Evaluation of the teratogenicity of morphine sulfate administered via a miniature implantable pump

A technique has been developed for the implantation of miniature infusion pumps in pregnant mice with minimal teratogenic and toxic side effects. In 7- to 10-day pregnant CF-1 mice receiving constant low doses of morphine sulfate via the infusion pump, the results, including fetal weight reduction and various skeletal and soft tissue abnormalities, were similar to those reported in previous investigations using single injections.