Sonographic assessment of placental location: A mere notional description or an important key to improve both pregnancy and perinatal obstetrical care? A large cohort study

During a standard obstetrical sonogram, the assessment of placental location (PL) is often limited to a mere notional description without formulating any association to possible implications on pregnancy and childbirth. The aim of the study was to speculate if different sites of PL may have a role in influencing fetal presentation-(FP) at birth and if certain pregnancy-complications may be more closely associated with one rather than with another PL. We conducted an observational-prospective-cohort study on pregnant women referred to the Ob/Gyn Unit of Padua University for routine third-trimester ultrasound scan. For all eligible patients we evaluated the correlation between sites of PL and perinatal maternal/fetal outcomes. Non-cephalic presentation was found in 1.4% of anterior, 8.9% of posterior, 6.2% of fundal and 7.2% of lateral insertions. FP at the beginning of the third trimester as opposed to presentation at birth was concordant in 90.3% of anterior, 63.3% of posterior and 76.5% of lateral insertions. Considering only non-cephalic fetuses we observed a decreasing probability for spontaneous rotation in the following lies: 88% anterior-PL, 80% posterior-PL, 77% lateral-PL, and 70% fundal-PL. Patients with posterior-PL (significantly associated with previous-CS) had a significantly higher CS-rate (due to previous-CS and breech-presentation). Significant differences were found in terms of gestational-hypertension and fresh-placental-weight between different sites of PL. In conclusion our data showed that an understanding of the role that PL plays in influencing the incidence of certain maternal-fetal conditions may assist Clinicians in improving perinatal maternal/fetal outcomes.