United Kingdom: regulatory attitudes toward behavioural teratology testing.

In the UK, postnatal evaluation of offspring, extending beyond weight and survival data, is currently only required under the guidelines for testing human medicines. Such testing is carried out as part of fertility studies and, under some circumstances, as part of perinatal studies. In the 10 years of experience since the guideline was introduced, the majority of test data submitted have focused on physical, sensory and motor development of the offspring. More complex behavioural tests of cognitive function are generally only carried out for drugs with therapeutic actions on the central nervous system. Some of the reasons behind the present reluctance to introduce behavioural teratology testing for classes of chemicals other than drugs are discussed.