Researchers Warn Pregnant Moms to be Wary of Flu Outbreak

Newswise — Pregnant mothers should be particularly wary of the nation's current flu outbreak. That's because recent research has found that women who experience fever during their second trimester of pregnancy are more likely to give birth to children who develop emotional and psychological disorders " including inhibition, negative emotionality and attention deficits.

In a first of its kind study, Dr. Stefan Dombrowski, assistant professor of graduate education (school psychology) at Rider University; Dr. Roy P. Martin of the University of Georgia; and Dr. Matti Huttunen of the University of Helsinki, report that elevated temperatures during that time period may have an adverse effect on the development of the central nervous system of the fetus, resulting in abnormalities of psychological development and behavior that can be observed in childhood.

The study, "Association Between Maternal Fever and Psychological/Behavior Outcomes: A Hypothesis," was published in the November issue of Birth Defects Research Part A: Clinical and Molecular Teratology -- a professional journal. Among its key findings:

* Infants (age 6 months) whose mothers reported fever during second trimester became significantly more distressed around new situations or strange adults

* Preschool children (age 5) whose mothers reported fever during the second trimester could not attend to play and learning materials as long as their peers, and are more socially inhibited in the presence of strange adults or children

* At age 12, the children are at greater risk for reduced academic performance and decreased ability to focus on tasks.

"There is a significant body of research that investigates the association between influenza during the second trimester of pregnancy and later development of psychiatric disorders in offspring, including schizophrenia," said Dombrowski. "However, the influenza virus does not appear to cross the placental barrier. As a result, researchers have speculated that fever might be the mechanism of adverse impact. Our study is the first to investigate the possibility that maternal fever during pregnancy may be linked to later psychological, behavioral, and academic outcomes.

Since his research focuses on child development, this study is "a natural progression" for Dombrowski. He is currently compiling a literature review on the impact of prenatal influenza exposure and how it relates to schizophrenia. Dombrowski and his colleagues obtained data for the study from the Helsinki Longitudinal Project, a prospective study of early childhood temperament. The sample consisted of 6,401 children born between July 1, 1975, and June 30, 1976, in Helsinki, and two adjacent suburbs. The sample size was adjusted by eliminating data for one twin or each twin pair " producing a final size of 6,388 children.

The Helsinki data set is one of the first longitudinal data sets that allows for an investigation of how prenatal and early childhood factors impact later development.

Since there has been extensive research on first-trimester prenatal viral exposure and its link to severe abnormalities, Dombrowski maintains that more subtle indicators of academic or psychological problems later in childhood tend to be overshadowed.

"Our investigation may not be regarded as a cure for such diseases as cancer but it contributes significantly to understanding the less tangible environmental factors that influence a child's development," said Dombrowski.

As a testament to the contribution of this study, Dr. Jose Cordero, assistant surgeon general and director of the National Center on Birth Defects and Developmental Disabilities at the Centers for Disease Control and Prevention, prepared a commentary on Dombrowski's hypothesis.

"Perhaps physicians will use this information to caution women to avoid situations which might put them at risk for viral infections if at all possible," said Dombrowski. "In addition, it might be advisable for women who will be in the second or third trimester of pregnancy during flu season to obtain a flu vaccine."