Low Birth Weight: Case Definition & Guidelines for Data Collection, Analysis, and Presentation of Maternal Immunisation Safety Data Authors: Clare L. Cutland1-3, Eve Lackritz4, Azucena Bardají Alonso5, Trésor Bodjick6, Ravichandran Chandrasekaran7, Chandrakant Lahariya8, Brian Magowan9, Tamala MallettMoore10, Ali Mtoro11, Jeff Murray12, Imran Nisar13, Milagritos Tapia14, Jayani Pathirana1-3, Sonali Kochhar15, Flor M. Muñoz16 The Brighton Collaboration Low birth weight Working Group#. 1

Medical Research Council: Respiratory and Meningeal Pathogens Research Unit,

Johannesburg; 2

Department of Science and Technology National Research Foundation, Vaccine

Preventable Diseases 3

Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa

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EL

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ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic – University of Barcelona, Barcelona, Spain 6 TB 7

Professor of Pediatrics, Madras Medical College

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CL

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BM

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Sanofi Pasteur Inc., Swiftwater, PA, USA

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AM

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JM

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IN

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University of Maryland, CVD?

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Global Healthcare Consulting, India

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Departments of Pediatrics, Molecular Virology and Microbiology, Baylor College of

Medicine, Houston, Texas, USA

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*Corresponding author: Clare Cutland Tel: number. Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Johannesburg. E-mail: [email protected] #

Brighton Collaboration homepage: http://www.brightoncollaboration.org

Disclaimer: The findings, opinions and assertions contained in this consensus document are those of the individual scientific professional members of the working group. They do not necessarily represent the official positions of each participant’s organisation (e.g., government, university, or corporation). Specifically, the findings and conclusions in this paper are those of the authors and do not necessarily represent the views of their respective institutions.

Keywords: Low birth weight, adverse event, immunisation, guidelines, case definition

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1. PREAMBLE 1.1.

Need for Developing Case Definitions and Guidelines for Data

Collection, Analysis, and Presentation for Low birth weight as an Adverse Event Following Maternal Immunisation

The birth weight of an infant is the first weight recorded after birth, ideally measured within the first hours after birth, before significant postnatal weight loss has occurred. Low birth weight (LBW) is accepted as a birth weight of less than 2500 grams (up to and including 2499 grams), as per the World Health Organization (WHO) definition1. This definition of LBW has been in existence for many decades. In 1976, the 29th World Health Assembly agreed on the currently used definition. Prior to this, the definition of LBW was ‘2500 grams or less’. Low birth weight is further categorized into Very low birth weight (VLBW, 2500 grams6, 7 . Additionally, low birth weight is associated with long-term disability, impaired language development8, impaired academic achievement, and increased risk of chronic diseases including stroke and diabetes.

Low birth weight rates in a community are a valuable indicator of maternal health, maternal nutrition and poverty. In malaria endemic areas, malaria in pregnancy is a major risk factor for infant mortality through its contribution to low birth weight and prematurity, the main effects associated to malaria during gestation. The reduced birth weight is thought to be effected through placental insufficiency, which leads to intra-uterine growth retardation and 3

premature delivery. In addition, the evaluation of costs associated with low birth weight in low-income settings shows that reducing the burden of low birth weight would translate into important cost savings both to the health system and to the households9.

What leads to low birth weight? Causes of low birth weight are multi-factorial, but are related to either preterm birth (shortened gestation,