Predictors of abnormal Thompson score in term neonates in a tertiary hospital in Zimbabwe

BackgroundNeonatal encephalopathy, abnormal neurological function in a baby born at term is a key cause of neonatal death. In the absence of adequate training and brain imaging or monitoring in low-resource settings, clinical risk scores, such as Thompson score, have been useful to predict risk of neonatal encephalopathy. A clearer understanding of the clinical and maternal predictors of abnormal values of Thompson score would be beneficial to identify term neonates with suspected neonatal encephalopathy. MethodsA scoping review of the literature identified a set of a priori neonatal and maternal variables associated with neonatal encephalopathy in low-resource settings. Next, a prospective study of all neonates born at term admitted to Sally Mugabe Central Hospital in Zimbabwe between October 2020 and December 2022 (n=6,054) was conducted. A predictive statistical model for abnormal (>10) Thompson score (range 0-22) was developed. ResultsIn total 45 articles were identified from three databases and 10 articles were selected. 45 candidate predictors were identified -36 from the available literature and 9 from clinical data and experience. 4.06% (n=246) of neonates had an abnormal Thompson score of 10 or more on admission and 90.65% (n=223) of these neonates had an Apgar score less than 7 at 5 mins (p<0.001). 24 possible predictors were selected as the most important of which nine factors were identified as the most useful in predicting which neonates are at risk of abnormal Thompson score. These predictors and their adjusted odds ratios are: low Apgar score at 5min (OR= 0.46, 95%CI=(0.42, 0.51)), low neonatal heart rate at admission (OR=0.977, 95%CI=(0.97, 0.985)), temperature lower than 36.5{degrees}C (OR=1.64, 95%CI=(1.18, 2.28)), abnormal head shape (OR=2.12, 95%CI=(1.51, 2.97)), resuscitation received (OR=3.95, 95%CI=(1.69, 11.01)), neonatal encephalopathy as an admission reason (OR= 2.47, 95%CI=(1.37, 4.32)), risk factors of sepsis other than premature rupture of membrane and offensive liquor (OR=2.04, 95%CI=(1.1, 3.67)), respiratory distress as an admission reason (OR=2.48, 95%CI=(1.59, 3.96)), and other admission reasons (OR=1.81, 95% CI=(1.12, 2.97)). The main admission reasons in Other category include low birthweight, meconium aspiration and hypoxic ischaemic encephalopathy and congenital abnormality. ConclusionIn resource-poor settings where it may be not possible to clinically assess all admitted neonates, those with the identified risk factors should be prioritised for a Thompson score assessment. Local clinical guidelines should incorporate these factors into the clinical management of at-risk neonates and assess their impact on clinical care and neonatal outcomes.