Thickness of the endometrium: norm and abnormalities

The chances of conceiving and carrying a pregnancy to term depend on many factors. If you are considering having a child, it is recommended to undergo a complete assessment of your reproductive health beforehand. For a woman wishing to have a child, the thickness of the endometrium (the mucous membrane that lines the uterus) is one of the key indicators. An excessive thickening or insufficiency of the endometrium can indicate abnormalities that should not be ignored.

What is the endometrium and what is its function?

The endometrium is the mucous membrane that lines the inner wall of the uterus. It is where the fertilized egg attaches. Its thickness has a direct influence on the embryo's implantation process: if it is not normal, the chances of pregnancy are considerably reduced. Abnormalities in the structure or thickness of the endometrium can be one of the causes of infertility. Modern medicine offers effective methods to treat reproductive disorders, and the Natuvitro medical center has all the necessary resources.

Normal thickness of the endometrium during different phases of the cycle

The thickness of the endometrium normally varies throughout the menstrual cycle. During menstruation, the functional layer is shed and eliminated from the body, then it rebuilds. In women of childbearing age, a thickness between 5 and 14 mm is considered favorable for implantation, depending on the phase of the cycle:

• Menstruation: 2 to 4 mm;
• Follicular phase: 5 to 7 mm;
• Ovulation: 10 to 12 mm;
• Luteal phase: 12 to 15 mm.

After fertilization, hormone levels increase and the endometrium can thicken up to 20 mm. After menopause, a maximum thickness of 5 mm is considered normal.

Endometrium and conception: when are the chances highest?

For successful conception, the thickness of the endometrium should be around 10 mm, but a range of 8 to 14 mm is acceptable. In addition to thickness, the structure of the endometrium is also important. During an ultrasound, specialists evaluate:

• The basal layer: about 2 mm, stable;
• The functional layer: which varies throughout the cycle under the influence of hormones.

The visualization of the three-layer structure and the absence of pathologies are important conditions for conception.

Preparation of the endometrium for in vitro fertilization

IVF: Standard protocol

The embryo is transferred to the uterus on the 3rd to 5th day of its development, which corresponds to the post-ovulatory phase. When the thickness of the endometrium is less than 7 mm, the chances of successful implantation decrease.

IVF with egg donation

Receiving women are prescribed hormonal treatment: estrogens to thicken the mucosa and progesterone to prepare it. The ideal thickness is 8 to 14 mm.

IVF with double donation

Eggs and sperm from donors are used. A particularly careful preparation of the endometrium is necessary: three-layer structure, sufficient thickness, and good visualization on ultrasound.

IVF in cases of endometrial hyperplasia

Before starting the protocol, treatment is performed:

• Progestins, anti-estrogens, hormonal IUDs;
• Control ultrasound and biopsy;
• IVF is only possible after normalization of the structure and thickness.

Hyperplasia is not an absolute contraindication but requires strict monitoring.

Age standards for endometrial thickness

The standards vary depending on age and the state of the body:

• Before menarche: 0.3 to 0.5 mm;
• Reproductive age: from 7-9 mm to 12-15 mm;
• Postmenopause: 5-8 mm.

A thickness greater than 12 mm at menopause requires the exclusion of hyperplasia or cancer. It is recommended to regularly perform ultrasound, not just during a pregnancy project.

Up to what age can a woman conceive?

After 35, fertility decreases and after 40, ovulations become irregular. However, IVF allows a woman to conceive even after 45.

With age, the uterine mucosa reacts less well to stimulation; hypoplasia or hyperplasia is possible. Preparation includes:

• ultrasound, biopsy, hysteroscopy;
• hormonal treatment;
• if necessary, egg donation or double donation.

Age is not an obstacle to motherhood, but it requires an individual approach and special medical monitoring.