Pregnancy factors affecting birth weight of babies born at the Nairobi Hospital, Kenya.

Abstract

Birth weight is a major indicator of neonatal health. Approximately 8% and 4.2% of all babies born in Kenya are classified as low birth weight and macrosomic respectively (UNICEF, 2012; Sanghvi et al., 1989). Bunyoli (2016) found prevalence of macrosomia at KNH to be 5.4%. The primary aim of this study was to identify pregnancy factors significantly affecting birth weight of babies born at TNH. The objective of the study was to model birth weight of babies born at TNH using multinomial logistic regression. Longitudinal data from obstetric health records for all singleton live births at TNH from 1st of April 2018 to 30th of March 2019 were reviewed retrospectively. The pertinent data was collected using a structured checklist. Frequency tables, Pearson’s Chi square and multinomial logistic regression were used to investigate relationship between neonatal birth weight and pregnancy factors. The results revealed that out of 1573 singleton deliveries studied, the proportion of babies with low birth weight and macrosomia were 6.7% and 5.8% respectively. The adjusted odd ratio results for low birth weight baby versus normal weight baby were as follows; parity of 1≤ 3 (OR= 0.512; 95% CI 0.272 – 0.963,p=0.038), parity>3 (OR= 0.041; 95% CI 0.004 – 0.431,p=0.0078), obesity (OR= 0.418; 95% CI 0.220 – 0.797,p=0.008), preeclampsia (OR= 5.40; 95% CI 2.29-12.74, p=0.00012), term gestation (OR= 0.0073; 95% CI 0.0038 – 0.0143,p≤0.00001) and post term gestation (OR= 0.0016; 95% CI 0.0002 – 0.0128,p≤0.00001) were found significant. The adjusted odd ratios for macrosomic versus normal weight baby at birth; obesity (OR= 2.428; 95% CI 1.51 - 3.91,p=0.00025), diabetes in pregnancy (OR= 5.085; 95%CI 1.715 - 15.076,0.0034), sex being a boy ( OR= 1.860;95% CI 1.191 -2.905,p=0.0064), term baby ( OR=x 356; 95% CI 196 – 645,p≤0.00001) and post term baby (OR= 569;95% CI 313 – 1037,p≤0.00001) were found significant. The study concluded that maternal obesity, diabetes in pregnancy, and gestation at birth are significant pregnancy factors affecting both low birth weight and macrosomia at TNH. These findings are in agreement with many local and international studies on neonatal weight.