If you’ve been trying to get pregnant without success and no obvious cause has been identified, you may be suffering from something called a ‘luteal phase defect’ (or LPD for short).
This little-known condition is the subject of much discussion in infertility forums. And that’s not surprising – although LPD is experienced by approximately 6 – 10% of women in the general population, it has been diagnosed in up to 20% of women who are struggling to conceive and up to 60% of women experiencing recurrent miscarriage.
I personally believe, that a luteal phase defect is probably the cause behind many cases of unexplained infertility.
Unfortunately, if you have the condition, it’s unlikely to be diagnosed unless you chart your fertility. Periods can occur regularly, giving the impression of a normal menstrual cycle and there are no obvious clinical signs that can be recognised by a doctor. In addition, it’s not usually picked up during standard fertility investigation.
The good news is that luteal phase defects can often be identified by charting your fertility, and once diagnosed, there are a number of therapies that can correct the problem.
Luteal phase defect – what exactly is it?
To understand what a luteal phase defect is, it helps to look at your menstrual cycle as two separate phases: the follicular phase and the luteal phase. Let’s look at these phases individually.
1. Follicular Phase
The first phase of the menstrual cycle, or follicular phase, begins on the first day of your period and ends at ovulation. This phase is concerned with the growth and development of an egg (ovum), within your ovary. The egg is contained within a kind of sac, known as a follicle. At ovulation, this follicle ruptures to release the egg from the ovary. Estrogen is the dominant reproductive hormone during this phase of the menstrual cycle.
2. Luteal phase
The second phase of the menstrual cycle, or luteal phase, begins after ovulation and ends when your next period starts. Once the egg has been released at ovulation, the empty follicle transforms into a gland called the corpus luteum.
The main function of the corpus luteum is to secrete the hormone progesterone (along with other hormones) into the bloodstream. Progesterone is the dominant reproductive hormone during this phase of the menstrual cycle.
Progesterone prepares the uterus lining to receive and nuture an embryo. In a normal menstrual cycle, progesterone is secreted for 10 – 16 days – corresponding to the lifespan of the corpus luteum.
If pregnancy does not occur, the corpus luteum eventually breaks down, and progesterone levels drop with the onset of your period. If pregnancy does occur, the corpus luteum is ‘rescued’ and continues to produce progesterone. This progesterone maintains the uterine lining and supports the developing embryo during the first few weeks of pregnancy.
The production of progesterone from the corpus luteum, and the response of the uterus lining to this progesterone is absolutely critical for the normal implantation and development of an embryo. If the production of, or response to this progesterone is faulty, this is known as a luteal phase defect.
A luteal phase defect occurs when:
- the level of progesterone secreted by the corpus luteum is too low
- progesterone is not produced by the corpus luteum for an adequate length of time
- the progesterone is produced normally, but the lining of the uterus is unable to respond appropriately
So, put simply, a luteal phase defect is a condition where the lining of the uterus fails to develop normally during the luteal phase of the menstrual cycle. This will usually prevent successful implantation and growth of an embryo.
Luteal phase defect symptoms
Symptoms that MAY indicate a luteal phase defect are:
- Difficulty getting pregnant (with no other explanation)
- Repeat early miscarriage
- Short menstrual cycles of less than 26 days (although short cycles are often perfectly normal)
- Premenstrual spotting
- Premenstrual Syndrome (PMS)
Often, apart from difficulty getting or staying pregnant, there are no symptoms at all.
Luteal phase defect – how to find out if you have one
Unfortunately, there is currently no convenient, accepted medical test available to diagnose a luteal phase defect. However, your doctor may suspect LPD if you have:
- A serum progesterone level of <30 nmol/L or < 10 ng/ml. It’s extremely important that the blood test is done approximately 7 days after ovulation (mid-luteal phase). Your day of ovulation can be worked out by charting your basal body temperature (see below).
- A short menstrual cycle of less than 26 days (this is NOT a reliable sign on its own however, as short menstrual cycles are often completely normal).
Charting your fertility
The good news is that luteal phase defects can often be identified by charting your fertility. By learning the fertility awareness method and charting your fertility, you have a powerful diagnostic tool at your disposal.
