By Eulalee Thompson, Staff Reporter 
SOME OF the common over-the-counter painkillers have been linked by California researchers to miscarriages. The risky painkillers were identified as the non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and aspirins.
However, the study (De-Kun Li, Liyan Liu, Roxana Odouli),
published in the August 16 edition of the British Medical Journal, indicated that taking another painkiller, paracetamol, during pregnancy, is safe.
Medical practitioners have always been cautious in prescribing painkillers to pregnant women. This caution had been supported by researchers in Denmark, who published a 2001 study indicating a possible link between NSAIDs and miscarriage, however, the latest study also suggests that miscarriage risk applied even to women who took the painkillers around the time of conception.
The study, based on a relatively small sample size of 1,055 pregnant women, also point to a five times more likely risk of a miscarriage in women who took NSAIDs at the beginning of their pregnancies compared to women who took them later in their pregnancies.
Generally, according to the study, there was an 80 per cent increase in the chance of a miscarriage in women who took these NSAIDs at any point in their pregnancy. The researchers also found that the risk increased when the drugs were used for longer than one week but these risks were not affected by other factors such as drinking alcohol or coffee.
ASPIRIN USE
The researchers say that the miscarriage risk with the prenatal use of aspirin was similar to that of prenatal NSAIDs use, but they indicated that "the association was generally weaker and the estimates unstable because of the small number of aspirin users" (in the study).
PARACETAMOL USE
The researchers report that "use of paracetamol during pregnancy was not associated with risk of miscarriage regardless of the timing or duration of use".
The researchers report that their data revealed a significantly increased risk of miscarriage associated with prenatal use of NSAIDs or aspirin that the risk was particularly high when the drugs were used around the time to conception.
WHY MISCARRIAGE?
The researchers say that a possible explanation for the miscarriage risk when NSAIDs are used prenatally and in pregnancy could be found in the effect the drugs have on the body's hormone-like substances known as prostaglandins. It is believed that these substances are important in ovulation and are needed for the successful implantation of embryos to the walls of the uterus. However, NSAIDs, are said to inhibit the action of prostaglandins in most organ systems.
NSAIDs when taken for pain, act by inhibiting the enzymes responsible for the formation of prostaglandins - important actors in inflammation. The researchers say that "paracetamol inhibits prostaglandin biosynthesis only in the central nervous system".
