Fever in pregnancy associated with adverse health outcomes for children

By Will Boggs MD

NEW YORK (Reuters Health) - Fever during pregnancy is associated with a higher risk of certain birth defects, according to a new meta-analysis.

"The available evidence does suggest that fever in pregnancy is associated with some adverse health outcomes in the child," lead author Julie Werenberg Dreier from University of Southern Denmark in Esbjerg told Reuters Health in an email. "However, since the evidence is primarily dealing with rare diseases (e.g., neural tube defects, oral clefts, heart defects), then the overall risk of having a child suffering from any of these conditions is still very small, even if the mother does get fever while being pregnant."

Although about one in five women reports having at least one febrile episode during pregnancy, there have been no systematic analyses of the impact of maternal fever on overall health outcomes in human offspring.

To address that gap, Dreier, a doctoral candidate, and colleagues reviewed 46 studies on the subject, each including about 100 to 100,000 observations.

Studies included in the meta-analyses were restricted to preconception and first-trimester fever exposure, they note.

Fever in pregnancy was associated with a 2.9-fold increase in the risk of neural tube defects, a 94% increase in the risk of oral clefts, and a 54% increase in the risk of congenital heart defects, according to the February 24 Pediatrics online report.

Most studies found no association between maternal fever and such pregnancy outcomes as spontaneous abortion, stillbirth, preterm birth, and birth weight.

Studies conducted prospectively were more likely to report lower risk estimates (or no effect of fever) than were studies with retrospective assessment of fever.

Most, but not all, studies suggested a protective effect of antipyretic medications.

"Based on what is currently known, it is difficult to make any solid recommendations regarding management of fever in pregnant women," Dreier said. "Our review does show that there is evidence supporting an association with several adverse health outcomes in the child. However, we still need more research considering whether fever might only be harmful under certain circumstances (e.g. at a very high temperature or long duration), whether fever is harmful throughout pregnancy or only in the first part, and last but not least, which diseases the child has an increased risk of developing if the mother had a fever while she was carrying the child."

"This article is an important step in the efforts to define whether fever should be considered as a public health concern or not," Dreier said. "The review outlines what is currently known, but equally importantly what we don't know a lot about yet. We therefore hope that future research will address these knowledge gaps, so solid recommendation regarding management of fever in pregnant women can be made."

SOURCE: http://bit.ly/1ptTazE

Pediatrics 2014;133:e674-e688.

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