Maternal Influenza Shows Association With Increased Risk of Childhood Seizures

Maternal influenza (flu) during pregnancy has been associated with an increased risk of childhood seizure, especially febrile seizures, but not with epilepsy, according to the authors of a study published in JAMA Open Network.¹

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Febrile seizures are the most common type of seizure for children aged 6 months to 5 years, with an incidence of 2% to 5% for children in the United States and Europe. The peak is between 12 to 18 months, and some children might have a singular event, but approximately 30% experience multiple episodes during early childhood. According to the National Library of Medicine, most seizures resolve spontaneously and without complications, but there has been evidence to suggest that some patients are at a higher risk of developing epilepsy or another seizure disorder.²

Epilepsy is categorized as at least 2 seizures that occur more than 24 hours apart. The important features are age, seizure triggers, and comorbidities, which include psychiatric and intellectual dysfunction.³

In the current study, authors noted that maternal bacterial and viral infections during pregnancy have occurred before certain neurological sequelae in children, including epilepsy, and flu has been associated with adverse birth outcomes. Investigators used data from Taiwan’s Maternal and Child Health Database, linking the Taiwan Birth Registration Database, Birth Certificate Application, National Register of Death, and the National Health Insurance Research Database. Further, medical records were from outpatient services, hospitalization documents, and emergency department (ED) visits from January 1, 2004, and December 31, 2013. During the study, children were followed up until December 31, 2020.¹

Mothers who had an outpatient visit, ED visit, or hospitalization with the main diagnosis of flu were in the flu arm, and those in the control group were mothers without flu during pregnancy. They were paired 1:4, according to the study authors. The primary outcome included a diagnosis of any type of seizure during childhood, including epilepsy and febrile seizures. Pregnancy complications, including gestational hypertension, gestational diabetes, preeclampsia or eclampsia, and anemia, were collected.¹

There was a total of 75,835 children (48.1% female) whose mothers (a predominant maternal age of 25 to 29 years old) were diagnosed with flu during the pregnancy and 1,240,272 whose mother did not have flu during pregnancy. Investigators included 303,340 in the control group, with 48.1% being female. The basic demographic characteristics of the mother-child pairings were matched. However, those in the flu group had a higher prevalence of placenta previa or abruption compared with the control group at 1.6% and 1.4%, respectively.¹

Among children whose mothers had flu, 3.2% developed seizures in the follow up period, which had a cumulative risk higher than the control group. Furthermore, the cumulative risk for febrile convulsions was significantly higher in the flu group, but epilepsy did not follow the same trend. The model also showed that covariates, such as maternal age, gestational hypertension, mode of delivery, male child, birthweight, and gestational age, were significant. However, multiple births were not significant, according to the study investigators.¹

REFERENCES

1. Lee Y, Lin Y, Lin C, Lin M. Influenza Infection During Pregnancy and Risk of Seizures in Offspring. JAMA Netw Open. 2024;7(9):e2434935. doi:10.1001/jamanetworkopen.2024.34935

2. Xixis KL, Samanta D, Smith T, et al. Febrile Seizure. [Updated 2024 Jan 19]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan–. Available from: https://www.ncbi.nlm.nih.gov/books/NBK448123/

3. Liman MNP, Al Sawaf A. Epilepsy EEG. [Updated 2023 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK558912/