Influence of environmental tobacco smoke during pregnancy on plasma interleukin-6, -10 and C-reactive protein in neonatal umbilical cord

Abstract

Objective To study the influence of environmental tobacco smoke(ETS) during pregnancy on plasma inflammatory factors interleukin(IL)-6, -10, and C-reactive protein(CRP) contents in neonatal umbilical cord. Methods A total of 352 cases of singleton pregnant women and their 352 cases of neonates in Shenzhen Shajing Affiliated Hospital of Guangzhou Medical University from October 2013 to October 2015, were chosen as study objects. According to questionnaire survey results of whether the maternal had ETS or not during pregnancy, the pregnant women and their newborns were divided into ETS group(ETS) and control group(no ETS). Among 352 cases of maternal who were inquired about the ETS situation during pregnancy as well as the general clinical data and the gender of their newborns.Detected plasma IL-6、-10 and CRP contents of neonatal umbilical cord by enzyme-linked immunosorbent assay method. Statistical comparison of: ①The differences between two groups in general clinical data of maternal and gender constituent ratio of newborns; ②The differences between two groups of newborns, and pairwise between newborns of mild or severe of ETS maternal and newborns of no ETS maternal in neonatal umbilical cord blood plasma inflammatory factors contents; ③The differences between preterm infants and term infants in each group or between two groups of neonatal umbilical cord blood plasma inflammatory factors contents.The study protocol was approved by the Ethical Review Board of Investigation in Human Being of Shenzhen Shajing Affiliated Hospital of Guangzhou Medical University.Informed consent was obtained from each participant. Results ①The questionnaire survey recovery rate was 100.0%.There were 174 cases of ETS maternal or their newborns, including 74 cases of severe ETS maternal and 100 cases of mild ETS maternal, and there were 178 cases of no ETS maternal or their newborns. The constituent ratio of maternal cultural level between two groups has significant difference(χ2=8.099, P=0.017), maternal cultural level of ETS group was lower than that of control group. There were no significant differences between two groups of maternal in maternal age and gestational age, constituent ratio of obesity degree, family monthly income per capita, maternal type and alcohol drinking during pregnancy, and gender constituent ratio of newborns(P>0.05). ②The IL-6 and CRP contents of neonatal umbilical cord blood plasma in ETS group were higher than those of control group, but IL-10 content was lower than that of control group, and the differences were statistically significant(P<0.05); Plasma IL-6 content of neonatal umbilical cord blood gradually increased with maternal ETS aggravated, and the differences were statistically significant (P<0.05); ③Plasma IL-6 and CRP contents of neonatal umbilical cord blood of preterm infants were higher, while IL-10 content was lower than those of term infants in ETS group, and the differences were statistically significant(P<0.05); Plasma IL-6 content of neonatal umbilical cord blood of preterm infants was higher than that of term infants in control group, and the difference was statistically significant(P<0.05); Plasma IL-6 and CRP contents of neonatal umbilical cord blood of preterm infants in ETS group were higher, while IL-10 content was lower than those of preterm infants in control group, and the differences were statistically significant(P<0.05); Plasma IL-6 content of neonatal umbilical cord blood of term infants in ETS group were higher than that of term infants in control group, and the difference was statistically significant(P<0.05). Conclusions Maternal has ETS during pregnancy can affect the inflammatory reaction of newborns, and increase the risk of preterm birth. Key words: Tobacco smoke pollution; Environmental tobacco smoke; Pregnancy; Interleukin-6; Interleukin-10; Pregnant women; Infant, newborn