Getting Pregnant and Fertility Drugs: Aromatase Inhibitors

Some couples may experience difficulties getting pregnant even if they experience normal ovulation and semen counts. These couples often fall into the category that is referred to as unexplained infertility.

However, there are treatment options available to these couples, just as there are for couples experiencing other types of fertility problems. Some of these options include infertility treatments such as assisted reproduction techniques or fertility drugs like aromatase inhibitors.

Aromatase inhibitors are the new, talked about drug in the line of fertility treatments. Originally used in the treatment of breast cancer and prostate cancer, aromatase inhibitors may also provide solutions to common fertility problems in the form of letrozole (Femara) and anastrozole (Arimidex).

How do Aromatase Inhibitors Work?

Femara and Arimidex work by blocking the enzyme aromatase from converting the androgens or “male” hormones into estrogen in both men and women. High levels of estrogen in both genders are linked to illnesses.

In women, high levels of estrogen and a low level of progesterone are associated with the following health concerns:

In men, high levels of estrogen are associated with prostate cancer, low sperm count, and abnormal testosterone levels. A 2006 study published in the Annals of Neurology also found that older men with high levels of estrogen levels had a greater risk of dementia.

Aromatase Inhibitors: Female Fertility

Aromatase inhibitors like Femara trigger ovulation in women. By lowering the production of estrogen, aromatase inhibitors allow for the production of the luteinising hormone (LH) and follicle-stimulating hormone (FSH), which play important roles in ovulation.

Recent studies have showed aromatase inhibiters to be a safer alternative to the two primary drugs used for ovarian stimulation:clomiphene citrate (Clomid) and FSH.

A June 2006 study published in the Contemporary OB/GYN found that aromatase inhibitors stimulated the ovaries in women who experienced the following conditions:

  • anovulation
  • ovulatory problems
  • unexplained infertility

The study also found that aromatase inhibitors produced higher clinical pregnancy rates and more frequent ovulation than Clomid —the number one form of treatment used to help women ovulate.

Aromatase inhibitors, unlike Clomid, did not affect estrogen receptors, and showed no negative effects on the endometrium (the inner lining of the uterus) or cervical mucus in women.

Women using aromatase inhibitor, like Femara, showed predictable multiple follicular responses in most cycles. This reduced the risk of multiple births associated with aromatose inhibitors, which is less than 5 %. This figure is considerably low compared to other fertility drugs that pose a risk of up to 20% for multiple births.

Pregnancy rates with the use of aromatase inhibitors are similar to those achieved by FSH injection, but cost infertile couples a fraction of what they pay for FSH treatments.

Side Effects of Aromatase Inhibitors

Women can take aromatase inhibitors orally and often experience few side effects.

Some of the common side effects of aromatase inhibitors include:

  • tender breasts
  • hot flashes
  • headaches
  • nausea or vomiting


Unlike other fertility drugs, aromatase inhibitors have not been linked to miscarriages. However, women should stop taking aromatase inhibitors upon becoming pregnant in order to prevent possible pregnancy complications and birth defects.

Since the use of aromatase inhibitors for ovarian stimulation is relatively new, it is important to speak with your health care provider or doctor for more information on the side effects and risks associated with aromatase inhibitors.

Aromatase Inhibitors: Male Fertility

Aromatase activity increases as men age. Older men often produce higher levels of estrogen, which lowers their level of testosterone as well as their sperm count. Aromatase inhibitors can slow down the conversion of estrogen by binding to the aromatase enzyme and help balance the testosterone-to-estrogen ratio in men.

Aromatase inhibitors like Arimidex, can help men improve their fertility by:

  • maintaining a healthy sperm count
  • balancing testosterone levels
  • producing healthy prostate tissues

Speak to your doctor or health care provider if you would like more information on how aromatase inhibitors can improve your fertility. Remember to ask about the potential risks and side effects of this type of fertility treatment.


Login to comment

Post a comment