Reduced auditory acuity in rat pups from excess and deficient omega-3 fatty acid consumption by the mother.

Consumption of the nutrients omega-3 fatty acids (omega-3 FA) during pregnancy and lactation is considered beneficial to fetal and infant development. It may also reduce the incidence and severity of preterm births by prolonging gestational length. However several recent human and animal studies have reported that over-supplementation with omega-3 FA, especially in the form of fish oil, can have adverse effects on fetal and infant development and the auditory brainstem response (ABR). Our goal was to assess further the effects of omega-3 FA excess and deficiency during pregnancy and lactation on the offspring's auditory acuity as evidenced by their ABR thresholds. Female Wistar rats were given diets that were either deficient, adequate (control) or excess in omega-3 FA from day 1 of pregnancy through lactation. The offspring were ABR-tested at the postnatal age of 24 days. The rat pups in the Excess treatment condition had significantly elevated (worse) ABR thresholds, postnatal growth restriction, and a trend for increased postnatal mortality in comparison to the Control group. The Deficient group was intermediate. In conclusion, excess or deficient amounts of omega-3 FA during pregnancy and lactation in the laboratory rat adversely affected the offspring's auditory acuity. Postnatal thriving was also adversely affected. Consuming or administering large or inadequate amounts of omega-3 FA during pregnancy and lactation seems inadvisable because of the potential for adverse effects on infant development.