Are you up to date on MUAC cutoffs for pregnant women? Undernutrition measures in pregnancy?

Maternal undernutrition has been linked to poor pregnancy outcomes such as poor fetal development, preterm births, small for gestational age, and low birth weight. In turn, these outcomes lead to increased infant morbidity and mortality. In low-resource settings, mid-upper arm circumference (MUAC) has been widely accepted as a measure of fat-free mass, and changes in MUAC tape measure can be a useful indicator of protein-energy malnutrition or starvation. To assess acute malnutrition, a MUAC cutoff of <11.5 cm is generally accepted for children 6 months to 5 years of age, but no standard cutoff has been established for adults. In response, Tufts University, the Food and Nutrition Technical Assistance III Project, and USAID collaborated on a systematic review of the association between MUAC tape measure and adverse health outcomes in pregnant women and found that the majority of studies reviewed used a cutoff between 22-24 cm.

There are, however, certain caveats to this range of numbers. First, there were a wide range of cutoffs used, from 21-29 cm. While studies support a significant association, the WHO has not yet set standardized number to serve as the cutoff. On one hand, this is reasonable considering the wide variety of settings and variables that exist. Characteristics of each of the study sites varied widely, and there were notable gaps in the data collected from each location. It was difficult to pin down a specific number for the cutoff, or even a reasonable range, because of tradeoffs that existed. In the higher range of MUAC cutoffs, many more women may be falsely identified as “at risk”, resulting in a larger burden for the healthcare system in terms of resources needed to further test and treat. In the lower range of MUAC cutoffs, fewer women who may actually be at risk will be correctly identified.

In conclusion, the study suggests that an universal cutoff may not be feasible and that each country conduct its own cost-benefit analysis to determine the best set of numbers that works for their citizens, taking into account their own unique considerations. While imperfect, MUAC tape measure is still an important tool that can give policymakers insight into the state of maternal nutrition and its effects on newborns and babies.

Blog by Vivian Shih