Effect of monoethylhexyl phthalate on embryo implantation during early pregnancy and fetus development during medium and late pregnancy in the rat

Objective To investigate the effect of monoethylhexyl phthalate on embryo implantation during early pregnancy and fetus development during medium and late pregnancy in rat.Methods Forty pregnant rats were randomized equally into 4 groups consisting of three treatment groups(in which MEHP was administered at 5,25,50 mg/kg,respectively,from 1 to 6 day of pregnancy)and a control group.Other forty pregnant rats were given MEHP from 7 to 20 days of pregnancy,and the grouping methods are the same as former.The pregnant rats were killed by 14 or 21 day of pregnancy.The following results in each group were recorded:embryo implantation cases,food intake and body weight of female rats,the weight of fetal body and placenta,the number of live fetuses,the number of dead fetuses,and the number of absorbed fetuses and fetal malformation cases.Results The food intake and body weight of female rats in MEHP groups had no difference with that in the control group.During early pregnancy,embryo implantation cases in MEHP groups in middle-dose and high-dose(11.11±2.17,9.87±2.41)were lower than that in control group(15.23±1.22,t=5.23,P0.05;t=6.28,P0.01).During medium and late pregnancy,the number of live fetuses,live births cases and the weight of fetal body and placenta in MEHP middle-dose and high-dose groups were lower than that in control group.Absorbed fetal cases and fetal malformation cases in MEHP high-dose groups were higher than that in control group.Conclusions When MEHP has no effects on the food intake and the body weight of female rats,MEHP can affect blastocyst implantation in early pregnancy and embryo development in medium and late pregnancy.These results indicate that MEHP in middle-dose and high-dose may result in early pregnancy loss and adverse to fetal development.