International values for haemoglobin distributions in healthy pregnant women

Eric O Ohuma; Melissa F Young; Reynaldo Martorell; Leila Cheikh Ismail; Juan Pablo Peña-Rosas; Manorama Purwar; Maria Nieves Garcia-Casal; Michael G Gravett; Mercedes de Onis; QingQing Wu; Maria Carvalho; Yasmin A Jaffer; Ann Lambert; Enrico Bertino; Aris T Papageorghiou; Fernando C Barros; Zulfiqar A Bhutta; Stephen H Kennedy; Jose Villar

doi:10.1016/j.eclinm.2020.100660

International values for haemoglobin distributions in healthy pregnant women

EClinicalMedicine. 2020 Dec 2:29-30:100660. doi: 10.1016/j.eclinm.2020.100660. eCollection 2020 Dec.

Authors

Eric O Ohuma¹, Melissa F Young², Reynaldo Martorell², Leila Cheikh Ismail^{3

4}, Juan Pablo Peña-Rosas⁵, Manorama Purwar⁶, Maria Nieves Garcia-Casal⁵, Michael G Gravett⁷, Mercedes de Onis⁵, QingQing Wu⁸, Maria Carvalho⁹, Yasmin A Jaffer¹⁰, Ann Lambert^{4

11}, Enrico Bertino¹², Aris T Papageorghiou^{4

11}, Fernando C Barros¹³, Zulfiqar A Bhutta¹⁴, Stephen H Kennedy^{4

11}, Jose Villar^{4

11}

Affiliations

¹ Maternal, Adolescent, Reproductive and Child Health (MARCH) Centre, London School of Hygiene and Tropical Medicine (LSHTM), London, UK.
² Hubert Department of Global Health, Emory University, Atlanta, Georgia.
³ Clinical Nutrition and Dietetics Department, University of Sharjah, Sharjah, United Arab Emirates.
⁴ Nuffield Department of Women's and Reproductive Health, University of Oxford, Oxford, UK.
⁵ Department of Nutrition and Food Safety, World Health Organization, Geneva, Switzerland.
⁶ Nagpur INTERGROWTH-21st Research Centre, Ketkar Hospital, Nagpur, India.
⁷ Departments of Obstetrics and Gynecology and of Global Health, University of Washington, Seattle, WA, USA.
⁸ Department of Ultrasound, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China.
⁹ Department of Obstetrics and Gynaecology, Faculty of Health Sciences, Aga Khan University Hospital, Nairobi, Kenya.
¹⁰ Department of Family and Community Health, Ministry of Health, Muscat, Oman.
¹¹ Oxford Maternal and Perinatal Health Institute, Green Templeton College, University of Oxford, Oxford, UK.
¹² Unit of the University, AOU City of Health and Science of Turin, Turin, Italy.
¹³ Programa de Pós-Graduação em Saúde e Comportamento, Universidade Católica de Pelotas, Pelotas, Brazil.
¹⁴ Center for Global Child Health, Hospital for Sick Children, Toronto, Canada.

Abstract

Background: Anaemia in pregnancy is a global health problem with associated morbidity and mortality.

Methods: A secondary analysis of prospective, population-based study from 2009 to 2016 to generate maternal haemoglobin normative centiles in uncomplicated pregnancies in women receiving optimal antenatal care. Pregnant women were enrolled <14 weeks' gestation in the Fetal Growth Longitudinal Study (FGLS) of the INTERGROWTH-21^st Project which involved eight geographically diverse urban areas in Brazil, China, India, Italy, Kenya, Oman, United Kingdom and United States. At each 5 ± 1 weekly visit until delivery, information was collected about the pregnancy, as well as the results of blood tests taken as part of routine antenatal care that complemented the study's requirements, including haemoglobin values.

Findings: A total of 3502 (81%) of 4321 women who delivered a live, singleton newborn with no visible congenital anomalies, contributed at least one haemoglobin value. Median haemoglobin concentrations ranged from 114.6 to 121.4 g/L, 94 to 103 g/L at the 3^rd centile, and from 135 to 141 g/L at the 97^th centile. The lowest values were seen between 31 and 32 weeks' gestation, representing a mean drop of 6.8 g/L compared to 14 weeks' gestation. The percentage variation in maternal haemoglobin within-site was 47% of the total variance compared to 13% between sites.

Interpretation: We have generated International, gestational age-specific, smoothed centiles for maternal haemoglobin concentration compatible with better pregnancy outcomes, as well as adequate neonatal and early childhood morbidity, growth and development up to 2 years of age.

Funding: Bill & Melinda Gates Foundation Grant number 49038.

Keywords: Anaemia; Healthy pregnant women; INTERGROWTH-21st; International Haemoglobin values.

Grants and funding

001/WHO_/World Health Organization/International