To evaluate the utility of a routine screening for abnormal invasive placentation (AIP) in women with previous Caesarean sections (CS) according to the placental insertion site. Retrospective analysis of AIP and maternal outcomes of women evaluated between January 2014 and 2016 with a scoring system based on 5 sonographic criteria (i.e. placental lacunae, loss of the hypoechoic retro-placental space, bladder wall abnormalities, abnormal vascularisation at myometrial-bladder interface and placental thinning) which identified 2 risk classes (high: ≥2 criteria, low: ≤1 criteria). AIP was determined following surgery and/or pathological analysis. We enrolled 135 women, 97 women (71.9%) with history of ≥2 CS without placenta previa (PP) (CS group) and 38 women (28.1%) with PP (9/38 with a previous CS and 29/38 with no CS) (PP group). According to our score, 122 women (90.4%) were at low risk, 13 (9.6%) at high risk. AIP was confirmed in 14/135 (10.4%) cases. Hysterectomy was performed in 9 cases with confirmed AIP. All AIP cases were in the PP group (14/14, 100%). Women with PP had higher risk of AIP than those with multiple CS without PP (37.8% vs 0%, p<0.0001). Our score diagnosed 10/14 confirmed AIP with 71% of sensitivity (IC95%:48;94) and 98% of specificity (IC95%:96;100), PPV of 77% (IC95%:54;100) and NPV of 97%(IC95%:94;100). Placental lacunae alone had a sensitivity and a specificity of 86% and 93%. Logistic and multiple regression analyses, corrected for maternal age and BMI, gestational age and fetal weight at time of delivery, need of radiology assistance, suggested that only placental lacunae were significantly associated with AIP (CR 28.05; 95% CI 2.91 to 270.58; p < 0.01) and blood loss during CS (CR 0.553; r = 0.588; p < 0.001). Our data suggest that AIP prevalence is not increased in women with multiple previous CS without PP; only women with PP need a routine screening for AIP. Placenta lacunae are the most associated criterion for AIP and blood loss during CS.