Dear Dr. Poyner,

I have been using Vagifem, a vaginal estrogen, twice a week because I had pain with intercourse without it. This has worked really well along with a lubricant that I use when I have intercourse.

I am 70 and have a pelvic sonogram once a year to make sure that the vaginal estrogen does not cause any thickening in the lining of the uterus. My gynecologist said that it would be unusual for this to happen, but that there are some risks to all estrogen products, even this one. She said that if the lining of the uterus remained thin and if I had no post menopausal bleeding that I could be comfortable with the decision to use this local hormone therapy which has made such a difference in my life.

My last sonogram showed that the lining of the uterus (the endometrium it said on the ultrasound report) was 2 mm. But, there was the development of something new called hydrometria. The report described the hydrometria as “small”. I was certain that I would need a D&C when I heard this. However, my gynecologist said that we don’t know what causes the development of this fluid in the cavity of the uterus and that repeating a sonogram in 3 months would be enough. I know you can’t diagnosis or recommend treatment for me, but would you tell me how serious “hydrometria” is and how it is generally monitored? What causes it anyway?

Gina

Dear Gina,

Vaginal estrogen is generally considered safe but your gynecologist is doing the right thing to monitor the potential impact of local estrogen absorption and its possible impact on the lining of the uterus. The lining of the uterus is called the endometrium. Vaginal estrogen, could have an impact on the cells of the endometrium, causing the cells to become hyperplastic (in some cases this is pre-malignant) or even malignant. Your gynecologist is using ultrasound imaging of the uterus and the endometrium to monitor the endometrium to detect thickening of the endometrial lining.

Medical terms are often annoying since the inhibit easy discussion of the real issues. Hydrometria is just a collection of fluid in the uterine cavity, a not uncommon ultrasound finding in postmenopausal women. It is generally not serious, if all else is normal on the ultrasound. The cause is often related to an obstruction in the endocervical canal or the cervical opening that often results from prolonged loss of estrogen or other age related change.

Doctors have to understand and evaluate information like fluid in the endometrial cavity so that nothing unnecessary is done, but more importantly to patient and doctor, nothing serious is overlooked.

We make our decisions based on a careful reading of the medical literature and from our clinical knowledge and experience.

In one study of 1,000 postmenopausal women without any abnormal symptoms (such as abnormal bleeding, pelvic pain or abnormal discharge) uterine fluid was found in 134, or 12% of these women. An endometrial biopsy in the office was attempted in all 134 patients, and in 12 a biopsy could not be performed due to cervical scarring. Of the greater than 100 patients who had a successful endometrial biopsy, only one was found to have a cancer, and the rest had no abnormal cellular change on pathological exam. One patient who refused a biopsy was diagnosed with cancer approximately 2 years later. Women who used estrogens were 3 and 1/2 times more likely to have uterine fluid. Of note, uterine fluid has also been demonstrated to be found more frequently in women who are taking the breast cancer prevention and treatment drug tamoxifen. This drug has estrogen like activities on the endometrial lining.

Ultrasound findings which would require additional intervention, either an endometrial biopsy or D&C, are thickened endometrium, or fluid that is not completely clear. If the endometrium is thickened, the chances of cancer or precancers is increased. We know however that we can not rely solely on the measurement of the endometrial thickness in order to determine if a cancer is present. Case reports do exist of cancers found when the endometrium is of normal thickness on ultrasound. Careful followup of endometrial change then is always important.

Post menopausal bleeding is one of the most important signs of endometrial cancer. Women who have a cervical stricture may have blood inside the endometrial cavity but may not have this important sign of endometrial cancer, postmenopausal vaginal bleeding. On ultrasound, the fluid in the endometrial cavity of these women may be echogenic or complex. This is always an indication for additional sampling of the endometrium, which may include an endometrial biopsy or D&C. It is always important to confirm with your physician that the cervix and other pelvic structures such as the tubes and ovaries appear normal at the time of the ultrasound, since cervical cancer, and cancer of the ovary and fallopian tubes may be associated with hydrometria.

This is what we know.

• Asymptomatic uterine fluid is not an uncommon finding in post menopausal women;
• If the hydrometria, or endometrial fluid, is not associated with abnormal bleeding, unusual discharge, thickened endometrium or abnormalities of the cervix, tubes and ovaries, sampling of the endometrium may not be indicated;
• Women who use estrogens and tamoxifen have a higher likelihood of uterine fluid and must have more intense follow up.Endometrial fluid which could represent blood in the endometrial cavity always requires additional evaluation.
• If follow up ultrasounds find an increase in the amount of endometrial fluidor other endometrial abnormalities, further evaluation would be necessary.

The problem with hydrometria is often that doctors will only know if it is a serious problem by following the patient closely over time. Doctors and patients are united in their need to know what a new finding on a diagnostic test means, but sometimes observation is the best treatment.

Dr. Elizabeth Poyner