All About Luteal Phase Defect

All About Luteal Phase Defect

Have you heard of a luteal phase defect? Luteal phase defect -- or a short luteal phase -- is what caused Proov founder Amy Beckley to experience years of infertility and multiple miscarriages. Simply put, Amy’s luteal phase defect meant she wasn’t ovulating properly. And it prevented her from having a successful pregnancy for years.  

What is the luteal phase?

Before we can talk about luteal phase defect, we need to understand what happens in the luteal phase, which occurs in the second half of a woman’s cycle. The luteal phase starts after ovulation occurs and ends the day your period starts. 

It is named for the corpus luteum, which is the empty follicle from which the egg is released. During the luteal phase, the corpus luteum secretes progesterone, which is the hormone that stabilizes the uterine lining (endometrium) and prepares it to be receptive to an embryo and allow for implantation. Also during this time, the progesterone stimulates blood vessels to grow, which is how a growing embryo receives nutrients and oxygen.


What is a luteal phase defect?

A luteal phase defect is an abnormality in endometrial development, which means the endometrium doesn’t develop as it should each month1. It can be caused by a below normal secretion of progesterone from the corpus luteum, or by the endometrium failing to respond to hormone stimulation2. Due to either of these causes, the luteal phase is shorter than normal. A luteal phase is considered short when it lasts less than 10 days3, while a normal luteal phase usually lasts anywhere from 11-17 days. 

In Amy’s case, her corpus luteum wasn’t secreting enough progesterone after ovulation. While she was ovulating, she didn’t have a “healthy” or “normal” ovulation that allowed her to conceive successfully. It wasn’t until she discovered this issue that she was able to seek inexpensive, non-invasive treatment to fix the problem -- a treatment that resulted in her beautiful (now 6-year-old) daughter!

It’s important to note many experts question the existence of luteal phase defect because of the difficulty of diagnosis.1 Some experts who recognize luteal phase defect believe it can be associated with infertility and miscarriage, while others don’t. An association with infertility and miscarriage would make sense, because if the endometrium isn’t prepared to receive an embryo, pregnancy isn’t possible.


How can I tell if I have a luteal phase defect?

The most common symptoms of luteal phase defect include infrequent periods, spotting between periods, trouble getting pregnant, and miscarriage4. While there is no single test to diagnose luteal phase defect, an endometrial biopsy is one of the most widely accepted procedures in determining this diagnosis.


How can Proov help me when it comes to trying to conceive?

Because luteal phase defect is often associated with ovulatory problems, it can be helpful to determine if you are successfully ovulating. Proov is the first and only 5-minute, at-home test to confirm ovulation. It works by measuring PdG -- the urine metabolite of progesterone -- after ovulation. Tracking with Proov can help confirm if successful ovulation has occurred, or if there may be lack of ovulation or suboptimal ovulation that could be making it difficult to conceive. 

While negative Proov results don’t necessarily mean you have a luteal phase defect, it could mean that problems with ovulation are getting in the way of successfully conceiving. You should always reach out to your doctor for a proper diagnosis.  

Have any questions? We’re always here to help! Don’t hesitate to reach out


1“Luteal Phase Defect - RESOLVE: The National Infertility Association.” RESOLVE, 2020,

2Engman, Lawrence. “Luteal Phase Deficiency: What We Now Know.” MDEdge ObGyn, OBG

Management, 28 Aug. 2018,

3Higuera, Valencia, and Debra Rose Wilson. “Short Luteal Phase: Causes, Symptoms, and

Treatment.” Healthline, Red Ventures Company, May 19AD, 2017,

4Johnson, Traci C. “Luteal Phase Defect (LPD): Symptoms, Causes, and Treatment.” WebMD,

WebMD, 14 Feb. 2019,