Morphological Spectrum of Extrachorial Placentas: A Descriptive Gross Anatomical Study

Abstract

Introduction: Placenta extrachorialis, encompassing circumvallate and circummarginate placentas, is a condition where fetal membranes insert inside the placental margin, potentially affecting pregnancy outcomes. Reported prevalence varies widely due to differences in diagnostic methods and populations. This study aimed to determine the prevalence of placenta extrachorialis and its subtypes in a contemporary cohort and compare findings with existing literature.
Methodology: This hospital-based cross-sectional study at S.V. Medical College, Tirupati, India, examined placentas from singleton pregnancies collected post-delivery via convenience sampling. Placentas were fixed in 10% formalin and macroscopically analyzed for shape, weight, chorioamniotic membrane insertion and umbilical cord characteristics. Maternal details were recorded from hospital records. Data were recorded in an approved proforma, and analyzed using SPSS for descriptive statistics.

Results: A total of 950 placentas from singleton pregnancies at S.V. Medical College, Tirupati were examined. The mean maternal age was 25.48 ± 3.4 years, and the mean maternal hemoglobin level was 11.57 ± 0.95 g/dL. The prevalence of extrachorial placentas was 5.8%. Of these, circumvallate placentas accounted for 2.7% and circummarginate placentas for 3.1%.The mean weight of extrachorial placentas was 448.7 ± 76.3g, while the mean weight of normal placentas was 445.3± 76.8 (p>0.05). No association was found between placenta extrachorialis and previous history of abortion, preterm deliveries, or low birth weight (p > 0.05).

Conclusion: Our study determined a 5.8% prevalence of placenta extrachorialis, with 2.7% circumvallate and 3.1% circummarginate placentas. These findings enhance understanding of this condition’s occurrence in our population. Further research is needed to standardize diagnostic criteria and explore clinical implications.