Does Being Born Slightly Early or Slightly Late Affect Epilepsy Risk?

February 14, 2019

Results of this Swedish study may help guide decisions about monitoring and induction of labor.

RESEARCH UPDATE

Infants born over 1 week early or over 1 week late may be at increased risk for epilepsy compared with term infants born at 39 or 40 weeks’ gestational age, according to a study recently published online in PLoS One.1

“[T]hese data could provide useful information to help women and caregivers make decisions with regard to the timing of induction of labour. It would also appear prudent to offer enhanced surveillance to these women in order to minimize any potential impact,” wrote first author David Odd, MBChB, MD, of the University of Bristol (Bristol, UK), and colleagues.

Recent research has suggested that early-term infants born at weeks 37 or 38 may be at increased risk for neurodevelopmental problems. Less research has been done on neurodevelopmental outcomes in late-term infants born at 41 weeks or after. But these infants are at increased risk for infection, stillbirth, and complications related to large birth size, such as shoulder dystocia. Research provides little guidance on which late-term infants may benefit from increased monitoring and induction of labor.

To provide more evidence, researchers analyzed data from 1,030,168 infants born without birth defects in Sweden between 1983 and 1993. By linking information in the Swedish Birth Register to national databases on health insurance, social insurance, and inpatient records, they compared disability, child mortality before age 5, and epilepsy diagnosis before age 20 for infants born at early term (37/38 weeks), term (39/40 weeks), and late term (41+ weeks). Results were adjusted for maternal age, occupation, and education, as well as infant sex, primiparity, maternal or infant infection, birth weight, and cesarean section.

Results and take-home points >

The results

Adjusted results showed that the risk of epilepsy was significantly increased both for early-term (odds ratio [OR], 1.19; 95% confidence interval [CI], 1.11-1.29; P < .0001), and for late-term infants (OR, 1.13; 95% CI, 1.06-1.22; P = .0004). Early-term and late-term infants also had a significantly increased risk of being eligible for disability payments (OR, 1.20; 95% CI, 1.16-1.24; P < .0001; and OR, 1.05; 95% CI, 1.01-1.08; P = .0053, respectively).

However, while the risk of child death was increased by 42% in early-term infants (OR, 1.42; 95% CI, 1.30-1.55; P < .0001), results were not significant for late-term infants (OR, 1.08; 95% CI, 0.99-1.18; P = .093).

Results also suggested a U-shaped curve. The lowest risk of epilepsy appeared to be at term, while risk increased in both directions further away from term.

In early- and late-term infants, there was no link between epilepsy and low birth weight (P = .5083), multiple birth (P = .7208), maternal age (P = .7986), cesarean section (P = .6744), or preeclampsia (P = .3096).

The authors mentioned several limitations. Notably, because the study used administrative data, the underlying causes for increased risk of epilepsy among early- and late-term infants cannot be determined.

Take-home points

• Swedish researchers found that infants born at early or late term may be at increased risk for epilepsy and disability

• Early-term infants but not late-term infants were at increased risk for death before age 5

• Results add to evidence that may be used to guide treatment decisions about monitoring and induction of labor

References:

1. Odd D, Glover Williams A, Winter C, et al. Associations between early term and late/post term infants and development of epilepsy: a cohort study. PLoS One. 2018;13:e0210181. doi: 10.1371/journal.pone.0210181. eCollection 2018.