Reproductive and developmental toxicity studies of silicone elastomer Q7-2423/Q7-2551 in rats and rabbits

The purpose of these studies was to assess the potential adverse effects of silicone breast implant envelope elastomer on general reproduction and fetal development in rats and rabbits. One control and one treatment group of 30 male and 30 female Charles River CD rats and 25 inseminated New Zealand white rabbits per group were used in the one-generation reproductive and developmental toxicity studies, respectively. Two 1.2-cm discs of silicone elastomer were subcutaneously implanted in one site in the left flank and one site in the right-flank of the treated group of rats, while four 2.5-cm discs were implanted in two sites in the left flank and two sites in the right flank of the treated group of rabbits. The size of the elastomer implants was chosen to approximate the expected body burden of women with breast implants. The control animals in both studies received subcutaneous implantation of either 1.2- or 2.5-cm discs of polyethylene of the same number in the same locations. The control and test articles were implanted in the male and female rats at 61 and 47 days, respectively, prior to mating (in the rat reproduction study) and approximately 42 days prior to insemination of female rabbits (in the rabbit developmental toxicity study). Subcutaneously implanted discs of silicone breast implant envelope elastomer did not induce maternal or developmental toxicity before or during pregnancy or during lactation, did not cause any adverse effects on the parents or neonates, and did not impair reproductive performance in the rat reproduction study. No maternal toxicity or adverse developmental effects, including teratogenicity, were observed in the treated groups in the rabbit developmental toxicity study.