Maternal and early postnatal antibiotic exposure may increase the risk of autism spectrum disorder with regression.

PURPOSE: To analyze if exposure to antibiotics during maternal pregnancy and early postnatal period increases the risk of autism spectrum disorder with regression (ASD-R).

METHODS

A total of 483 children with ASD were categorized into ASD-R and ASD without regression (ASD-NR) groups. The caregivers of children completed questionnaires regarding use of antibiotics during maternal pregnancy and early postnatal period.

RESULTS

There were significantly higher proportions of antibiotic exposure during maternal pregnancy and before age of 2 in the ASD-R group (10.3 % and 44.0 %) compared to the ASD-NR group (2.9 % and 33.1 %). Children with ASD and maternal antibiotic exposure had a higher likelihood of experiencing regression compared to those without exposure (unadjusted OR = 3.81, 95 %CI: 1.67-8.68; adjusted OR = 3.36, 95 %CI: 1.44-7.8). Also, children with ASD who were exposed to antibiotics during early postnatal period had a higher risk of regression, as opposed to those who were not exposed (unadjusted OR = 1.59, 95 % CI 1.08-2.32; adjusted OR = 1.50, 95 % CI 1.01-2.21). Both maternal and early postnatal antibiotic exposure were associated with certain dimensions and total scores of the ABC.

CONCLUSIONS

The ASD-R group had higher rates of antibiotic exposure during both maternal pregnancy and the early postnatal period compared to the ASD-NR group. Maternal and early postnatal antibiotic exposure may be risk factors for regression in children with ASD. Children with ASD who were exposed to antibiotics during maternal pregnancy or the early postnatal period may have more severe core symptoms than those without such history of exposure.