Journal Article

Anthropometric measurements can identify small for gestational age newborns: a cohort study in rural Tanzania

Theander, Thor Grundtvig, Bygbjerg, Ib Christian, Nielsen, Birgitte Bruun, Ekmann, Josephine Roth, Minja, Daniel Thomas Remias, Schmiegelow, Christentze, Paulsen, Cecilie Bøge, Msemo, Omari Abdul, Møller, Sofie Lykke, Lusingu, John Peter Andrea

2019

Overview

Background Small-for-gestational-age (SGA) is associated with increased neonatal mortality and morbidity. In low and middle income countries an accurate gestational age is often not known, making the identification of SGA newborns difficult. Measuring foot length, chest circumference and mid upper arm circumference (MUAC) of the newborn have previously been shown to be reasonable methods for detecting low birth weight (< 2500 g) and prematurity (gestational age <  37 weeks). The aim of this study was to investigate if the three anthropometric measurements could also correctly identify SGA newborns. Methods In the current study from a rural area of northeastern Tanzania, 376 live newborns had foot length, chest circumference, and MUAC measured within 24 h of birth. Gestational age was estimated by transabdominal ultrasound in early pregnancy and SGA was diagnosed using a sex-specific weight reference chart previously developed in the study area. Receiver operating characteristic curves were generated for each of the anthropometric measurements and the area under the curve (AUC) compared. Operational cutoffs for foot length, chest circumference, and MUAC were defined while balancing as high as possible sensitivity and specificity for identifying SGA. Positive and negative predictive values (PPV and NPV) were then calculated. Results Of the 376 newborns, 68 (18.4%) were SGA. The AUC for detecting SGA was 0.78 for foot length, 0.88 for chest circumference, and 0.85 for MUAC. Operational cut-offs to detect SGA newborns were defined as ≤7.7 cm for foot length, ≤31.6 cm for chest circumference and ≤ 10.1 cm for MUAC. Foot length had 74% sensitivity, 69% specificity, PPV of 0.35 and NPV of 0.92 for identifying SGA. Chest circumference had 79% sensitivity, 81% specificity, PPV of 0.49 and NPV of 0.95 for identifying SGA. Finally, MUAC had 76% sensitivity, 77% specificity, PPV of 0.43 and NPV of 0.94 for identifying SGA. Conclusion In a setting with limited availability of an accurate gestational age, all three methods had a high NPV and could be used to rule out the newborn as being SGA. Overall, chest circumference was the best method to identify SGA newborns, whereas foot length and MUAC had lower detection ability. Trial registration Clinicaltrials.gov ( NCT02191683 ). Registered 2 July 2014.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Adult / Africa / Age / Anemia / Anthropometry / Anthropometry - methods / Birth weight / Births / Blood pressure / Body measurements / Chest circumference / Cohort analysis / Data collection / Evaluation / Female / Follow-Up Studies / Foot length / Gestational Age / Global and public health and healthcare / Hemoglobin / Humans / Infant / Infant mortality / Infant Mortality - trends / Infant, Newborn / Infant, Premature, Diseases - diagnosis / Infant, Premature, Diseases - epidemiology / Infant, Small for Gestational Age / Internal Medicine / Low income groups / Malaria / Male / Medical examination / Medicine / Medicine & Public Health / Mid upper arm circumference / Morbidity / Mortality / Newborn babies / Newborn infants / Pediatrics / Physiological aspects / Pregnancy / Prenatal care / Prevalence / Public health / Research Article / Retrospective Studies / Rural Population / Small for gestational age / Survival Rate - trends / Tanzania - epidemiology / Ultrasonic imaging / Urine / Womens health