Determining the Placental-Birth Weight Ratio at Term at the Benue State University Teaching Hospital, Makurdi, North-Central Nigeria: A Cross-Sectional Study

Background: The birth weight of a neonate depends mainly on optimal placental growth and function in utero. Measurement of the placental weight, the neonatal birth weight and the placenta-birth weight ratio is an indirect way of assessing this vital relationship. This underscores the significance of placental weight as a major determinant of neonatal weight.

Objective: To determine the placental weight, birth weight and placental- birth weight ratio in a cross-section of subjects attending our antenatal clinic

Methodology: This was a clinic-based cross-sectional study from July 31, 2015 to June 30, 2017. Four hundred and forty-four (444) subjects attending our antenatal clinic were recruited through systematic random sampling. The placental weights and birth weights were measured within one hour of delivery using a table –top beam weighing scale. Statistical analysis was performed with SPSS version 20.0 and significance set at a P-value of <0.05.

Results: Four hundred and forty-four subjects (whose mean age was 28.75 years, mean parity was 1.5 and mean gestational age at delivery was 38.70 weeks) participated in the study. The mean placental weight was 670 g, the mean birth weight was 3300 g and the mean placental-birth weight ratio (PBWR) was 20.3. Two hundred and eighteen (49.1%) of the neonates were male and 226(50.9%) were female. There was a positive correlation between the placental weight and the placental-birth weight ratio(X2 = 108.570; p-value = 0.001). There was a progressive decline in the PBWR with gestational age at term.

Conclusion: The placental weight increased with the birth weight and the gestational age. The placenta-birth weight ratio declined progressively with gestational age.