What is the Luteal Phase Defect ?

Can someone please explain to me what this is, I have been hearing a bunch about it on this forum but have no idea what it is all about.

Thank you.

[Srfoshee]

Your mentral cycle is divided into two phases. The follicular phase is from the first day of AF to ovulation. The luteal phase is from ovulation to the end of your cycle. The luteal phase needs to be a certain length, if it is too short then the lining of the uterus starts to breakdown before baby has a good chance to implant. If the luteal phase is too short, it is called a luteal phase defect. A luteal phase defect is usually associated with low progesterone levels. From what I ahve read say anything below 10 days is a defect, some say it is anything below 12 days..... the "average" is fourteen days.

SO: a luteal phase defect is a luteal phase that is not long enough.