How to Thicken Your Uterine Lining for Implantation

Your endometrium is the mucous membrane that covers the inside of the uterus. Since it’s the site where embryo implantation occurs, a lack of lining thickness can suddenly be top of mind during fertility treatment.

Before you run off to get every supplement you can find, you’ll need to understand why your endometrium is thin, and whether it’s a cause for concern in the first place.  

How Thick Should Your Uterine Lining Be?

Your uterine lining varies in thickness during the menstrual cycle; it may measure only 2 to 4 mm during your period, grow to around 5 to 7 mm earlier in the follicular phase, reach roughly 7 to 11 mm before ovulation, and measure around 7 to 16 mm during the luteal phase.

Estrogen drives much of that early growth, while progesterone helps mature the lining for implantation after ovulation.

During IVF or a frozen embryo transfer cycle, though, doctors need a practical way to decide whether the lining has developed enough before transfer. A lining below about 7 mm is commonly described as thin, but that figure is a practical target instead of a hard line between “pregnancy possible” and “pregnancy impossible.” Pregnancies can and do happen with thinner linings.

Doctors will also look at how the lining appears on ultrasound. Before ovulation or before progesterone starts in a medicated transfer cycle, a well-developed lining often has a trilaminar, or “triple-line,” appearance: three visible layers that give the endometrium a striped look.

Why Is Your Uterine Lining Thin?

Before jumping into solutions, it’s worth figuring out what’s causing the problem.

A thin lining can be the result of:

• Low estrogen, thyroid problems, or other hormonal issues
• Reduced blood flow to the uterus
• Scar tissue, including Asherman syndrome after uterine procedures
• Fibroids or other structural problems
• Chronic endometritis
• Clomiphene (Clomid), which can interfere with estrogen’s effect on the endometrium in some patients
• Being significantly underweight or overtraining

Sometimes, pinpointing the exact cause takes time and trial-and-error.

How to Support Your Uterine Lining Naturally

You won’t thicken your lining with one cure-all food or supplement, but you’ll improve your chances if you follow these tips:

• Give your lining the right raw materials: Your body needs the foundation to build tissue and make healthy blood. Iron-rich foods like red meat, lentils, beans, spinach, and pumpkin seeds are great, and you can pair them with vitamin C-rich foods like citrus fruits, berries, and bell peppers to help your body absorb more iron. For omega-3s and healthy fats, think oily fish, flaxseed, walnuts, avocado, and other nuts and seeds. Beets have nitrates that can help the body produce nitric oxide to support healthy blood flow.
• Keep the blood moving: You don’t need to be able to complete an Iron Man, but you need good circulation. If you don’t exercise, start off easy with 30-minute walks, yoga, swimming, bodyweight calisthenics, or cycling, and build towards a regular practice. Stay hydrated, and avoid nicotine — it constricts blood vessels. Some patients also add acupuncture to their fertility plan for circulation, relaxation, or both.
• Give your hormones a fighting chance: Estrogen helps build the lining, so this is one place where the “boring” basics do double duty. Eat enough food, get enough sleep, and don’t train too hard. You don’t need to zap all stress from your life, either; just make room for letting your hair down regularly.
• Have a good supplement stack: Vitamin E, L-arginine, CoQ10, omega-3s, iron, and vitamin D are some of the better-studied examples for supporting uterine lining health and thickness. Remember to have a one-on-one with your fertility specialist before building a supplement stack from recommendations you found online. You may already have enough of these from your diet and lifestyle, and more is not always “better.”

One last thing: Lifestyle changes can help, but not if the root cause is scar tissue, an infection, or an underlying hormonal issue.

What If Natural Methods Aren’t Enough?

If your lining chronically stays below 7 mm around ovulation or right before your clinic plans to start progesterone or perform an embryo transfer, your doctor may need to address the root cause directly.

If hormones are the culprit, your physician may adjust estrogen, which could take one to two weeks to show results. Scar tissue is different; hysteroscopy can diagnose and treat it. Thyroid problems or other hormonal conditions may also need specific treatment.

If your lining still stays stubbornly thin, some forward-thinking fertility specialists are choosing to use PRP (platelet-rich plasma) injections, G-CSF treatments, or vaginal sildenafil (for better blood flow) as experimental solutions.

When Should You See a Fertility Specialist?

If you’ve experienced recurring difficulties with uterine lining thickness complicating IVF, it’s time to find out why.

Dr. Peyman Saadat is a double board-certified reproductive endocrinologist with more than 30 years of experience treating infertility. He can look for the hormonal, structural, or treatment-related issues that may be keeping your endometrium from developing normally and adjust your fertility plan around his findings.

Schedule a consultation with us at our West Hollywood fertility center. We’ll take the time to figure out what’s been happening and map out the next steps with you.