FAILURE OF MONOETHYLHEXYL PHTHALATE TO CAUSE TERATOGENIC EFFECTS IN OFFSPRING OF RABBITS

Female rabbits with an average body weight of 3.9 ± 0.5 kg were artificially inseminated and subsequently injected with varying doses of Na-monoethylhexyl phthalate (MEHP) (1.14, 5.69, or 11.38 mg/kg daily × 13, iv) beginning on the sixth day of gestation. On the 30th day, fetuses were removed by Cesarian section. Sex ratios, fetal weights, and size of litters were unaffected by MEHP regardless of the doses given. The incidence of live fetuses in the two control groups was 94% while in the 1.14 mg/kg dose it was 89%; 5.69 mg/kg, 84%; and 11.38 mg/kg, 77%. MEHP treatment failed to affect the size of the fetuses as measured by crown-rump or transumbilical measurements. The number of corpora lutea and resorptions in MEHP-treated groups was not significantly different from the number in the control groups. A higher maternal death rate was noted in rabbits given the 5.69 and 11.38 mg/kg doses (22 and 33%, respectively). However, there were no differences in the weights of adrenals, liver, kidneys, heart, or lungs of those animals continuing to term when compared to organs from animals in control groups. Skeletal examinations revealed slight variations in the 13th rib, and in the 5th and 6th sternal buttons in fetuses from both the control and MEHP-treated groups. Visceral examination of fetuses failed to reveal any differences between those from phthalate-treated groups and those from control groups. © 1979.