Maternal risk factors associated with low birth weight at Kenyatta national hospital.

Abstract

The World Health Organization defines Low birth weight as weight at birth of less than 2,500 grams, irrespective of gestational age. Low birth weight is a major public health problem in low-resource settings, as it increases the risk of infant morbidity, mortality and disability. Low birth weight is responsible for significant costs to families, communities and health systems. The morbidity and mortality associated with LBW can be reduced if maternal risk factors are detected early and interventions put in place. Objectives: To determine the maternal risk factors associated with low birth weight at Kenyatta National Hospital. Design: This was a hospital based unmatched case control study. Setting: Kenyatta National Hospital, Nairobi, Kenya. Methods: Cases were mothers who delivered low birth weight babies. The subsequent mother who delivered a normal weight baby was recruited as a control. Study participants were recruited from 10th March to 1st May 2014 when the sample size was achieved. A structured, interviewer administered questionnaire was used to collect data from the mothers. Data analysis was conducted in SPSS (version 17) using a data analysis plan developed prior to data collection and based on the study objectives. The analysis was conducted in three stages including use of both descriptive (univariate) statistics and inferential (bivariate and multivariable) statistical approaches. Results: Out of a total of 1874 deliveries, 186 births were low birth weight, giving a prevalence of 9.9 %.The risk of LBW births was lower among women who were self employed (AOR = 0.32, 95% CI 0.15-0.70) and those that attended at least 4 ANC visits (AOR = 0.11, 95% CI 0.04-0.17). The risk of LBW was higher among women with unplanned pregnancy (AOR = 2.30, 95% CI 1.13-4.70), those reporting pica (AOR = 3.10, 95% CI 1.43-6.75) and those with history of preceding pregnancy adverse outcome (AOR = 3.75, 95% CI 1.61-8.76). The highest risk of LBW was among women who were HIV positive ( AOR= 5.57, 95%CI 1.39-22.38) and those with Hypertensive disease (AOR 17.78 95% CI 5.54-57.04). Most of the LBW delivery can be attributed to Unplanned pregnancy and Hypertensive disease. Conclusion : The prevalence of low birth weight at KNH was 9.9%. Pica use, preceding pregnancy adverse outcome, unplanned pregnancies, HIV and hypertensive disease were identified as significant risk factors for low birth weight. Most of the LBW deliveries were attributed to unplanned pregnancy and hypertensive disease in pregnancy.