Screening for Anemia During Pregnancy: What Evidence Suggests
The following is part of a series of project updates from the Department of Community Medicine at Rajarata University of Sri Lanka. MHTF is supporting their project, Measuring Economic Impact of Maternal Morbidity. More information on MHTF supported projects can be found here.
Written by: Dr. Suneth Agampodi, Department of Community Medicine, Rajarata University
Anemia during pregnancy is long been identified as one of the most common maternal morbidities. It is estimated that more than 80% of pregnant women in Sub Saharan Africa and South Asia are having anemia during pregnancy.
Due to high prevalence and known complications of anemia during pregnancy, screening for anemia in booking visit is universally done in all most all countries. In some developed countries a second hemoglobin assessment is recommended around 24-28 weeks, whereas in resource poor settings, this second screening is often not practiced. Instead, clinical examination (conjunctival method) is used as the screening procedure during the pregnant period, after the first hemoglobin test.
Based on extensive evidence on cause of anemia during pregnancy and various interventions, oral iron supplementation is been practiced as one of the major strategy to prevent anemia during pregnancy. It is also accompanied with folic and vitamin B supplementation and worm treatment.
Physiological changes in pregnancy suggest that the risk of developing anemia is highest at around 30 weeks of gestation due to haemodilution effect. This knowledge has not been properly transferred to maternal care practices. In our study on maternal morbidity estimates in Sri Lanka it was observed that the prevalence of anemia during first trimester was around 6-7% compared to 15- 16% in second and third trimester. These pregnant women were identified during a screening programme. All these women having anemia were on routine iron-folate and Vit B supplementation and had received anti-helminthes treatment. They were routinely been examined by a medical practitioner (once in 4 weeks during first 28 weeks and every fortnight after 28 weeks). Only less than 10 % of the screen detected mothers were previously diagnosed as having anemia. During the screening, a clinical examination was carried out and complete history was taken to detect clinical anemia. However, 80% of anemic mothers were not showing clinical symptoms and signs of anemia.
The present observation raises an important question regarding the current practices related to anemia screening during pregnancy in Sri Lanka, which is applicable to other developing countries as well. One aspect is the validity of the present recommendation of anemia screening at booking visit. Early diagnosis is always preferable for prevention of early complications. However, if resources are limited and more than one screening could not be performed, what would be the best time to screen? At booking visit or later in pregnancy? If resources are available, a second screening would be ideal. We suggest that evidence synthesis is required at this stage to re-evaluate present screening practice.