Study Links Drugs to Infertility

Certain prescription and over-the-counter pharmaceuticals may be linked to infertility in women, according to a study conducted by researchers at the School of Public Health (SPH).

An article appearing in today's issue of the journal Epidemiology reports on the study, which establishes a correlation between the use of certain pharmaceuticals and infertility.

Assistant Professor of Epidemiology Marlene B. Goldman, one of the paper's authors, emphasized in a phone interview last week, however, that the study, the first of its kind, was preliminary and does not signify a causal relationship between the drugs and infertility disorders.

The article cautions that the results could mean that infertility was an effect of the disorders suffered by the women rather than the medications which were used to treat them.

The paper's authors write that while "over 1.5 billion prescriptions were filled by pharmacies in the United States 1990...little is known about the effect that many of these drugs have on reproductive capacity in women."

The researchers studied women who reported the use of nine types of medication: antibiotics, thyroid supplements, antihistamines, pain relievers, tranquilizers, antidepressants, and asthma, seizure and hypertension medications.

Over the course of interviewing women who had used one of the studied drugs for at least six months, researchers concluded that the women who had used thyroid replacement hormone had doubled their relative risk of ovulatory dysfunction.

Hormone users were at the same risk regardless of the age they began taking the drug, or the length of time they had used the hormone.

Women who had used antidepressants for more than six months had tripled the relative risk of infertility. Those who were currently using tranquilizers and those who had previously used them for more than two years had also tripled their risk.

Additionally, subjects who had used asthma medication prior to the age of 21 approximately doubled their risk of ovulatory dysfunction. For users of asthma medication, the risk level was higher the earlier they had begun taking the medication.

According to Dr. Jon Graff, an endocrinology resident at Massachusetts General Hospital, women suffering from hypo-thyroidism are "very commonly infertile" as a result of their condition.

Graff said that those who received proper dosages of thyroid hormone often show increased fertility. He said infertility commonly results from overdosage or underdosage of thyroid hormone.

Since the results were only preliminary, Goldman said there was no cause for scare. Women "should certainly continue" to use any medication which they currently need, she said.

Goldman advised any woman planning a pregnancy to consult her physician to determine safe medications

The researchers studied women who reported the use of nine types of medication: antibiotics, thyroid supplements, antihistamines, pain relievers, tranquilizers, antidepressants, and asthma, seizure and hypertension medications.

Over the course of interviewing women who had used one of the studied drugs for at least six months, researchers concluded that the women who had used thyroid replacement hormone had doubled their relative risk of ovulatory dysfunction.

Hormone users were at the same risk regardless of the age they began taking the drug, or the length of time they had used the hormone.

Women who had used antidepressants for more than six months had tripled the relative risk of infertility. Those who were currently using tranquilizers and those who had previously used them for more than two years had also tripled their risk.

Additionally, subjects who had used asthma medication prior to the age of 21 approximately doubled their risk of ovulatory dysfunction. For users of asthma medication, the risk level was higher the earlier they had begun taking the medication.

According to Dr. Jon Graff, an endocrinology resident at Massachusetts General Hospital, women suffering from hypo-thyroidism are "very commonly infertile" as a result of their condition.

Graff said that those who received proper dosages of thyroid hormone often show increased fertility. He said infertility commonly results from overdosage or underdosage of thyroid hormone.

Since the results were only preliminary, Goldman said there was no cause for scare. Women "should certainly continue" to use any medication which they currently need, she said.

Goldman advised any woman planning a pregnancy to consult her physician to determine safe medications