The scheme of events in a typical menstrual cycle involves follicle maturation, ovulation and luteal phase wherein the uterine lining is prepared for embryo implantation. The simplest definition of the luteal phase is “the last 12-14 days of the menstrual cycle” before the onset of periods. A successful pregnancy requires a healthy start and endometrium provides the first life support to the developing embryo. A thin insufficiently developed or early disintegrating endometrial lining leads to unsuccessful implantation seen as an early miscarriage. Progesterone also is known as gestation hormone is the key hormone involved in preparing a good three-layered endometrial lining considered optimal for embryo implantation. Low progesterone levels make up a thin endometrial lining that leads to spotting in between periods and shorter cycles. The medical community, unfortunately, does not have a consensus on the fact that inadequate progesterone levels contribute to recurrent miscarriages, however, it is generally observed that low progesterone levels do pose problems in getting pregnant.
Tests to detect Luteal phase defect syndrome are:
progesterone levels during the luteal phase
studying the endometrial lining by ultrasound and biopsy 
checking beta 3 integrin levels  and
FSH and LH hormonal levels
Luteal phase defect symptoms:
Short cycles – Luteal phase of fewer than 10 days – generally detected in monitored cycles when the patient knows when she ovulated
Low progesterone levels
Spotting in between periods – light bleeding as endometrial lining sheds
Difficulty in getting pregnant
An important note of caution here is that only when these symptoms are experienced for three successive cycles are you suspected to be having a luteal phase defect.
What causes the Luteal phase defect?
Low progesterone levels
The levels of progesterone peak during the luteal phase in a normal cycle to prepare a cushiony endometrial lining for the embryo. Lower levels of progesterone lead to thin endometrial lining insufficient for embryo implantation and support during the initial pregnancy period.
Menstrual cycles that do not make mature follicles are called anovulatory cycles. The maturing follicles also produce progesterone and in absence of follicles, the natural progesterone levels decline.
Defective thyroid function
Thyroid hormone makes the precursor of progesterone and lower levels of thyroid lead to lower levels of progesterone.
Stress induces production of “ stress hormone” (cortisol), this, in turn, suppresses progesterone production
How to correct luteal phase defect?
If you are diagnosed with a luteal phase problem, there are several steps you may want to explore before relying on the conventional medical treatment of Clomid, HCG injections, progesterone injections, pills or suppositories
What can you do?
Vitamin B 6
Vit B 6 also helps to increase progesterone levels. Suggested usage is 50mg up to 100mg daily. Make sure to use B6 in conjunction with a B complex or multivitamin as all the Vitamin B’s work synergistically.
Progesterone “opposes” oestrogen, which means by lowering oestrogen, your body will produce more progesterone, which is required to lengthen the luteal phase. A study found that reducing the sugar by 60%, it decreases estrogen by 25% within 3 weeks.
Incorporating nuts, green leafy vegetables, foods rich in vitamin C and essential fatty acids will promote hormone balance and manage luteal phase defect.
What can Natural Fertility Australia do?
We can help you to balance your hormones naturally by making sure your estrogen and progesterone are working in perfect synergy. We are not prescribing synthetic or natural hormones to achieve this. This is done by taking natural medicines to stimulate your body to release the correct amount of hormones.
References http://www.sart.org/uploadedFiles/ASRM_Content/News_and_Publications/Practice_Guidelines/Committee_Opinions/Luteal%20phase%20deficiency2012noprint.pdf https://recurrentearlymiscarriage.wordpress.com/category/beta-3-integrin/