ABSTRACT
Objective:To investigate the predictive value of maternal peripheral blood fetal DNA, creatine kinase (CK), and alpha-fetoprotein (AFP) in pregnant women with placenta previa complicated with adhesion or implantation.Methods:From April 2018 to April 2019, 72 patients with placenta previa confirmed by cesarean section in Chengde Central Hospital were retrospectively collected. Among them, 23 patients complicated with placental adhesion were enrolled in the placenta adhesion group, 19 patients complicated with placenta implantation were in the placenta implantation group, and 30 patients with simple placenta previa were in the simple placenta previa group. The amount of fetal DNA, CK and AFP in maternal peripheral blood were measured at 20 to 27 weeks of gestation. The general data of the three groups, the amount of fetal DNA in maternal peripheral blood, CK and AFP were compared. The value of the amount of fetal DNA, CK, and AFP in maternal peripheral blood for predivting placenta previa were analyzed. At the same time, the incidence of adverse pregnancy outcomes was counted, and patients were divided into adverse pregnancy outcomes group and good pregnancy outcomes group according to pregnancy outcomes. The fetal DNA amount, CK and AFP levels in the maternal peripheral blood of the two were compared, and the factors affecting the adverse pregnancy outcome of placenta previa were analyzed.Results:The levels of fetal DNA, CK and AFP in the maternal peripheral blood of the placenta implantation group were significantly higher than those of the placenta adhesion group and the simple placenta previa group: (1 018.96 ± 442.15) copies/ml vs. (659.27 ± 320.26) copies/ml and (390.64 ± 102.53) copies/ml , (103.54 ± 26.39) U/L vs. (88.30 ± 20.65) U/L and (62.78 ± 15.84) U/L, (319.65 ± 62.14) μg/L vs. (284.62 ± 55.96) and (232.64 ± 48.62) μg/L, and the difference was statistically significant ( P<0.01). The amount of fetal DNA in maternal peripheral blood was positively correlated with CK and AFP ( r = 0.899 and 0.769, P<0.01), and CK was positively correlated with AFP ( r = 0.782, P<0.01). The AUC of maternal peripheral blood fetal DNA in predicting placenta previa complicated with placenta adhesion was 0.842, and the sensitivity and specificity were 78.26% and 83.33% respectively. The levels of fetal DNA, CK and AFP in maternal peripheral blood of patients with adverse pregnancy outcomes were higher than those of patients with good pregnancy outcomes: (928.64 ± 257.73) copies/ml vs. (460.02 ± 188.95) copies/ml, (105.83 ± 26.88) U/L vs. (66.33 ± 20.39) U/L and (292.52 ± 58.39) μg/L vs. (259.29 ± 42.65) μg/L, and the difference was statistically significant ( P<0.05). Placenta adhesion, placenta implantation, postpartum hemorrhage, maternal peripheral blood fetal DNA, CK and AFP levels were influential factors for the adverse pregnancy outcome of placenta previa ( OR = 3.544, 4.183, 3.413, 3.222, 3.109 and 3.313, 95% CI 1.905 to 6.593, 2.401 to 7.286, 1.832 to 6.359, 1.729 to 6.005, 1.659 to 5.827 and 1.831 to 5.994, P<0.01). Conclusions:The amount of fetal DNA, CK and AFP in maternal peripheral blood have a certain predictive value in placenta previa complicated with placental adhesion or implantation, and are closely related to the pregnancy outcome of patients with placenta previa. Early detection of the above indicators will help clinically to formulate reasonable intervention measures and promote the improvement of pregnancy outcomes.