The Protective Effect Of Vitamin C Supplementation On Fetal Growth Restriction And Placental Developmental Damage Caused By Arsenic Exposure During Pregnancy

Background: Fetal growth restriction is a common complication of pregnancy and is associated with a variety of adverse p pregnancy outcomes.Studies have shown that environmental factors are closely related to adverse pregnancy outcomes.Arsenic exists widely in nature and seriously endangers human health.Arsenic contamination of drinking water has become one of the most important public health problems in the world.Epidemiological and animal studies have shown that arsenic exposure during pregnancy causes fetal growth restriction and placental developmental damage.Relevant studies have shown that Vitamin C can reduce the level of reactive oxygen species in the body to reduce oxidative stress response.Objective: To investigate the effects of vitamin C supplementation on fetal growth restriction and placental developmental damage caused by arsenic exposure during pregnancy.Methods: The main purpose of this study was to investigate the effects of vitamin C supplementation on fetal growth restriction and placental damage caused by arsenic exposure during pregnancy through animal experiments.Healthy clean grade ICR(CD-1)mice(female weight: 28-30 g,male weight: 38-40g)at the age of 8 weeks were selected.The feeding environment maintained a 12-hour circadian rhythm,and the temperature was kept between 20-25 ℃ and the humidity was controlled between50±5 %.All mice ate and drank freely,and were kept in a clean and comfortable environment.After the purchase of mice,the adaptive feeding began for one week.Female mice and male mice were placed together in a ratio of 4:2 at 21:00 in the evening for mating.Female mice were examined at 7:00 am the next Day.Female mice with vaginal plug were considered to have mated successfully and were marked as pregnant mice,and the day was recorded as the 0 day of pregnancy(GD0).Pregnant mice were divided into four groups randomly : control(CTRL),As,VC and VC+As groups.In the CTRL and VC groups,pregnant mice drank ultrapure water.In the As and VC+As groups,pregnant mice drank ultrapure water containing Na As O2(15 mg/L).Besides,In the VC and VC+As groups,pregnant mice were given VC(30mg/kg)by drinking water intragastric administration.Similarly,In the CTRL and As groups,mice were given equal volume of ultrapure water daily by intragastric administration.All pregnant mice were sacrificed on GD18.The number of absorbed fetuses,dead fetuses,live fetuses,and the sex,the weight of live fetuses,the crown-rump of live fetuses,the weight of placenta and the diameter of placenta were recorded,and the fresh placenta tissues of mice were collected for H&E staining to observe the pathological structure.Results:(1)Among the four groups,there were no significant differences in the average number of absorbed fetuses,dead fetuses,live fetuses,the sex ratio,the crown-rump of live fetuses(p > 0.05).However,compared with CTRL group,the birth weight of the offspring of pregnant mice exposed to As through drinking water during the whole pregnancy was lower than that of the CTRL group(p < 0.05).At the same time,the birth weight of fetuses in VC+As group was increased compared with that in As group after vitamin C supplementation throughout pregnancy(p < 0.05).(2)Although there were no statistically significant differences in placental weight and placental diameter between the four groups(p > 0.05),H&E staining results of placental pathology showed that,compared with the CTRL group,the ratio of the area of placental labyrinth zone to the total placental area decreased.Moreover,after vitamin C supplementation throughout pregnancy,the percentage of the labyrinth zone to the total placental area increased in the VC+As group compared with the As group.Conclusions: Vitamin C supplementation during pregnancy has a protective effect on fetal growth restriction and placental developmental damage caused by arsenic exposure.