The Luteal Phase Explained And Why It Matters To Fertility

Learning about the luteal phase in your cycle is a powerful step, whether you are trying to conceive or simply want to understand your body. The luteal phase refers to the period after ovulation until menses, when your body prepares for potential implantation and pregnancy. So, a healthy luteal phase is key to achieving a successful pregnancy. In fact, luteal phase defects are one of the common reasons for infertility and miscarriage. In this blog, we will talk about what the luteal phase is, how it matters for fertility, and how you can maintain a healthy cycle.

Let’s start by understanding what exactly happens during this time.

What Is the Luteal Phase?

The luteal phase starts on the first day after ovulation and ends on the day before menses. Assuming your cycle is 28 days, and ovulation happens on day 14, the luteal phase refers to day 15-28, the second half of your cycle. At ovulation, a mature egg is released from the follicle sac. After ovulation, empty follicles turn into corpus luteum. Corpus luteum produces progesterone, which helps the uterine lining thicken and stay in place to prepare for potential implantation. The uterine lining acts like a soft bed for a fertilized egg to rest and grow. If implantation or pregnancy does not occur, corpus luteum degenerates, and progesterone level drops. As a result, uterine lining sheds, resulting in menses.

As progesterone rises during this phase, your body mimics an early pregnancy state. That is why many women experience symptoms before their period, including bloating, fatigue, food cravings, tiredness, mood changes, etc. These symptoms are referred to as PMS (Premenstrual Syndrome).

Why the Luteal Phase Is Critical for Fertility

You might already have an idea why luteal phase matters for fertility. As we talked, uterine lining works as a bed for a fertilized egg, and it’s where the egg grows into a fetus. Imagine if your bed is not well built. If you lay down, your bed frame is wobbly and collapses! On the other hand, if it’s sturdy, you can lie down comfortably. As such, if your uterine lining is not sufficient, the egg is not able to implant and grow. Low levels of progesterone or estrogen can result in a thin uterine lining. Estrogen helps the lining grow, while progesterone keeps it stable within the uterus. So, both hormones play vital roles.

Luteal Phase Defect (LPD): What You Should Know

Now that we understand its importance, let’s look at what can go wrong. A Luteal Phase Defect (LPD) occurs when the corpus luteum does not produce enough progesterone. In short, your body does not produce enough progesterone to keep the luteal phase. Causes include ovulation defects, hormonal imbalances, endometriosis, Polycystic ovary syndrome (PCOS), etc. Common symptoms include short cycles and infertility.

Supporting a Healthy Luteal Phase

So how can we support a healthy luteal phase? In short, you should have a healthy cycle as a whole, not only the luteal phase. Corpus luteum produces progesterone. For corpus luteum to form, ovulation needs to occur and form an empty follicle. For ovulation to occur, pre-mature eggs need to develop in the follicular phase. So, your cycle is all connected as a whole. To have a healthy luteal phase, having a healthy follicular phase is a must. It might sound simple, but lifestyle is the foundation of a healthy cycle and balanced hormones. Rather than spending money on fancy supplements and wellness goodies, stick to the basics! Here are some tips.

• Nourish your body with whole foods
• Exercise regularly (but don’t overdo it)
• Prioritize getting enough sleep
• Support emotional well-being

When to Seek Help

Many people experience various symptoms in the luteal phase. Knowing when to seek professional help can make a big difference in your reproductive journey.

– Short luteal phase (under 9 days)
– Long luteal phase (more than 18days)
– Irregular cycles
– Spotting, irregular bleeding
– Difficulty conceiving despite timed intercourse
– Extreme pain

These could be signs of Luteal Phase Defect or other hormonal issues. Even if your symptoms are not listed above, if you think something is extreme or abnormal, seeking help from a fertility expert like a Reproductive Endocrinologist is a good option.

Remember: It’s Just a Phase!

Every phase of our cycle has a purpose. The luteal phase can be a sensitive time for some people. As hormone levels fluctuate, you might notice changes in your body and emotional state, which can feel overwhelming. During this time, it is especially important to listen to your body’s signals. Honor your experience by adjusting your routine to meet your needs- whether that means practicing mindfulness, adding or modifying exercise routines, or getting support from loved ones.

By prioritizing your well-being, you’re not only improving your chances of conception but also supporting your overall health. Self-care is a vital part of the process, and you do not have to figure it out alone – reaching out for help is a sign of self-awareness as well.

Written by Shiho Yoshida

Shiho is a Biological Analyst at Seattle Sperm Bank, where she is responsible for the cryopreservation process and preparing vials. She holds a Bachelor of Science in Molecular, Cellular, and Developmental Biology from the University of Washington. She is also certified as a women’s health and fertility educator through FEMM Health.