Correlation between gross morphology of the human placenta and birth weight in normotensive and pre-eclamptic pregnancies in Northwest Ethiopia

Abstract

Objectives: The objective of this study was to investigate correlation of gross morphology of human placenta with birth weight in normotensive and pre-eclamptic pregnancies obtained from Bahir Dar, Northwest Ethiopia. Methods: Institutional based comparative cross-sectional study was carried out on 200 term placentas (37 to 42 weeks of gestation) between October and January 2015. 150 placentas from normotensive and 50 from pre-eclamptic pregnancies were collected and examined for weight, diameter, thickness and number of cotyledon. Birth weight and placental-fetal weight ratio also measured. Results: The mean birth weight in pre-eclamptic pregnancies (2.6 kg) was significantly (p=0.0001) reduced as compared to birth weight (3.1 kg) in normotensive pregnancies. However, placental-fetal weight ratio had no significant (p=0.658) difference between normotensive (6.34:1) and pre-eclamptic (6.41:1) groups. Birth weight was correlated with placental weight (r=0.572), diameter (r=0.583), thickness (r=0.192) and number of cotyledons (r=0.647) in the pre-eclamptic group. Birth weight was also correlated with placental weight (r=0.572), diameter (r=0.583), and number of cotyledons (r=0.647) in the normotensive group. However, no correlation was found between placental thickness (r=0.192) and birth weight in the normotensive group. Conclusion: Birth weight was significantly reduced in pre-eclamptic pregnancies as compared to normotensive pregnancies. Morphology of placenta such as weight, diameter and number of cotyledons were correlated with birth weight in both groups, but placental thickness was only correlated with birth weight in pre-eclampsia, but not in normotensive group. Placental-fetal weight ratio had not significant difference between the groups. Examination of placental morphology prenatally using ultrasound and observation immediately after delivery is important for better management of this and subsequent pregnancies.