

What is the luteal phase?

The luteal phase is the part of your cycle that prepares your uterus for a potential pregnancy. It begins after ovulation and lasts until you get your period. In most people, the luteal phase lasts between 12 and 14 days.

Right before the start of the luteal phase, an egg leaves your ovary and travels through your fallopian tube. Progesterone levels rise to help prepare your uterine lining for pregnancy. If the egg becomes fertilized by sperm and travels to your uterine lining where it fertilizes, you become pregnant. If the egg isn’t fertilized by sperm and you don’t get pregnant, hormone levels drop, and you shed the thick lining of your uterus during your period.

Some people have a short luteal phase, which means their periods begin within 10 days of ovulation. Others have a long luteal phase and don’t get their periods for up 17 days or longer after ovulation.


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How does a luteal phase defect affect fertility?

A luteal phase deficiency can make it hard to get pregnant and remain pregnant. This is typically due to low progesterone levels, which affect your uterus’s ability to support a pregnancy. For instance, you may be unable to get pregnant or you may get pregnant but lose the pregnancy shortly after (miscarriage).

Researchers are debating whether the luteal phase defect causes infertility or is a symptom of infertility. Talk to your healthcare provider if you’re struggling to conceive so they can determine the best treatment for you.

What are risks of a luteal phase defect?

The two biggest risks of a luteal phase defect are infertility and miscarriage. A luteal phase deficiency prevents your uterine lining from growing thicker. A thick uterine lining creates the healthiest environment for egg implantation and fetal growth (the fertilized egg growing into a fetus).


Symptoms and Causes

What are the signs of a luteal phase defect?

Many people become aware of a problem with their luteal phases when they have difficulty getting pregnant or have miscarriages. Other symptoms of a luteal phase defect include:

  • Spotting (bleeding between periods).
  • A slow rise in basal body temperature (BBT).
  • More frequent periods or a short time between periods (less than 21 days between periods).
  • For those who track ovulation, they may notice the time from ovulation to getting a period is 10 days or less.

What causes a luteal phase defect?

Healthcare providers don’t know the exact cause of a luteal phase defect, but they do know it’s related to progesterone. It could be that your body isn’t making enough progesterone or that your uterine lining isn’t responding to progesterone. With either cause, your uterine lining doesn’t grow as it should.

People with a luteal phase defect often have short luteal phases. This means their periods start within 10 days of ovulation. Experts aren’t entirely sure why some people have shorter luteal phases than others. However, one study found that people who smoke cigarettes have shorter luteal phases than those who don’t smoke. Smoking may reduce your body’s ability to produce progesterone.

Health conditions that affect progesterone levels could increase your risk of a luteal phase defect. These include:


Diagnosis and Tests

How do you know if you have a luteal phase defect?

There isn’t one test or criteria to diagnose a luteal phase deficiency.

Your healthcare provider may recommend blood tests to check the following hormone levels:

  • Progesterone. This hormone is primarily responsible for growing your uterine lining after ovulation.
  • Follicle-stimulating hormone (FSH). This hormone causes your follicles to grow each cycle. Follicles contain your eggs.
  • Estrogen. This hormone is made by the developing follicle and causes thickening of the uterine lining before ovulation.
  • Luteinizing hormone (LH). This hormone triggers ovulation or the release of an egg from a follicle.

Your provider may also perform an ultrasound to measure your uterine lining’s thickness. The thickness of your uterine lining can indicate progesterone is low or not working properly in your body.

Management and Treatment

How do you fix a luteal phase defect?

It depends on your situation and your desires for pregnancy. If pregnancy is your goal, your healthcare provider may treat a luteal phase defect with medications like:

Other times, your provider may recommend lifestyle changes like reducing stress or reaching a healthy weight. If an underlying condition is disrupting your luteal cycle, treating that condition can often correct a luteal phase deficiency.

Do you need IVF if you have a luteal phase defect?

No, you don’t need IVF (in vitro fertilization) if you have a luteal phase defect. If you’re having trouble getting pregnant or have repeat miscarriages, your healthcare provider can help you explore the best treatment options based on your situation.

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Outlook / Prognosis

Can I get pregnant if I have a luteal phase defect?

Yes, many people with a short luteal phase, or a luteal phase deficiency, have successful pregnancies. Discuss your desires for pregnancy with your provider so they can determine the best treatment for you based on your health history.

A note from Cleveland Clinic

Talk to your healthcare provider if you think you may be experiencing low progesterone or luteal phase deficiency. Fortunately, if a luteal phase defect is contributing to infertility, there are many treatment options available to you. Your provider can work with you to determine what treatment will be best for you based on your health history and desires for pregnancy.

Medically Reviewed

Last reviewed on 12/05/2023.

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