Prenatal stress and risk of febrile seizures in children a nationwide longitudinal study in Denmark

Purpose The study examined the association between prenatal stress due to bereavement and the resultant risk of febrile seizures in young children. The study hypothesized that those mothers who were exposed to unexpected death within the family, especially those involving children, were more prone to prenatal stress. Participants The study was a population-based cohort study that used the data from the Danish civil registration system from which single children who were born in between 1st of January 1978 until the 31st December 2002 were included in the study. The study children were categorized based on the cause for prenatal bereavement such as those involving the loss of a child, husband, sibling or a parent. Those children who were not exposed to prenatal stress were included under the unexposed category. Method The cohort members were followed from 3 months and the first occurrence of febrile seizure, death or emigration was noted. Those diagnosed with febrile seizures between 3 months to 5 years of age were classified as febrile seizures case. The study was followed up to 5 years of the children or until the closure of the study. The perinatal factors of the mother and the child and socio-demographic factors were obtained from the specific databases. The study population was categorized based on the relationship of the deceased member to the mother and further by the cause of the death. The different periods of fetal development during which the death occurred was also noted. Cox regression model was used to estimate hazard ratios and various factors associated with both prenatal stress and febrile seizures were adjusted with the study results. Result The study found that out of the 1, 431,175 children born during the period, 34,777 mothers had experienced bereavement either during pregnancy or one year prior to gestation. The hazard ratio after adjustment of febrile seizures born to such bereaved mothers was 1.00 compared to that of children who were not exposed to such bereavement and 1.09 in case of loss of a child and 1.02 when it involved the loss of other relatives. The risk did not vary with the cause of death and no increased risk was observed for the different study periods considered. The results were also unaffected by the gender of the children to their optimal birth characteristics such as gestational age and weight. Discussion The study found that the hypothesis that prenatal exposure to stress lead to febrile seizures in early childhood was not significant as the risk for occurrence of seizures was similar in both exposed and unexposed children. Studies have shown that decreased birth weight and age, maternal smoking and alcohol consumption have been associated with increased febrile seizures. Other studies suggest that prenatal exposure to stress and glucocorticoids induce programming of the fetal brain which may result in congenital malformations in the child. However, in this study exposure to severe prenatal stress at different periods of gestation did not cause any significant development of febrile seizures. One major study limitation is the lack of account of hormonal changes within the mother in response to the bereavement. Reference Li, J., Oslen, J., Obel, C., Christensen, J., Hansen Precht, D., amp. M. Vestergaard. (2009). Prenatal stress and risk of febrile seizures in children: A nationwide longitudinal study in Denmark. Journal of Autism and Developmental Disorders, 39 (7): 1047-1052.