Undernutrition is known to lower fertility in female rodents and slow the development of their offspring. How far it confounds the interpretation of reproductive findings in regulatory toxicology studies, though, remains controversial. Misinterpreting these findings can lead to unnecessary precautionary classification, with significant consequences for industry under hazard-based regulation.
This case study comes from an ongoing EU REACH assessment. It analysed GLP-compliant OECD 422 studies on 15 related Rosin (CAS 8050-09-7) and derivative substances, using multiple linear regression to relate maternal undernutrition to reproductive outcomes. Treated females ate less and gained less weight, and these reductions correlated significantly with lower corpora lutea counts and slower pup growth. A bespoke pair-fed OECD 421 study then gave control animals exactly the same reduced food intake as Rosin-treated animals. Their offspring were biologically and statistically indistinguishable from those of the Rosin-treated females.
The results show that the impaired offspring development is a non-specific, secondary consequence of maternal undernutrition. Further work is needed to establish whether the fertility effects share the same cause. More broadly, the study shows that levels of undernutrition commonly seen in toxicology studies can affect reproductive outcomes in a standard regulatory study design.
Author
Michael McMahon
EUROTOX 2026, Poster P28-14 (Poster Viewing 2, Reproductive and Developmental Toxicology).