Determinants of Maternal Mid-Upper Arm Circumference among Pregnant Adolescents Aged 10–19 Years in Mukuru Informal Settlement

Adolescent pregnancy remains a major public health concern, with implications for both maternal and child health. Nutritional status during pregnancy, often measured using Mid-Upper Arm Circumference (MUAC), is a critical determinant of maternal and neonatal outcomes. The objective was to examine socio-demographic and dietary factors associated with maternal MUAC among pregnant adolescents in Mukuru informal settlement, Nairobi. A cross-sectional analytical study was conducted among 250 pregnant adolescents aged 10–19 years attending five health facilities in Mukuru. Data were collected using structured questionnaires, key informant interviews, and focus group discussions. Quantitative data were analyzed using descriptive statistics, chi-square tests, and logistic regression to determine associations between socio-demographic factors and MUAC. Qualitative data were analyzed thematically. Overall 75.7% of participants had normal nutritional status (MUAC >23 cm). Marital status, minimum meal frequency, and smaller household size were positively associated with normal nutritional status, while low dietary diversity and lower education levels reduced the odds of achieving adequate nutrition. The study highlights the importance of promoting dietary diversity and supporting educational attainment among pregnant adolescents to improve maternal nutrition. Targeted interventions in informal settlements are needed to address these vulnerabilities and strengthen maternal and child health outcomes.