Consuming omega-3 fatty acids (ω-3 FA) during pregnancy and lactation is beneficial to fetal and infant development and might reduce the incidence and severity of preterm births by prolonging pregnancy. Consequently, supplementing maternal diets with large amounts of ω-3 FA is gaining acceptance. However, both over-and under-supplementation with ω-3 FA can harm offspring development. Adverse fetal and neonatal conditions in general can enhance age-related neural degeneration, shorten life span and cause other adult-onset disorders. We hypothesized that maternal over-and under-nutrition with ω-3 FA would shorten the offspring's life span and enhance neural degeneration in old adulthood. To test these hypotheses, female Wistar rats were randomly assigned to one of the three diet conditions starting from day 1 of pregnancy through the entire period of pregnancy and lactation. The three diets were Control ω-3 FA (ω-3/ω-6 ratio ~ 0.14), Excess ω-3 FA (ω-3/ω-6 ratio ~ 14.5) and Deficient ω-3 FA (ω-3/ω-6 ratio ~ 0% ratio). When possible, one male and female offspring from each litter were assessed for life span and sensory/neural degeneration (n=15 litters/group). The Excess offspring had shorter life spans compared to their Control and Deficient cohorts (mean±SEM=506±24, 601±14 and 585±21 days, p≤0.004) when the study terminated on postnatal day 640. The Excess offspring had a higher incidence of presbycusis than the Control and Deficient groups (33.3, 4.3 and 4.5%, p=0.011) and a persistence of other sensory/ neurological abnormalities and lower body weights in old adulthood. In conclusion, ω-3 FA overnutrition or imbalance during pregnancy and lactation had adverse effects on life span and sensory/ neurological function in old adulthood. The adverse outcomes in the Excess offspring were likely due to a "nutritional toxicity" during fetal and/or neonatal development that programmed them for life-long health disorders. The health implication is that consuming or administering large amounts Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Conflicts of interestThere were no conflicts of interest. NIH Public Access

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Background Fetal Alcohol Syndrome is a leading cause of neurodevelopmental impairments (NDI) in developed countries. Sensory deficits can play a major role in NDI, yet few studies have investigated the effects of prenatal alcohol exposure on sensory function. In addition, there is a paucity of information on the life-long effects of prenatal alcohol exposure. Thus, we sought to investigate the effects of prenatal alcohol exposure on auditory function across the life span in an animal model. Based on prior findings with prenatal alcohol exposure and other forms of adverse prenatal environments, we hypothesized that animals prenatally exposed to alcohol would show an age-dependent pattern of (A) hearing and neurological abnormalities as post-weanling pups, (B) a substantial dissipation of such abnormalities in young adulthood, and (C) a resurgence of such abnormalities in middle-aged adulthood. Method Pregnant rats were randomly assigned to an untreated control (CON), a pair-fed control (PFC) or an alcohol treated group (ALC). The ALC dams were gavaged with 6 mg/kg alcohol daily from gestation day (GD) 6 to 21. The PFC dams were gavaged daily from GD6-21 with an isocaloric and isovolumetric water-based solution of Maltose-Dextrins and pair-fed to the ALC dams. The CON dams were the untreated group to which the ALC and CON groups were compared. Hearing and neurological functions in the offspring were assessed with the Auditory Brainstem Response (ABR) at the postnatal ages of 22, 220 and 520 days of age. Results & Conclusions In accord with our hypothesis, ABR abnormalities were first observed in the post-weanling pups, largely dissipated in young adulthood, and then resurged in middle-aged adulthood. This age-related pattern suggests that the ALC pups had a developmental delay that dissipated in young adulthood and an enhanced age-related deterioration that occurred in middle-aged adulthood. Such a pattern is consistent with the fetal programming hypothesis of adult-onset diseases (the Barker Hypothesis). Our findings have important clinical implications for the assessment and management of (A) childhood hearing disorders and their co-morbidities (i.e., speech-and-language, learning, and attention deficit disorders) and (B) enhanced age-related hearing and neurological degeneration in middle-aged adulthood that can result from prenatal alcohol exposure. We recommend hearing evaluation be a part of any long-term follow-up for FAS patients and patients exposed to any adverse prenatal environment.

Consumption of the nutrients omega-3 fatty acids (ω-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 ω-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 ω-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 ω-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 ω-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 ω-3 FA during pregnancy and lactation seems inadvisable because of the potential for adverse effects on infant development.

Consuming omega-3 fatty acids (ω-3 FA) during pregnancy and lactation benefits fetal and infant brain development and might reduce the severity of preterm births by prolonging pregnancy. However, diets that are relatively rich in ω-3 FA can adversely affect fetal and infant development and the auditory brainstem response (ABR), a measure of brain development and sensory function. We previously examined the offspring of female rats fed excessive, adequate or deficient amounts of ω-3 FA during pregnancy and lactation. The 24-day-old offspring in the Excess group, compared to the Control group, had postnatal growth retardation and poor hearing acuity and prolonged neural transmission times as evidenced by the ABR. The Deficient group was intermediate. The current study followed these offspring to see if these poor outcomes persisted into young adulthood. Based on prior findings, we hypothesized that the Excess and Deficient offspring would "catch-up" to the Control offspring by young adulthood. Female Wistar rats received one of the three diet conditions from day 1 of pregnancy through lactation. The three diets were the Control ω-3 FA condition (ω-3/ ω-6 ratio ~ 0.14), the Excess ω-3 FA condition (ω-3/ω-6 ratio ~ 14.0) and Deficient ω-3 FA condition (ω-3/ω-6 ratio ~ 0% ratio). The Control diet contained 7 % soybean oil; whereas the Deficient and Excess ω-3 FA diets contained 7% safflower oil and 7% fish oil, respectively. One male and female offspring per litter were ABR-tested as young adults using tone pip stimuli of 2, 4, 8 and 16 kHz. The postnatal growth retardation and prolonged neural transmission times in the Excess and Deficient pups had dissipated by young adulthood. In contrast, the Excess group had elevated ABR thresholds (hearing loss) at all tone pip frequencies in comparison to the Control and Deficient groups. The Deficient group had worse ABR thresholds than the Control group in response to the 8 kHz tone pips only. The Excess group also had ABR amplitude-intensity profiles suggestive of hyperacusis. These results are consistent with the Barker hypothesis concerning the fetal and neonatal origins of adult diseases. Thus, consuming diets that are excessively rich or deficient in ω-3 FA during pregnancy and lactation seems inadvisable because of risks for long-lasting adverse effects on brain development and sensory function.