Background and Aim: Anemia is the most prevalent nutritional deficiency in the world, affecting almost 30% of  people worldwide, especially the pregnant women. On the other hand preterm birth is responsible for 2/3 of the infant mortality rate; therefore we performed this study to find the relationship between hemoglobin level in the first trimester of pregnancy and preterm delivery.

Material and Methods: This descriptive-analytical study was performed in the years 1392 – 1393 in Qazvin Province. 3000 pregnant women (age range:18 - 40 years), with gestational age of  less than 12 weeks were selected from 5 medical health centers. 284 participants were excluded because of IUFD, anomalies, abortion, lack of cooperation or referral to other centers for follow up or performance of lab. tests. The first trimester Hb was recorded in a questionaire for every subject and cases were observed for spontaneous preterm delivery (less than 37 weeks).Using SPSS16 software, data were analyzed by chi -square test, T- test and logestic regression.

Results: In this study the prevalence rates of anemia and preterm birth were 22.2% and 19.9% (542 cases) respectively. Mean gestational age was 38.28 ± 3.56 and the rate of preterm birth in the subjects with normal Hb level was 19.3%, and 21.9% in the patients with anemia. which revealed a significant relationship between maternal anemia and preterm birth (p <0.008). Also the relative risk for preterm delivery in anemic women was 1.117, CI: 95% (1.09 – 1.46) (P=0.046).   

Conclusion: This study demonstrated the relationship between maternal anemia in the first trimester and preterm birth. Therefore, preconception evaluation and anemia treatment in the women of childbearing age is recommended.

Key words: Preterm birth, Hemoglobin , Anemia , Pregnancy.

Received: Jan 11, 2016      Accepted: Aug 20, 2016