Abstract
Hemoglobin levels in pregnant women may decrease with advancing gestational age due to a greater increase in plasma volume than in erythrocyte mass. Studies comparing changes in hemoglobin levels between the first and third trimesters in the same respondents remain limited. This study aimed to determine the difference in hemoglobin levels between the first and third trimesters among pregnant women at Public Health Center I East Denpasar. This quantitative study used an analytical observational design with a paired comparative longitudinal approach and was conducted in March 2026. The sample consisted of 30 pregnant women selected using accidental sampling. First-trimester data were obtained from medical records, whereas third-trimester data were obtained through venous blood examination using a Micros ES-60 Hematology Analyzer. Data were analyzed descriptively, tested for normality using the Shapiro–Wilk test, and subsequently analyzed using a paired-samples t-test. The mean hemoglobin level in the first trimester was 12.85 g/dL, and all respondents were classified as having normal hemoglobin levels. In the third trimester, the mean hemoglobin level was 10.38 g/dL; 23 respondents were classified as having low hemoglobin levels, while 7 respondents had normal levels. The mean decrease in hemoglobin level was 2.47 g/dL. The data were normally distributed with a p-value of 0.053, while the paired-samples t-test showed p < 0.001. There was a significant difference in hemoglobin levels between the first and third trimesters. Regular hemoglobin monitoring is recommended to support the prevention of anemia during pregnancy.
