Relationship of placental edge thickness and cervical length to gestational age at delivery in patients with placenta previa

Background & Objective: Placenta previa and its accompanying fetomaternal complications are increasing day by day because of globally increasing rates of cesarean deliveries, trends of assisted reproductive techniques, and delaying pregnancies to later ages. Placenta previa is an important contributor to iatrogenic and mostly emergent preterm deliveries, which add to increased neonatal morbidity and mortality. The predictors of preterm deliveries can help clinician make necessary preparations for optimal fetomaternal outcome. The aim of the current study was to determine relationship of placental edge thickness and cervical length with gestation at delivery in patients having placenta previa.

Methods: It was a descriptive case series study conducted in the department of obstetrics and gynecology, Medical Teaching Institute Lady Reading Hospital Peshawar from January 2020 till January 2021. Seventy five patients fulfilled the inclusion criteria and were included in the study. Already diagnosed cases of placenta previa, with singleton alive pregnancies and gestation of 28 weeks or more were enrolled. Trans vaginal ultrasound was done to determine placental edge thickness and cervical length. Patients data on gestation at delivery were collected from hospital records.

Results: A significant negative correlation between the placental edge thickness and gestational age at delivery was seen (r= -0.566, P= 0.001). The correlation between length of cervical canal and gestation at delivery was positive (r= 0.362, P=0.001). Also thick placental edge of > 2cm had significant association with birth before 37 weeks (P=0.023). A short cervix of less than 2.5 cm had also statistically significant association with birth before 37 weeks (P=0.022).

Conclusion: There is linear inverse relationship of placental edge thickness with gestation at delivery. The relationship of cervical length with gestation is positive linear. Patients with thick placental edge are more likely to deliver preterm than those having thin placental edge.