The uterus is the largest in size of the female reproductive organs, which is the site of implantation of a fertilized egg and where the fetus ultimately grows to maturity. The size of the uterus will fluctuate based on a variety of factors such as age and hormone levels. And sometimes, some diseases may be related with the change. 

What Is Normal Uterus Size?

Determining if a woman has a normal sized uterus is important in the evaluation of health and reproductive capacity.

Size Before Puberty

The prepubertal uterus is about 3.5 cm in length and thickness is on average 1 cm. Hormonal stimulation that occurs during puberty will result in rapid growth and changes in the size of the uterus.

Size After Puberty

The normal length is about 7.6 cm and width is 4.5 cm. The average normal thickness is 3.0 cm and in an adult female, the uterus weights about 60 grams but ranges up to 200 grams depending on various conditions.

What If Having Enlarged Uterus Size?

A variety of factors can result in enlargement of the uterus. Size fluctuates monthly with the menstrual cycle, but other conditions such as fibroids and endometriosis can influence the size as well.

Menstrual Cycle

The normal surge of hormones at different stages of the menstrual cycle affects the size of the uterus. The lining builds up internally and then later is sloughed off and results in a menstrual period.

Pregnancy

This results in the most dynamic changes in uterine size. As the pregnancy progresses beyond 12 weeks, the uterus begins to rise up out of the pelvis. At 20 weeks, the fundus, or top, of the uterus is felt at the level of the belly button. The growth continues until the baby is delivered around 39 weeks of gestation.

Fibroid 

The medical term for the benign muscular growths is leiomyoma. They can be small in size or increase up to grapefruit size or larger. Fibroids can occur in various locations and can interfere with pregnancy, cause pain or bleeding.

Endometriosis

This condition is often quite painful and results from endometrial tissue spreading beyond the normal lining of the uterus. This tissue can be found on the ovaries, intestines and outer surface of the uterus. The uterus can become firm, inflamed and hard on palpation. This condition commonly results in enlarged uterus size, chronic pelvic pain and infertility.

Pelvic Congestion Syndrome

The pelvic reproductive organs are rich in blood supply. In this condition, the veins do not drain blood adequately and the uterus becomes congested and engorged in blood. Common symptoms include chronic dull pain, pressure, and heaviness. Many believe that varicose veins develop in the pelvis and contribute to the development of this condition.

Contraceptive Use

Contraceptives work by manipulating hormone levels in the body and this influences uterine size and thickness.

Cancer

Uterine cancers or cervical cancers can influence the size of the uterus. Early detection is important and treatment varies depending on the location and stage. Annual pap smears are an important screening tool. Any women experiencing vaginal bleeding after menopause must see a doctor as this is a potential sign of endometrial cancer.

Duplex Uterus

This is a very rare condition and can exist in several variations. The overall result is a larger than normal uterus. Some women are never aware and this condition goes undiagnosed. This condition is likely higher in those who have suffered a miscarriage or given birth prematurely. Treatment is only indicated if symptoms develop or pregnancy is inhibited or miscarriages recur.

What If Having Shrunken Uterus Size?

The uterus fluctuates in size throughout life and puberty, pregnancy and menopause are the specific times of greatest change. Shrinkage of uterus occurs less compared to enlarged uterus. The causes could be the following. 

Age

The age of the patient has an impact on the overall size of the uterus. With age and as the female gets past menopause, the hormonal levels decrease and the uterus shrinks in size. As the hormone production decreases, the ovaries also shrink in size.

Prolapsed Uterus

Factors such as age, pregnancy and pelvic floor muscle weakness result in the uterus sliding down and protruding into the vagina. Symptoms depend on the severity of the prolapse. Mild cases are generally without symptoms and discovered incidentally on a physical exam. More severe cases can result in fullness or heaviness in the pelvis, tissue sticking out of vagina, bladder problems such as leaking of urine or difficulty empting the bladder fully, constipation and back pain. Some note the sensation of sitting on a ball or balloon. Sexual relations can suffer if the prolapse is significant.