Aspirin increases risk of miscarriages

Houston, Aug 27: Pregnant women or those planning pregnancy should avoid taking non-steroidal anti-inflammatory drugs known as NSAIDs or aspirin as they increase their risk of miscarriages, according to the findings of a new research.
Prenatal use of NSIADs or aspirin increases the risk of miscarriages by 80 per cent, especially if taken at the time of conception, when the effect is five times higher than later in pregnancy.

However, no such risk was found for those who used acetaminophen, the active ingredient in Tylenol and the like, say researchers from the Kaiser Foundation Research Institute in California.

NSAIDs, widely used to treat arthritis, work by reducing production of molecules called prostaglandins in many organs of the body, including uterus.
Aspirin has the same action. Acetaminophen also inhibits prostaglandin production, but only in the central nervous system, explained the author, whose study has been published in the British Medical Journal.

Animal studies indicate that prostaglandins are needed for implantation in the wall of the uterus, say the researchers, led by Dr De-Kun Li, a Kaiser Foundation research scientist.

Suppressing prostaglandin production "can interrupt the natural process of implantation," Li said.

Researchers in California interviewed 1,063 pregnant women in San Francisco area who were in the Kaiser Permanent health programme, immediately after their pregnancy was confirmed.

They asked them about their drug usage since they became pregnant, their reproductive history, known or potential risk factors for miscarriage, and sociodemographic characteristics.

There were 149 miscarriages among the 980 women who did not use NSAIDs, a rate of about 15 per cent. But 13 of the 53 women who used the drugs miscarried, a rate of 24.5 per cent, which meant that the risk of miscarriage for users was 80 per cent higher, the researchers said.

The numbers were similar for those who took aspirin, with a miscarriage rate 60 per cent higher for users than for non-users.

There was a slight, statistically insignificant, increase in the miscarriage rate for women who took acetaminophen. The risk was highest when NSAIDs were taken around the time of conception or when they were taken for more than a week, the report said.

Li in a webcast said that he hesitated to give advice to women on the basis of the study, because much more work was needed to prove a cause-and effect relationship.

But it is sound medical practice for women with chronic conditions that require the use of NSAIDs to consult their doctors about what to do before and during pregnancy, and that other women would do well to use acetaminophen for headaches and other minor pains.
Bureau Report