The cynomolgus monkey as a model for developmental toxicity studies: variability of pregnancy losses, statistical power estimates, and group size considerations.

Background: This work evaluates pregnancy and infant loss in 1,069 vehicle-treated cynomolgus monkeys from 78 embryo-fetal development (EFD) studies and 14 pre-postnatal development (PPND) studies accrued during 1981-2007.

Methods: Losses were analysed by survival function and hazard ratio using logistic regression for influence of year, study type (e.g.