Fertility charts can identify a number of potential fertility problems, and this includes luteal phase defects – commonly in the form of a short luteal phase.
Signs on your fertility charts that can indicate a luteal phase defect and low progesterone are:
- A short luteal phase of < 10 days in length*
- Pre-menstrual spotting during the luteal phase of your cycle, particularly if it begins less than 10 days after ovulation
- A low temperature rise or non-existent temperature rise in the presence of a positive progesterone blood test (though this isn’t always a problem)
- Unstable temperatures in the luteal phase
*It’s sometimes stated that a luteal phase under 11 days in length is problematic, but this is not my experience. Many of the women I work with have a luteal phase length of 10 days and this does not usually prevent a successful pregnancy.
Your luteal phase length can be reliably measured by charting your basal body temperature and cervical fluid. However knowing how to interpret your chart correctly, is key.
Using an ovulation predictor kit (OPK) to identify your day of ovulation can also be helpful, however it’s important to note that used on their own, OPKs are not always accurate.
In the Fast Track to Pregnancy Program™ you’ll learn how to use fertility charting to recognise a luteal phase defect, and what to do if you have one. I’ll also discuss real life examples from two of my clients and how they got pregnant after discovering they had a luteal phase defect.
Luteal phase defect – how is it caused?
There are a number of different factors that can cause abnormal progesterone production and luteal phase dysfunction. LPD can be caused by:
- Certain medical conditions
- Recently stopping hormonal contraception
- Stress (both short term and long term stress)
- Being underweight
- Nutritional deficiencies/unhealthy diet
- Oxidative stress
- Low cholesterol levels
Although we don’t yet fully understand the physiology behind luteal phase defects, we do know that they are normally the result of either a defective corpus luteum or a defective endometrium (uterus lining):
Dysfunctional corpus luteum
The first (and probably most common) cause of a luteal phase defect is a dysfunctional corpus luteum. If the corpus luteum is unable to function normally, this results in an inadequate production of progesterone. There are a number of factors thought to be responsible for a dysfunctional corpus luteum:
Abnormal follicle development
The corpus luteum originates from the same cells that made up the follicle (which contained the egg) in the first part of the cycle. For this reason, abnormal follicle development tends to result in an abnormal corpus luteum. Follicle development can be compromised by a number of different factors, including nutrient deficiencies and an excess of free radicals (oxidative stress).
Abnormal hormone levels
In addition, a delicate balance of a number of different hormones is required for the normal growth and maturation of the egg follicle. An abnormality or imbalance in one or more of these hormones, can also upset the normal process of follicle development and ovulation.
Inadequate blood flow
It appears that faulty blood vessel development and inadequate blood flow also affect corpus luteum function. Research has shown that blood flow to the corpus luteum is strongly associated with progesterone levels during the luteal phase.
Abnormal response to progesterone by the uterus lining
The second key cause of luteal phase defects is a dysfunctional endometrium (uterus lining). In this situation, despite normal progesterone levels, abnormalities in the endometrium prevent it from responding appropriately to this progesterone.
Again, this results in abnormal endometrial development, which hinders the implantation and development of an embryo. More research is required to understand this process better.
Luteal phase defect treatments
If your fertility charts consistently show a short luteal phase or other signs of a luteal phase defect, don’t panic, because LPD can be corrected in many cases.
It’s important that you first see your doctor or specialist however, so that any medical conditions that might be causing the problem can be diagnosed.
Treatment of luteal phase defects can often be achieved with prescription drugs, supplements and dietary or lifestyle changes. The correct treatment for you will depend on the probable cause of the luteal phase defect.
It’s important to note, that while some supplements for treating luteal phase defect are backed by scientific research, others such as Vitamin B6 are not proven to be effective.
Correcting a luteal phase defect can often be relatively simple, though it may take a little time for your menstrual cycle to normalise and for fertility to be restored.
In Step 3 of the Fast Track to Pregnancy Program™ I discuss the causes of luteal phase defects and their associated treatments in detail. This information will help you and your doctor decide on the best treatment for you.
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