Ovulation is the release of an egg from your ovary into the fallopian tube. The ovulation cycle occurs in two phases. The first day of your last menstrual period starts the follicular phase, where a follicle in one of your ovaries prepares to release a mature egg. This phase can last from 7 to 40 days.
The latter part of your cycle is called the luteal phase, which takes place after ovulation. The luteal phase typically lasts from 12 to 16 days. During this time, your body prepares for the possibility of a pregnancy. The follicle in your ovary that contained the egg before ovulation changes into the corpus luteum.
The primary function of the corpus luteum is to release the hormone progesterone, which stimulates growth or thickening of the lining of your uterus. This prepares the uterus for implantation of a fertilized egg or embryo.
The luteal phase is important in the reproductive cycle. Unfortunately, some women have a short luteal phase, also known as a luteal phase defect. As a result, it becomes harder to become pregnant.
A short luteal phase is one that lasts fewer than 10 days. The hormone progesterone is essential to implantation and a successful pregnancy. When a short luteal phase occurs, the body doesn’t secrete enough progesterone, so the uterine lining doesn’t properly develop. This makes it impossible for a fertilized egg to implant in the uterus.
A short luteal phase is one cause of infertility. If you do become pregnant after ovulation, a short luteal phase can result in an early miscarriage. To sustain a healthy pregnancy, the uterine lining must be thick enough for an embryo to attach itself and develop into a baby.
A short luteal phase can also be due to failure of the corpus luteum. If the corpus luteum doesn’t secrete enough progesterone, your uterine lining may shed before a fertilized egg implants on the uterus. This occurrence can cause an earlier menstrual cycle.
A luteal phase defect can also be caused by health conditions, such as:
- endometriosis, a condition where tissue normally found inside the uterus starts to grow outside the uterus
- polycystic ovarian syndrome, a disorder that causes enlarged ovaries with small cysts
- thyroid disorders, such as an overactive or an underactive thyroid, Hashimoto’s disease, and iodine deficiency
- excessive exercise
If you have a short luteal phase, you may not realize there’s a problem. In fact, you might not suspect fertility issues until you’re unable to conceive. If you’re having difficulty getting pregnant, a doctor can investigate further to see if there’s a luteal phase defect.
Symptoms of a defect may include:
- earlier than normal menstrual cycles
- spotting in between periods
- inability to get pregnant
If you can’t get pregnant, figuring out the underlying cause is the first step to improving your odds of conception. Talk to your doctor about infertility. Your doctor can conduct a variety of tests to determine whether infertility is caused by a short luteal phase or another condition.
You’ll likely have blood tests to check your levels of the following hormones:
- follicle-stimulating hormone, a hormone released by the pituitary gland that regulates ovary function
- luteinizing hormone, the hormone that triggers ovulation
- progesterone, the hormone that stimulates growth of the uterine lining
In addition, your doctor may recommend an endometrial biopsy one or two days before an expected menstrual cycle. During this biopsy, your doctor collects a small sample of your uterine lining and examines the sample under a microscope. They can check the thickness of the lining.
Your doctor may also order a pelvic ultrasound to examine the thickness of your uterine lining. A pelvic ultrasound is an imaging test that uses sound waves to generate pictures of organs in your pelvic area, including your:
- fallopian tubes
Once you doctor identifies the underlying cause of a luteal phase defect, pregnancy may be possible. In many cases, treating the cause is key to improving fertility.
For example, if a short luteal phase results from extreme exercise or stress, decreasing your activity level and learning stress management techniques can result in the return of a normal luteal phase. Techniques to improve stress levels include:
- decreasing personal obligations
- deep breathing exercises
- moderate exercise
Your doctor may also recommend supplemental human chorionic gonadotropin, which is a pregnancy hormone. Taking this supplement can help your body secrete a higher level of the hormone progesterone.
You might also take additional progesterone supplements after ovulation. This helps your uterine lining grow to a point where it can support implantation of a fertilized egg.
Other methods to increase your chance of pregnancy include medications such as clomiphene citrate, which stimulates your ovaries to produce more follicles and release more eggs.
Not all treatments work for every woman, so you’ll have to work closely with your doctor to find the most effective medication or supplement.
Being unable to get pregnant or experiencing a miscarriage due to a short luteal phase can be frustrating and discouraging. But help is available.
It’s important that you don’t ignore fertility suspicions. The sooner you seek help from a doctor to diagnose the underlying cause, the sooner you can receive treatment and have a healthy pregnancy.
How can you tell if you’re experiencing a short luteal phase and need to seek treatment?
It’s difficult to know if you’re experiencing a shortened luteal phase as you may not have any signs or symptoms. If you’re trying to get pregnant and having difficulty, or you’re experiencing miscarriages, you should talk to your doctor to see if it’s appropriate to be tested for causes of infertility. This may include testing for a luteal phase defect.Katie Mena, MDAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.