New diagnostic thresholds for anemia in pregnancy

DoCM Policy Brief

We urge revision of present recommended threshold for anamia during the second trimester to be in par with new evidence based global recommendations. 

Key messages·      
1. The global comparisons of prevalence of anaemia in pregnancy shows Sri Lanka as one of the worst performing country in the middle income country category.
2. All global guidelines published by WHO, USA, UK, Australia etc. use a Hb 10.5g/dL as the threshold for anaemia in the second trimester of pregnancy. 
3. Sri Lanka is still using 11 g/dL as the cut off leading to a gross overestimation (>75%) of prevalence of anaemia in pregnancy.   
Policy options
Revise the definition of anaemia in pregnancy with the cut off level of  Hb -10.5 g/dl during the second trimester, and keep the Hb 11g/dL threshold for first and third trimester. 

Background

Prevalence of anaemia in pregnancy in Sri Lanka is reported as 29.1% with eight districts reporting more than one third pregnant women as anaemic[1]. The Global Health Observatory Data Repository[2] data has placed Sri Lanka as a country with poor performance in maternal anaemia and this is one of the worst indicator of maternal care in Sri Lanka.

In Sri Lanka, three out of ten pregnant women are classified as having anaemia and receive interventions including iron double dose.

National Guidelines for Maternal Care, published in 2015[3] recommends haemoglobin assessment at the booking visit and around 28 weeks of period of gestation (POG).  At both instances, those who are having haemoglobin levels below 11 g/dL are identified as anaemic in accordance with the previous World Health Organization (WHO) recommendations.

However, the 2012 WHO guidelines on anaemia was supersede by the e-Library Evidence for Nutrition Action (eLENA)[4] and the other WHO guidelines published in 2016[5]. Currently, trimester specific cut off points for anaemia are recommended by the WHO. In the first and third trimesters, the Hb threshold for diagnosing anaemia is 11 g/dL; in the second trimester, the threshold is 10.5 g/dL. Similar recommendations are practiced elsewhere in the world including USA[6], UK[7] and Australia[8]

Level of over-estimation

To determine the level of overestimation of anaemia, DoCM team has analyzed the haemoglobim levels of pregnant women in their second trimester, recruited to the Rajarata Pregnancy Cohort (RaPCo)[9]; the largest community base pregnancy cohort study done in Sri Lanka. The original cohort included more than 80% of the target population; pregnant women residing in Anuradhapura district and registered with the maternal care system from July to September 2019.

Outdated classification over-estimates anaemia in Sri Lanka by 79%.

Full blood count was performed for 1366 pregnant women with POG between 22 to 32 weeks, in a quality-controlled laboratory using a three-part hematological analyzer. With the globally accepted threshold of 10.5 g/dL, 373 (27.3%) women were classified as anaemic, However, 676 (49.5%) pregnant women were classified as anaemic based on current national recommendation (haemoglobin 11.0 g/dl as threshold), a 78.7% inflation in comparison to use of standard threshold values. Of those 676 pregnant women classified as anaemic, 77.5% (n=524) had not had anaemia in the first trimester confirming more “physiological” drop in haemglobin concentration. 

Implications and Recommendations

This classification leads to unnecessary investigations and a psychological disturbances to pregnant women. In addition, the performance of the national maternal care programme is also downgraded in global data comparisons where the classification is done using different thresholds. 

Threshold for diagnosis of anaemia in the second trimester in pregnancy should be lowered to 10.5 g/dL.


This work is part of RaPCo and lead by Dr. Gayani Amarasinghe, Prof.Thilini Agampodi, Dr.Wasana Mendis and Prof.Suneth Agampodi

 


[1] Family Health Bureau. Annual Report 2018. Ministry of Health, Sri Lanka, Colombo, 2020

[2] Available at https://apps.who.int/gho/data/view.main.ANAEMIAWOMENPWv?lang=en

[3] Family Health Bureau. National Guidelines for Maternal Care Volume III. Ministry of Health, Sri Lanka, Colombo, 2015

[4] WHO. Intermittent iron and folic acid supplementation in non-anaemic pregnant women. Available at http://158.232.12.119/elena/titles/full_recommendations/ifa_supplementation/en/

[5] World Health Organization. WHO recommendations on antenatal care for a positive pregnancy experience. World Health Organization, 2016.

[6] Anemia in Pregnancy, Obstetrics & Gynecology: July 2008 – Volume 112 – Issue 1 – p 201-207

doi: 10.1097/AOG.0b013e3181809c0d 

[7] Pavord, Sue, et al. “UK guidelines on the management of iron deficiency in pregnancy.” Br J Haematol (2019).

[8] Pregnancy Care Guideline, Anaemia. Australian Governemnt, Department of Health. Available at https://www.health.gov.au/resources/pregnancy-care-guidelines/part-f-routine-maternal-health-tests/anaemia

[9] Agampodi, T.C., Wickramasinghe, N.D., Prasanna, R.I.R. et al. The Rajarata Pregnancy Cohort (RaPCo): study protocol. BMC Pregnancy Childbirth 20, 374 (2020).

Leave a Reply

%d bloggers like this: