Risk factors and adverse perinatal outcomes associated with low birth weight in Northern Tanzania: a registry-based retrospective cohort study

Modesta Mitao, Rune Nathaniel Philemon, Joseph Obure, Blandina Theophil Mmbaga, Sia Emmanuel Msuya, Michael J. Mahande
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To determine the risk factors for low birth weight and adverse perinatal outcomes associated with low birth weight in Northern Tanzania.


A retrospective cohort study was designed using maternally linked data from Kilimanjaro Christian Medical Centre (KCMC) medical birth registry. A total of 37 799 singleton births delivered from 2000 to 2013 were analyzed. Multiple births, stillbirth and infants with birth defects were excluded. Data analysis was performed using SPSS version 16.0. Chi-square was used to compare difference in proportions between groups. The relative risks (RR) with 95% confidence interval (CIs) for the factors and adverse perinatal outcomes associated with LBW were estimated in a multivariate logistic regression models.


The incidence of low birth weight was 10.6%. Multivariate logistic regression showed that pre-eclampsia (RR 3.9; 95% CI 3.6–4.2), eclampsia (RR 5.4; 95% CI 4.1–6.9), chronic hypertension (RR 2.8; 95% CI 2.1–3.8), maternal anemia (RR 1.7; 95% CI 1.4–2.2), HIV status (RR 0.8; 95% CI 0.7–0.8), smoking during pregnancy (RR 1.9; 95% CI 1.0–3.5), caesarean section delivery (RR 1.4; 95% CI 1.3–1.5), placental abruption (RR 3.7; 95%CI 1.3–4.7), placenta previa (RR 6.6; 95% CI 4.8–9.3), PROM (RR 2.5; 95% CI 1.9–3.3), maternal underweight (RR 1.3; 95% CI 1.2–1.6), and obesity (RR 1.2; 95% CI 1.1–1.4) and female gender of baby were significantly associated with delivery of low birth weight infants. On the other hand, LBW infants had increased risk of neonatal jaundice (RR 2.7; 95% CI 1.2–6.1), being delivered preterm (RR 2.0; 95% CI 1.8–2.3), Apgar score (<7) at fifth minute (RR 5.5; 95% CI 4.5–6.6) and early neonatal death (RR 3.5; 95% CI 2.6–4.6).


Low birth weight is associated with adverse perinatal outcomes. Early identification of risk factors for low birth weight through prenatal surveillance of high risk pregnant women may help to prevent these adverse perinatal outcomes.