The Study On The Levels Of AFP,f-β-hCG,uE₃ In Maternal Serum At The Second Trimester As Predicting Indicators Of Placenta Accreta Spectrum

ObjectivesTo investigate the value of alpha-fetoprotein（AFP）,free beta human chorionic gonadotropin（f-β-hCG）and unconjugated estrol（uE₃）in serum of pregnant women at the second trimester as predicting indicators of placenta accreta spectrum（PAS）.MethodsSingle pregnancy pregnant women who terminated their pregnancies by cesarean section in Maternal and Child Health Hospital Affiliated to Anhui Medical University from December 2019 to December 2020,who underwent aneuploidy screening in this hospital during the second trimester(15-20⁺⁶weeks)and had at least one previous cesarean section were selected as the study population.Patients with eclampsia and other complications were excluded.Maternal basic information,the results of serum biomarkers at the second trimester,the clinical data and the pregnancy outcomes were collected.According to the intraoperative observations at the time of delivery and/or postoperative pathology,patients were divided into placenta accreta spectrum group（PAS group）and non-placenta accreta spectrum group（non-PAS group）.The differences of data were analyzed by case-control study.Analyze independent risk factors affecting placenta accreta spectrum.Explore the value of each serum biomarker alone or in combination in predicting placenta accreta spectrum and judging the degrees and prognosis.Results1.The differences between 2 groups in age,the ratio of previous pregnancies≥2 times,previous cesarean sections≥2 and previous delivery times≥2 were not stasistically significant（all P>0.05）.The ratio of patients with placenta previa in the non-PAS group was lower than that in the PAS group（P<0.05）.2.There was no significant difference in the gestational age of aneuploidy screening blood collection,f-β-hCG,uE₃and uE₃MoM at the second trimester(15-20⁺⁶weeks)between the 2 groups（all P>0.05）.The maternal serum AFP,AFP-MoM and f-β-hCG MoM levels at the second trimester(15-20⁺⁶weeks)of non-PAS group were lower than those of PAS group（all P<0.05）.3.The multivariate unconditional logistic regression analysis showed that placenta previa（OR=14.663,95%CI:6.085-35.334,P<0.01）,high AFP MoM（OR=1.422,95%CI:1.201-1.685,P<0.01）and high f-β-hCG MoM（OR=1.812,95%CI:1.054-3.116,P<0.05）were independent risk factors for PAS.4.AFP MoM and f-β-hCG MoM at the second trimetion(15-20⁺⁶weeks)were used as predictive variables of PAS separately and in combination to draw ROC curves.The areas under the curve were 0.829,0.604 and 0.847.When the best prediction value was taken,the Yoden index was 0.538,0.209 and 0.598.The efficiency of combined prediction is higher than that of each index alone.5.The gestational age at delivery of the non-PAS group was bigger than that of the PAS group,the rate of premature birth,postpartum hemorrhage,anrepartum hemorrhage,the ratio of low birth weight and postpartum blood loss in the non-PAS group were lower than those in the PAS group（all P<0.05）.The weight of newborn between the 2 groups didn’t have statistically significant difference（P>0.05）.6.In the PAS group,AFP MoM at the second trimester of placenta percreta group（n=4）was higher than that in the placenta accreta group（n=20）and the placenta increta group（n=10）（both P<0.05）.While the latter 2 groups had no significant differences（P>0.05）.There was no statistically significant difference in the f-β-hCG MoM at the second trimester among the three groups（P>0.05）.7.In the PAS group,AFP MoM at the second trimester of postpartum hemorrhage group was（2.06±0.95）,which was higher than that in the non-postpartum hemorrhage group（1.26±0.22）（P<0.05）.The f-β-hCG MoM at the second trimester(15-20⁺⁶weeks)of the 2 groups had no statistically significant difference（P>0.05）.Whether premature delivery and anrepartum hemorrhage occurred or not,there were no statistically significant differences in the AFP MoM and f-β-hCG MoM at the second trimester(15-20⁺⁶weeks)（P>0.05）.Conclusions1.Placenta previa,high levels of maternal serum AFP MoM and f-β-hCG MOM at the second trimester(15-20⁺⁶weeks)were independent risk factors for PAS.2.Maternal serum AFP MoM and f-β-hCG MoM at the second trimester(15-20⁺⁶weeks)have predictive value for placenta accreta spectrum.Moreover,the combined predictor established by the two indexs is better than each single index in predicting placenta accreta spectrum.AFP MOM had a higher distribution in both PAS patients with postpartum hemorrhage and placenta percreta.