| Title | Register data suggest lower intelligence in men born the year after flu pandemic. | | Author(s) | Eriksen W, Sundet JM, Tambs K | | Institution | Division of Mental Health, Norwegian Institute of Public Health, Oslo, Norway. w-bjarer@online.no | | Source | Ann Neurol 2009 Sep; 66(3):284-9. | | MeSH | Adult
Brain
Cognition Disorders
Disease Outbreaks
Female
Fetal Diseases
Health Surveys
Humans
Infant, Newborn
Infant, Small for Gestational Age
Influenza, Human
Intelligence Tests
Male
Maternal Exposure
Mental Retardation
Military Personnel
Norway
Pregnancy
Pregnancy Complications, Infectious
Prenatal Exposure Delayed Effects
Registries
Risk Factors
Socioeconomic Factors
| | Abstract | OBJECTIVE: To test the hypothesis that prenatal exposure to the Hong Kong flu, an influenza pandemic that haunted Europe during winter 1969 to 1970, was associated with reduced intelligence in adulthood.
METHODS: Data from the Medical Birth Register of Norway were linked with register data from the National Conscript Service. The sample comprised all registered boys born alive in single birth after 37 to 43 weeks' gestation during 1967 to 1973 (n = 205,634). Intelligence test scores, recorded at military conscription, were available for 182,913 individuals.
RESULTS: The mean intelligence score increased from one birth year to another, except for a downturn in 1970. The birth year 1970 was inversely associated with intelligence score (-0.03 standard deviation [SD]; p < 0.001) after adjustments for birth characteristics, parental characteristics, and the trend of increasing scores over the 7 birth years. Analyses with the sample stratified by birth month showed that the inverse association between the birth year 1970 and intelligence score was significant only among men born in July (-0.04 SD; p = 0.049), August (-0.05 SD; p = 0.013), September (-0.09 SD; p < 0.001), and October (-0.06 SD; p = 0.008). Thus, the intelligence scores of the men born 6 to 9 months after the epidemic were lower than the mean values for the men born in the same months a few years before or after.
INTERPRETATION: Early prenatal exposure to the Hong Kong flu may have interfered with fetal cerebral development and caused reduced intelligence in adulthood. | | Language | eng | | Pub Type(s) | Journal Article
| | PubMed ID | 19798723 |
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