Maternal Mid-upper Arm Circumference as a Predictor of Low Birth Weight Outcome Among Newborn Deliveries of Adolescents in a Tertiary Level Hospital

Background: Maternal malnutrition is a major cause of low birth weight (LBW) newborn outcome especially among adolescent mothers. It is one of the key drivers of child stunting and initiates the vicious cycle of intergenerational malnutrition. The body mass index prior to pregnancy or at the initial trimester is currently being used to establish the desired weight gain all throughout gestation. However, Filipino adolescents often delay their first antenatal visit at a later stage of pregnancy. Without a baseline weight, the establishment of appropriate weight gain and nutritional status is often challenging. Mid-upper arm circumference (MUAC) was proven to be a good proxy measure of acute malnutrition however there is no global consensus on what MUAC cut-off point to use to identify pregnant adolescent at risk for delivering LBW babies. Finding the optimal cut-off could facilitate early identification and intervention of pregnant adolescents who are nutritionally-at-risk, and could eventually break the cycle of intergenerational malnutrition.

Methods: A cross-sectional study was conducted among adolescent ages 10 to 19 years who delivered babies in a tertiary hospital in the Philippines. The study was done for a period of six months. Maternal MUAC and LBW outcome were documented, and their association determined using a logistic regression analysis. To measure diagnostic accuracy, the sensitivity, specificity and the area under the curve were taken for each MUAC point. A receiver operating characteristic (ROC) curve was used to aid the MUAC cut-off determination.

Results: Out of 237 newborn deliveries, 35% were noted with low birth weight while 65% have normal birth weight. Majority of the mothers were on their late adolescence at 78%. The crude association for the MUAC cut-offs <23.00cm, <23.50cm and <24.00cm and LBW showed a significant value of 2.19, 2.25 and 2.39 at 95% CI respectively. However, it is only the cut-off <24.00 cm that showed significant result for adjusted association by the logistic regression analysis. The MUAC cut-off <24.00cm also showed a better trade off value between the sensitivity and specificity. Furthermore, the optimal maternal MUAC measurement that predicts LBW newborn outcome points to <24.00cm cut-off based on the ROC curve.

Conclusion: This study shows that the maternal MUAC is predictive of low-birth-weight outcome among adolescent deliveries. A MUAC cut-off of <24.00 cm was superior than lower cut-offs studied. The pregnant adolescents might need higher MUAC cut off than adults to allow timely intervention and prevention of poor neonatal outcome . By doing this simple screening test, suspected pregnant adolescent can be easily identified and referred for further confirmatory testing and intervention.