Guidance on the selection of cohorts for the extended one-generation reproduction toxicity study (OECD test guideline 443)

Regul Toxicol Pharmacol. 2016 Oct;80:32-40. doi: 10.1016/j.yrtph.2016.05.036. Epub 2016 May 28.


The extended one-generation reproduction toxicity study (EOGRTS; OECD test guideline 433) is a new and technically complex design to evaluate the putative effects of chemicals on fertility and development, including effects upon the developing nervous and immune systems. In addition to offering a more comprehensive assessment of developmental toxicity, the EOGRTS offers important improvements in animal welfare through reduction and refinement in a modular study design. The challenge to the practitioner is to know how the modular aspects of the study should be triggered on the basis of prior knowledge of a particular chemical, or on earlier findings in the EOGRTS itself, requirements of specific regulatory frameworks notwithstanding. The purpose of this document is to offer guidance on science-based triggers for these extended evaluations.

Keywords: Cohorts; Developmental toxicity; EOGRTS; Extended one-generation reproductive toxicity study; Fertility; Rat; Reproduction; Triggers.

Publication types

  • Guideline

MeSH terms

  • Animals
  • Female
  • Fertility / drug effects*
  • Humans
  • Immune System / drug effects
  • Immune System / growth & development
  • Male
  • Models, Animal
  • Nervous System / drug effects
  • Nervous System / growth & development
  • Organisation for Economic Co-Operation and Development* / standards
  • Rats
  • Reproduction / drug effects*
  • Risk Assessment
  • Toxicity Tests / methods*
  • Toxicity Tests / standards