Methodological approaches for animal studies

Other tests can reveal effects indicative of potential reproductive toxicity. Examples include the dominant lethal test, fertility assessment by continuous breeding, repeated-dose toxicity testing, and cancer studies where the gonads are subjected to pathological examination. These tests, however, provide information only on effects after dosing adult animals and are therefore not addressed below. 

OECD TG 414 Prenatal Developmental Toxicity Study (OECD, 2001a) At least from implantation to 1 or 2 days before expected birth 3 dose levels plus control n = 20 pregnant females Implantation, resorptions Fetal growth Morphological variations and malformations + malformations are assessed in all fetuses - the dosing period includes only the prenatal period - the effects assessment includes only effects in fetuses 

OECD TG 421 and TG 422 Reproduction/ Developmental Toxicity Screening Test (with or without the Combined Repeat Dose Toxicity Study) From 2 weeks prior to mating until at least day 4 postnatally 3 dose levels plus control n = 8-10 pregnant females Fertility Pregnancy length and birth Fetal and pup growth and survival until day 3 + short-term test - limited exposure period - limited number of end-points - limited sensitivity due to number of animals 

central nervous system PND, postnatal day PNS, peripheral nervous system TG, Test Guideline 

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