This study’s objective was to estimate and identify the determinants of hemoglobin concentration before pregnancy, during pregnancy, and after labor and delivery. 

A prospective cohort study design was implemented. A simple random sampling technique was used to select the participants. An interview technique was used to collect the data. Blood samples were collected before pregnancy, during each trimester, during labor and delivery, after the third stage of work, and at the 6-week postpartum period. Generalized estimating equations were used to identify the determinants of hemoglobin concentration during each phase of pregnancy. 

The mean hemoglobin concentrations of primigravida and multigravida before pregnancy were 12.41 g/dl and 10.78 g/dl, respectively. The hemoglobin concentrations of pregnant women were reduced by hookworm 0.24 g/dl, multiple pregnancy 0.16 g/dl, episiotomy 0.05 g/dl, gravidity 0.15 g/dl, age 0.03 g/dl, and gestational age 0.1 g/dl. The hemoglobin concentration increased by iron supplementation 1.02 g/dl and birth weight 0.14 g/dl. 

The study concluded that pregnancy significantly decreases the hemoglobin concentration of pregnant women reaching the lowest point during labor and delivery. Regular anemia screening intervention should be implemented after delivery.