Prevalence of Iron Deficiency and Iron Deficiency Anemia during Pregnancy: A Single Centre Canadian Study

Background

Iron deficiency (ID) is the most common and widespread nutritional deficiency in both developing and developed countries (Mei et al., 2011; World Health Organization, 2001). Women of childbearing potential are at highest risk of ID due to regular menstrual losses as well as the increased iron demands of pregnancy and lactation (Lynch, 2011; McMahon, 2010). During pregnancy, the risk for ID and iron deficiency anemia (IDA) increases due to the additional iron requirements to support expansion of blood volume/red cell mass and growth of the fetus and placenta (McMahon, 2010; Mei et al., 2011). Common symptoms of ID with or without anemia during pregnancy include fatigue, shortness of breath, difficulty concentrating, higher rates of preterm delivery, and red blood cell transfusions (World Health Organization, 2001). Poor prenatal iron status is also associated with diminished cognitive performance, language ability, and motor functions in the child (Tamura et al., 2002). Despite international recommendations and guidelines on the screening and management of ID in pregnancy, it remains a problem of epidemic proportions and is often left unrecognized and untreated.

To increase recognition and appropriate management of ID and IDA in pregnancy, we developed and implemented a quality improvement project, the IRON Deficiency project in Pregnancy: Maternal Iron Optimization (IRON MOM). This project was implemented January 1^st, 2017 at St. Michael's Hospital (SMH), an inner-city tertiary centre in Toronto, Canada. The IRON MOM included educational resources for clinicians and patients, standardized oral iron prescriptions, modified lab requisitions, and clinical pathways to guide the screening, diagnosis and management of ID for obstetricians.

Objective

The primary objective of this study was to assess the prevalence of ID and IDA in unselectively screened pregnant women after the implementation of the IRON MOM quality improvement project.

Methods

We performed a retrospective audit of administrative laboratory data collected from all obstetrical clinics between January 1 and December 31, 2017. ID was defined as a serum ferritin <50μg/L (Guyatt et al., 1992) . IDA was defined as a dual diagnosis of ID and anemia based on hemoglobin levels <110 g/L and ferritin levels <50μg/L. Descriptive statistics were used to calculate frequencies and proportions. SAS version 9.4 was used to perform the analyses.

Results

A total of 1830 pregnant women were screened for ID during their obstetrical visit. Of the 1830 pregnant women, 1307 had one ferritin test and 523 pregnant women had two or more tests. A total of 91.3% (1193/1307) of pregnant women were iron deficient (ferritin <50μg/L) where 31.5% (411/1307) had ferritin levels between 15-29μg/L, and 49.4% (645/1307) had severe ID (ferritin <15μg/L). For the women who had two or more ferritin tests, 78.6% (411/ 523) were iron deficient at the first visit which then increased to 96.2% (503/523) by their second visit. When ferritin and hemoglobin values were linked and measured on the same day, 25.9% (346/1336) of pregnant women had IDA over the course of their outpatient care.

Conclusion

After the implementation of the IRON MOM, we found an extremely high prevalence of ID in our pregnant patient population in the outpatient setting. This confirms that ID remains an underappreciated problem, even at a tertiary care centre. Our findings highlight a tremendous gap in awareness, which demands strategies to improve knowledge translation. Future directions include the simplification and digitization of IRON MOM to empower pregnant women to advocate for their care.