To investigate the predictive value of placental volume, placental area and cervical length for placenta accreta (PAS) in patients with complete placenta previa.

A retrospective study was conducted on 926 patients with complete placenta previa who received regular antenatal examination and delivered in the Affiliated Suzhou Hospital of Nanjing Medical University from January 2016 to December 2023. Among them, 90 patients meeting inclusion criteria with complete placenta previa and PAS were enrolled as the study group, and 90 patients with complete placenta previa without PAS were selected as controls. Maternal age, body mass index (BMI), gravidity and parity, placental area and volume measured by magnetic resonance imaging (MRI), cervical length, gestational age at delivery, intraoperative blood loss, and transfusion volume were compared between groups.

(1) The gravidity [3(3, 4) vs 3(2, 4), Z=2.13] and parity [2(1, 2) vs 2(1, 2), Z=3.06] in the study group was higher than that in the control group, and the difference was statistically significant (P<0.05). The gestational age of delivery in the study group was smaller than that in the control group [(35.51±1.45) weeks vs (36.35±1.77) weeks, t=3.48], and the difference was statistically significant (P<0.05). (2)The operation time [(94.27±33.57) min vs (63.04±27.58) min, t=6.82], blood loss [(2 358.46±537.29)ml vs(1 350.27±364.22)ml, t=14.74] and blood transfusion [(1 725.27±410.55)ml vs (836.58±357.29)ml, t=15.49] in the study group were higher than those in the control group, and the differences were statistically significant(P<0.01). (3)The uterine artery embolization rate (23.22% vs 3.33%, χ²=4.96) in the study group was higher than those in the control group, the difference was statistically significant (P<0.05). The neonatal weight of the study group was lower than that of the control group [(2 419.52±410.27)g vs (2 715.26±385.17) g, t=4.99], and the difference was statistically significant (P<0.05). (4) The placental area [(82.52±12.95) cm² vs (63.50±13.55)cm², t=9.63] and placental volume [(1 003.68±211.52)cm³ vs (812.66±219.50)cm^3, t=5.95] of the study group were higher than those of the control group, and the difference was statistically significant (P<0.05). The cervical length of the study group was smaller than that of the control group [(1.89±0.49) cm vs (2.76±0.54) cm, t=11.32], and the difference was statistically significant (P<0.05). (5) The MRI features of placenta volume, placenta area and cervical length included in this study have certain predictive value for whether patients with placenta accreta, and the AUC of the three MRI features were all >0.80, and the diagnostic value of placenta volume was the largest (AUC=0.88). The combination of three MRI features had high value in the prediction of placenta accreta in placenta previa (AUC=0.93).

The placental volume, placental area and cervical length are effective predictors of PAS in patients with complete placenta previa, aiding obstetricians in preoperative preparation and improve maternal outcomes.