Introduction
Nowadays, anemia is one of the most prevalent and important nutritional disorders in the world. Common causes of anemia are iron deficiency, infectious diseases, lack of essential nutrients (e.g. folate, vitamins A, B12, B6, C, E and D), blood diseases and acute/chronic infections [1 ,2 ,3]. Iron deficiency is the most common cause of anemia which is a serious public health problem mostly affecting children and pregnant women. World Health Organization estimates that 42% of children under the age of 5 years and 40% of pregnant women have anemia [5 ،4]. Considering the importance of anemia in pregnant women and since scant studies have been conducted on it in Golestan province of Iran, this study aims to assess the prevalence of maternal anemia and its related factors in pregnant women in Golestan province.
Methods
This cross-sectional analytical study was conducted on pregnant women referred to health centers affiliated to Golestan University of Medical Sciences whose information was registered in the Nab system and had medical records. Using the Environmental Performance Index (EPI) info software, a sample size of 821 was determined. To increase the validity of the study, the sample size increased to 1000. Information extracted from the medical records of pregnant women included: Location, age, interpregnancy interval, parity, education, place for receiving medical care, number of received medical care, history of urinary tract infection (UTI) before pregnancy, age of first pregnancy, age of marriage, and blood test results based on hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration and red blood cell count. Chi-square test and multiple logistic regression analysis were used to find demographic/obstetric factors related to anemia.
Results
The results showed that the prevalence of anemia was 18.4%.; 19.27% ​​had severe anemia, 63.03% had moderate anemia, and 17.7% had mild anemia. The mean age of pregnant women was 25±12.64 years. The interpregnancy interval, parity, age of first pregnancy, age of marriage, month of pregnancy, history of UTI before pregnancy, number of received medical care and education had statistically significant relationship with anemia in pregnant women according to the results of chi-square test (P<0.05). However, the place for receiving medical care and the place of residence had no statistically significant relationship with maternal anemia (P>0.05) (Table 1).




According to the multiple logistic regression analysis results, having a history of UTI before pregnancy increased the risk of maternal anemia by 3.18 times (95% CI=2.74-6.63). Regarding the number of received medical care, the number <2 increased the risk of maternal anemia by 4.54 times (95% CI=3.91-5.33). Education was also a strong predictor of anemia, such that pregnant women with academic education were 20% less likely to had anemia than those with high school education. 
Discussion
The results of the present study showed a maternal anemia prevalence of 18.4%. The prevalence was significantly related to the interpregnancy interval, parity, age of first pregnancy, age of marriage, month of pregnancy, history of UTI before pregnancy, number of received medical care and education, but the place for receiving medical care and the place of residence had no statistically significant relationship with maternal anemia.
In a study by Vakili et al., the prevalence of anemia in Yazd province was reported 7.2%. In their study, the prevalence of anemia had no significant association with age, level of education, and occupation of the pregnant women, but varied significantly in urban areas [6]. This is against our results. The prevalence of anemia in the study by Latifi et al. in Bandar-e Turkmen was 13.4%, which is close to the rate reported in the present study. Consistent with the present study, they found that with increase in the pregnancy month, the prevalence of anemia increases due to the physiological needs, which requires the use of iron supplements [7]. There is a need for more interventional studies on maternal care and general health of pregnant women using a larger sample size at epidemiological levels and assessing the various causes of maternal anemia.

Ethical Considerations
Compliance with ethical guidelines
This study was approved by the Ethics Committee of Shahroud University of Medical Sciences (Code: IR.SHMU.REC.1398.005).

Funding
This study is the result of the research project of the first author of the article, Mostafa Majidnia, Department of Epidemiology, Faculty of Health, Shahroud University of Medical Sciences, Shahroud.

Authors' contributions
Study design: Aylar Kalteh Ei and Mostafa Majidnia; Data collection, data analysis and data interpretation: Mostafa Majidnia; Writing the initial draft: Hasan Kohi and Ahmad Nooreddini; Review and final approval: All authors.

Conflicts of interest
The authors declare no conflict of interest.

Acknowledgements
The authors would like to thank the Vice-Chancellor for Research and Technology of Golestan University of Medical Sciences and all women who participated in the study.


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