670 - Maternal mid-upper arm circumference (MUAC) during pregnancy and risk of adverse neonatal outcomes: a systematic review and meta-analysis

Publication Number: 3648.670

Nandita Perumal, University of South Carolina, Columbia, SC, United States; Berthe Abi Zeid, University of South Carolina, Columbia, SC, United States; Junyi Frenzel, Wayland High School, Wayland, MA, United States; Kalkidan OS. Yibeltal, University of South Carolina, Columbia, SC, United States; Carrie G. Wade, Harvard Medical School, Boston, MA, United States; Anne CC Lee, Warren Alpert Medical School of Brown University, Providence, RI, United States

Background: Maternal undernutrition is a major contributor to adverse birth outcomes. Mid-upper arm circumference (MUAC) is a simple, inexpensive anthropometric measure widely used in low- and middle-income countries (LMICs) to assess maternal nutritional status during pregnancy. However, the optimal MUAC threshold for predicting risk of adverse neonatal outcomes remains uncertain.

Objective: To synthesize the evidence on the association between maternal MUAC during pregnancy and adverse neonatal outcomes.

Design/Methods: We systematically searched Cochrane Central Register of Controlled Trials, Embase, Pubmed, Web of Science, Global Health, Global Index Medicus, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) from inception to August 2025. Longitudinal studies with pregnant women, of any age, residing in LMICs, with a measure of maternal MUAC in pregnancy and at least one neonatal outcome (birthweight, low birthweight, gestational age, preterm birth, small-for-gestational age [SGA], stillbirth, or neonatal mortality) were included. DerSimonian-Laird random-effects meta-analysis was conducted to estimate the pooled relationship between low MUAC and adverse neonatal outcomes. The review was registered on Prospero (CRD420251119566).

Results: Of 2339 titles and abstracts, 977 were screened and 49 studies included (Figure 1). Studies were from 21 countries from sub-Saharan Africa (n=7), Southeast and South Asia (n=7), Latin America (n=2), and Middle East (n=2), with the highest representation from Ethiopia (9/49 studies, 18%) and Indonesia (6/49 studies, 12% %). Maternal MUAC measurement ranged from single to multiple measures during pregnancy and different cut-offs were used, ranging from < 20 cm to < 27.5 cm, to define undernutrition. MUAC < 23 cm was most used across studies (19/49; 39%). Low birthweight was the most evaluated adverse birth outcome in relation to maternal MUAC across studies (26/49 studies; 53%), followed by SGA (9/49; 18%) and preterm birth (6/49; 12%). In pooled analysis, a MUAC < 23 cm was consistently associated with higher odds of low birthweight (1.90, 95% CI: 1.65, 1.28; n=9 studies, 7920 participants), preterm birth (1.86, 95%CI: 1.45, 2.38; n=3 studies, 3798 participants), and SGA (1.50, 95%CI: 1.14, 1.97; n=3 studies, 3798 participants).

Conclusion(s): There was substantial heterogeneity in the MUAC cut-offs, neonatal outcomes, and measures of association used across studies. Individual participant data meta-analysis research is needed to systematically evaluate maternal MUAC cut-offs for identifying and targeting at-risk pregnancies to prevent adverse neonatal outcomes.

Figure 1: Flowchart of included studies


Figure 2: Pooled random-effects meta-analysis of the association between maternal mid-upper arm circumference <23 cm during pregnancy and odds of a newborn with low birthweight.