Age at first febrile seizure correlates with perinatal maternal emotional symptoms

Prenatal exposure to stress and fever are factors lowering seizure threshold in animal models. The fever effect on seizure threshold is well documented in human infants, however the associations between maternal perinatal stress and infants' susceptibility to seizures is unknown. This is the first study in humans to investigate longitudinally, whether in humans, the effect of maternal perinatal emotional symptoms such as stress, anxiety and depression that may trigger a biological stress response on age at first seizure occurrence.

The study sample is a subgroup drawn from a longitudinal follow up cohort (3D cohort study: Design, Develop, Discover, N=2366 mother-infant dyads). Twenty-nine otherwise healthy infants who had a febrile seizure (FS) episode before the last follow-up visit (around 24 months of age) were studied. Mothers completed questionnaires regarding their emotional health at each pregnancy trimester and at three months postpartum. The link between maternal emotional symptoms and infant age at first FS was assessed through correlations and multiple regressions.

We found that maternal anxiety symptoms during the second trimester of pregnancy are linked to the age at first FS (r(23)=-0.459, p=0.021) and explain 21.1% of its variance. Postnatal maternal depression symptoms at 3 months postpartum were also associated with the age at first FS (r(23)=-0.587, p=0.002) and explained an additional 17.6% of variance. Together, the variables explained 38.7% of the variance in age at first FS. Maternal perceived stress symptoms at 3 months postpartum were also linked to the age at first FS (r(23)=-0.418, p=0.038), however, stress did not significantly contribute to the variance of age at first FS..

Our results suggest a link between increased perinatal maternal emotional symptoms and the age at first FS. An earlier age at first FS may be the manifestation of a lower seizure threshold. Early first seizure occurrence is a risk factor for compromised neurological and cognitive development. Further studies should address the mechanisms by which perinatal maternal emotional symptoms may have an impact on seizure threshold in humans.