Anemia in women and children - PAHO/WHO | Pan American Health Organization

ENLACE CHILD MALNUTRITION GLOBAL CHILD MALNUTRITION ANEMIA BREASTFEEDING MONITORING BFHI TECHNICAL NOTES ABOUT

Anemia, defined as low levels of hemoglobin in the blood, seriously affects health and it is associated with poor cognitive and motor development in children and work capacity in adults, which influences the economic development of countries.

Among pregnant women, iron deficiency anemia is also associated with adverse reproductive outcomes such as preterm delivery, low-birth-weight infants, and decreased iron stores for the baby, which may lead to impaired development. Failure to reduce anemia in the Region of the Americas may result in thousands of women experiencing impaired health and quality of life, and may impair children’s development and learning.

This visualization presents estimates of the prevalence of anemia in women of reproductive age by pregnancy status and in children aged 6-59 months. The prevalence of anemia is an indicator of both poor nutrition and poor health.

SUMMARY OF MAIN FINDINGS

Anemia in women of reproductive age

Global nutrition target: 50% reduction of anemia in women of reproductive age.

Regionwide in 2019, the prevalence of anemia in women of reproductive age (women aged 15-49 years) was 15.4% (95% uncertainty interval (UI) 12.1–19.5), equivalent to 39 million women with anemia.
The prevalence of anemia in women of reproductive age decreased by 19.8% from 19.2% (95% UI:16.1–22.5) in 2000 to 15.4% (95% UI:12.1–19.5) in 2019.
The prevalence of anemia in women of reproductive age has been stagnant from 2012 (15.4% [95% UI:13.0–18.0]) to 2019 (15.4 [95% UI:12.1–19.5]), which put on the Region at a high risk of achieving the set target.
Nationally, most of the countries of the Region had decreasing trends, however, they need major efforts to achieve the target.
The prevalence of anemia in women of reproductive age varies across countries from 47.7% (95% UI: 38.0–57.5) in Haiti to 7.4% (95% UI: 5.2 – 10.6) in Guatemala.
Regionwide in 2019, prevalence of anemia was higher in pregnant women (18.9% [95% UI: 14.1–24.8]) than in non-pregnant women (15.3% [95% UI 11.8–19.5).
From 2000 to 2019, the regional prevalence of anemia in women of reproductive age has decreased by 19.8% (from 19.2% in 2000 to 15.4% in 2019), while the prevalence of anemia in pregnant women has decreased by 19.6% (from 23.5% in 2000 to 18.9% in 2019).

Anemia in children aged 6 to 59 months

In 2019, regional median anemia prevalence in children aged 6-59 months was 16.5% (95% UI:13.4–20.1), equivalent to 12 million children with anemia.
Across countries of the Americas, the prevalence of anemia in children aged 6-59 months was highest in Haiti, 60.1% (95% UI: 47.1–70.67), and lowest in the United States of America, 6.1% (95% UI: 5.1–8.4).
Since 2000, a significant reduction in the prevalence of anemia in children under five has been observed in many of the low- and lower-middle-income countries of the Region of the Americas, while in some upper-middle-income countries it has been stagnant, and increased in Canada in recent years.

Suggested citation

Anemia in women of reproductive age, and children under-five years in the Region of the Americas. ENLACE data portal. Department of Noncommunicable Diseases and Mental Health, Pan American Health Organization, 2022.

DATA CLASSIFICATION

In the map and horizontal bar chart, the data are presented in five classes created using the quantile classification method. Each class contains 20% of countries, which is easy to interpret. The quintile intervals are labeled sequentially from Quintile 1, also called the bottom quintile which includes the lowest fifth (0 to 20%) of data points to Quintile 5 (or top quintile), which includes the top fifth (80% to 100%) of data points.

DEFINITIONS

Anemia refers to low levels of hemoglobin in the blood, which seriously affects health.

Anemia in women: women aged 15−49 years with a hemoglobin concentration lower than 120 g/L for non-pregnant women and lactating women, and lower than 110 g/L for pregnant women, adjusted for altitude and smoking.

Anemia in children: children aged 6−59 months with a hemoglobin concentration less than 110 g/L, adjusted for altitude.

DATA SOURCES AND METHODS

This topic and visualization used data from the 2021 edition of the WHO global anemia estimates (see the references section).

The methodology for the 2021 edition of the WHO global anemia estimates is detailed in the technical document "WHO methods and data sources for mean hemoglobin and anemia estimates in women of reproductive age and pre-school age children 2000-2019", available online as a pdf file.

In brief, data on the prevalence of anemia and/or mean hemoglobin in women of reproductive age, collected between 1995 and 2019 were obtained from 408 population-representative data sources from 124 countries worldwide. A Bayesian hierarchical mixture model was used to estimate hemoglobin distributions and systematically address missing data, non-linear time trends, and representativeness of data sources. Full details on data sources are available on the WHO Global Health Observatory: Anemia in women and children page.

Full details on statistical methods may be found here: Finucane MM, Paciorek CJ, Stevens GA EM. Semiparametric Bayesian density estimation with disparate data sources: a meta-analysis of global childhood undernutrition. J Am Stat Assoc. 2015;110(511):889–901.

Summary of current WHO recommendations for the prevention, control and treatment of anaemia in women

Intermittent iron and folic acid supplementation is advised in menstruating women living in settings where the prevalence of anaemia is 20% or higher.
Daily oral iron and folic acid supplementation is recommended as part of antenatal care, to reduce the risk of low birth weight, maternal anaemia and iron deficiency. In addition to iron and folic acid, supplements may be formulated to include other vitamins and minerals, according to the United Nations Multiple Micronutrient Preparation (UNIMAP), to overcome other possible maternal micronutrient deficiencies.
In areas where the prevalence of anaemia among pregnant women is lower than 20%, intermittent iron and folic acid supplementation in non-anaemic, pregnant women is advised, to prevent anaemia and improve pregnancy outcomes.
In the postpartum period, iron supplementation, either alone or in combination with folic acid, for at least 3 months, may reduce the risk of anaemia by improving the iron status of the mother.
Fortification of wheat and maize flours and rice with iron, folic acid and other micronutrients is advised in settings where these foods are major staples.
In malaria-endemic areas, the provision of iron and folic acid supplements should be made in conjunction with public health measures to prevent, diagnose and treat malaria.
In emergencies, pregnant and lactating women should be given the United Nations Children’s Fund (UNICEF)/WHO micronutrient supplement providing one RNI (recommended nutrient intake) of micronutrients daily (including 27 mg iron), whether or not they receive fortified rations. Iron and folic acid supplements, when already provided, should be continued.
All pregnant women with active tuberculosis should receive multiple micronutrient supplements that contain iron and folic acid and other vitamins and minerals, according to the UNIMAP, to complement their maternal micronutrient needs.
Exclusive breastfeeding of infants up to 6 months of age should be protected, promoted and supported. The beneficiaries include the infant and the mother (i.e. longer amenorrhoea, increased birth spacing), as well as the neonate (breast milk is an important source of iron, which is very well absorbed).
A diet containing adequate amounts of bioavailable iron should underpin all efforts for the prevention and control of anaemia.

WHO methods and data sources for mean hemoglobin and anemia estimates in women of reproductive age and pre-school age children 2000-2019. Department of Nutrition and Food Safety, World Health Organization Geneva, Switzerland, March 2021. [Full text, PDF file]
Finucane MM, Paciorek CJ, Stevens GA EM. Semiparametric Bayesian density estimation with disparate data sources: a meta-analysis of global childhood undernutrition. J Am Stat Assoc. 2015;110(511):889–901.

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