Fever is a defense mechanism!!

Study Suggests Fever Doesn’t Up Miscarriage Risk

NEW YORK (Reuters Health) – Pregnant women who have a fever during the first 16 weeks of pregnancy are not at an increased risk for miscarriage, a new study from Denmark suggests.

While the findings offer some reassurance to pregnant women concerned about the risks posed by fever, the researchers note that they were unable to assess the risk of fetal death before the sixth week of pregnancy.

“We have no data on very early pregnancy losses and cannot rule out that fever is associated with fetal loss in the preclinical phase of pregnancy,” write lead author Dr. Anne-Marie Nybo Andersen of the University of Copenhagen and colleagues.

Previous research in animals has led some scientists to suspect that pregnant women who develop a fever may be at increased risk of having a miscarriage. However, few studies in human beings have investigated the association between fever and miscarriage, according to the report published in the November 16th issue of The Lancet.

In the current study, Andersen and colleagues interviewed 24,040 pregnant women who were still in the first half of their pregnancy. The investigators obtained information about the number, if any, of fevers each woman had, how high their temperatures were and how long the fever lasted, among other information. They focused on the first 16 weeks of pregnancy, when a fever would be most likely to harm the fetus.

In all 1,145 women had a miscarriage. During the first 16 weeks of pregnancy 18.5% of the women reported that they had a fever, which signifies that fever during pregnancy is quite common.

“However, we found no association between fever in pregnancy and fetal death before or after adjustment for known risk factors of fetal death,” the authors write.

“Therefore, pregnant women need not fear a fetal death after an episode of fever,” Andersen and colleagues conclude.

Commenting on the study, Drs. Christina D. Chambers and Kenneth Lyons Jones of the University of California in San Diego write that “because of the substantial barriers associated with the study of (miscarriage) or fetal death, it is hard to imagine a feasible prospective study design that would be superior to that by Andersen and colleagues in addressing the risk associated with maternal fever.

“However, it is difficult to categorically conclude from this study, as do the investigators, that pregnant women need not fear a fetal death following an episode of fever,” Chambers and Jones conclude.

SOURCE: The Lancet 2002;360:1526, 1552-1556.