The endometrium is the bed of the uterine cavity. It is soft and like a cushion. It is the essential part of the uterus because it is here that the embryo implants, is nurtured and grows to be born after 9 months ultimately.
The endometrium develops over 3 weeks of the month until a week after ovulation. If it receives the signals for implantation, it grows further to nurture and allows the developing embryo to grow. It further thickens and gets filled with blood vessels and blood lakes. If implantation does not occur, the endometrium thins down and sheds, resulting in menses.
The uterine lining is a lay term to define the endometrium.
In this blog, we’re going to talk about the ideal thickness of the thin endometrial lining, why it happens, symptoms it causes, and how to diagnose it.
Benefits of thick endometrium
Multiple studies have suggested that thick endometrium brings benefits like positive β-hCG, live birth rates, successful embryo transplant and more. It also helps the embryo to get the nutrients it needs.
The ideal thickness of the lining is between 8 mm to 12 mm. If the lining is thinner than 8 mm, it suggests that there is some pathology in the lining or an inadequate blood supply to the uterine lining. If the endometrium thickens beyond 12 mm. The chances of implantation come down, and the lining can then develop polyps which may prevent implantation.
Traditional teaching and scientific articles suggest that the lining should be 8 mm thick or more to promote implantation. A suitable thickness is essential to promote implantation and prevent miscarriage and ectopic pregnancy.
What happens if the endometrium is thin?
A thin endometrium lining does not promote implantation. It can also cause miscarriages or biochemical pregnancies, in which case the pregnancy will not continue. A thin lining may also cause an ectopic pregnancy. Since the lining is thin, the embryo will seek a more cushiony place to implant. This could be the fallopian tubes.
Which hormones play an essential role in keeping the endometrium thick?
Both estrogen and progesterone are required in the right amounts to ensure the thickness and healthiness of the uterine lining.
5 Major Reasons For Thin Endometrium Lining
Women may need to undergo multiple rounds of IVF if they have thin endometrial linings. Some reasons for a thin endometrial lining include the following:
#1. Low estrogen levels
Low oestrogen levels are observed when a woman does not ovulate or has deficient estrogen secretion due to poor ovarian reserve or being menopausal or perimenopausal.
- Why is this important?
Adequate oestrogen levels are essential to maintain the hormonal environment of the uterus, to maintain the development of a healthy egg and for proper implantation. Adequate oestrogen levels promote adequate progesterone levels in turn.
- What is the normal range of estrogen?
The normal range of estrogen levels in premenopausal women is 30 to 400 pg/mL where it should be 0 to 30 pg/mL in postmenopausal women. In men, it will be somewhere between 10 to 50 pg/mL.
The oestrogen levels start rising after the menses and continue to rise till ovulation. After ovulation, there is a slight fall. If implantation does not occur, the oestrogen levels continue to fall till such levels do not support the proliferation of the endometrium. The endometrium thins down, and the periods start. If implantation occurs, signals are sent to the ovary, which secretes more oestrogen and progesterone to support the early pregnancy.
- How to replenish your low estrogen levels?
Low estrogen levels can be supplemented with the help of oestrogen tablets, patches and estrogen creams. They can also be increased with injections of b hCG.
#2. Damaged estrogen lining
The endometrial lining can get damaged due to acute or chronic infection. Acute infections are usually bacterial. Chronic infections can be caused by an acute infection that is not eliminated and hence becomes chronic. The most typical cause of a chronic infection in our country is female genital Tuberculosis. A chronic infection results in an increase in inflammatory cells in the endometrium. These are plasma cells and are called CD138 cells.
If the acute or chronic infection is picked up early enough, it can be fixed with the help of oestrogen, antibiotics or anti-TB medication.
#3. Decreased blood flow
The uterus is a vascular organ getting its main blood supply from 2 big arteries called the uterine arteries. These branch into smaller blood vessels that run through the uterus and into the endometrial lining. If the blood supply does not reach the way to the endometrial cavity, it can affect the functioning of the lining and prevent implantation. It can also cause a decreased duration of blood flow and a scanty blood flow.
What tests can spot this issue?
Colour blood flow of the uterine vessels can spot this issue. Since this also results in a thin lining, an ultrasound scan can detect a thing and an irregular lining.
If caught early, it can be fixed by giving medication like viagra and pentoxifylline both dilate the blood vessels, thus allowing more blood to flow through the blood vessels. If a chronic condition sets in, it can become irreversible.
#4. D & C or any Surgeries
A thin lining can be caused by a very sharp or traumatic D & C or other surgeries like hysteroscopic metroplasty, hysteroscopic adhesiolysis, or polypectomy. Sometimes Surgeries like Caesarean section can also harm the uterine cavity. Removal of deep-seated fibroids can damage the uterine lining hence the procedure should be done by experienced surgeons and laparoscopists.
#5. Birth Control Pills and Clomiphene citrate
Mini Pills can thin down the lining temporarily.
Doctors usually recommend Clomid (clomiphene citrate) as a medication for fertility, but it has one possible side effect that can thin down the line temporarily.
Symptoms of thin endometrium
Here are some of the common symptoms related to the thin endometrial lining.
- Infertility: A thin lining can cause infertility by preventing proper implantation. It can also lead to biochemical pregnancies and ectopic pregnancies. These issues can lead to infertility.
- Abnormal or irregular menstrual cycle. Chronic endometritis and a thin lining can cause menstrual irregularities, spotting in the cycle at odd times and decreased time and quantity of blood flow.
- Irregular or painful menses. Chronic endometritis can cause vaginal discharge and congestion of the pelvic vessels and organs and thereby cause irregular and sometimes painful menses.
- Inadequate menstrual bleeding: It is a sign of thin endometrium, chronic endometritis and an acute infection that lasts long enough to become chronic.
What is the treatment for thin endometrium?
GCSF and PRP are substances that contain growth factors and thereby improve the composition and thickness of the uterine lining.
How to diagnose Thin Endometrium?
A thin lining can be diagnosed by transvaginal sonography, colour blood flow studies, a 3-D and 4-D ultrasound, Hysteroscopy and sometimes by Hysterosalpingography.
Frequently Asked Questions
Does stress affect endometrial lining?
No, stress doesn’t directly affect endometrial lining. Stress can have negative effects on male and female fertility.
How does a thin endometrium affect pregnancy?
It is possible to experience infertility due to a thin lining as it prevents proper implantation. Additionally, Ectopic pregnancies and biochemical pregnancies can also happen.
Is thin endometrium normal?
Thin endometrium is not normal, but it’s not uncommon.
Can thin uterus lining cause miscarriage?
Yes, thin endometrium can result in a poor implantation, which can lead to miscarriage.
How to thicken the endometrium?
You can thicken the endometrium with GCSF & PRP. GCSF strands for Granulosa colony-stimulating factor is a ready-made injectable preparation that increases the blood supply to the endometrium and supplies growth factors to the endometrium. Platelet-rich plasma is derived from the woman’s platelets and has many growth factors which enrich the endometrium and make it more receptive.
What is the cause of thin endometrium?
Thin Endometrium can be caused by a number of things, including:
- hormonal imbalance
- lack of estrogen (due to breastfeeding, perhaps)
- ovarian failure
Is it possible to get pregnant with thin endometrium?
Yes, it is possible to get pregnant with thin endometrium. Even a lining of 6 mm can result in a pregnancy. However it is rare as the lining has to be thick and filled with blood vessels in order to support a healthy pregnancy.
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