A longitudinal study of anemia status and its association with postpartum hemorrhage among pregnant women in Chengdu,China

OBJECTIVE: To investigate the anemia status and its changing trend among pregnant women in Chengdu, China, and to explore the association between anemia and postpartum hemorrhage. METHODS: A total of 548 healthy singleton primiparas were selected and followed up from three hospitals in Chengdu until delivery. Data on maternal demographic characteristics, delivery information were collected with questionnaire, and the hemoglobin( Hb) concentration was determined using cyanide methemoglobin method in each trimesters. Mixed fitting logistic regression models were performed to test the association between anemia and postpartum hemorrhage. RESULTS: The overall prevalenceof anemia was 31. 9%. The prevalence of anemia in the 1st, 2nd and 3rd trimesters during pregnancy was 5. 5%, 22. 8% and 18. 2%, respectively. The prevalence of anemia of pregnant women in the 2nd and 3rd trimesters were significantly higher than 1st trimester( P < 0. 05). Most of them were mild anemia, and pregnant women with severe anemia had not been found. After adjustment confounding factors( age and type of delivery etc. ), pregnant women with anemia in the 3rd trimester showed a 6. 47 times higher risk of postpartum hemorrhage( 95% CI 1. 23-34. 23). CONCLUSION: The anemia status of pregnant women in the 2nd and 3rd trimesters should be paid attention and improvement. Anemia of pregnant women in 3rd trimester is negative associated with postpartum hemorrhage.