Patterns of routine cranial ultrasound findings among preterm babies at Moi Teaching and Referral Hospital

Abstract

Background: Preterm delivery and low birth weight are the number one cause of infant mortality. Incomplete development and sub-optimal physiological adjustments make them prone to vascular injuries in the brain like intraventricular haemorrhage, periventricular leukomalacia and others. Routine cranial ultrasound, done on day 3 or 4 of life, is recommended for any infant 32 weeks and below to guide management and outline prognosis. This is critical for detecting intracranial pathologies in preterm babies, which if undiagnosed, can lead to adverse neurodevelopmental outcomes. Cranial ultrasound is relatively inexpensive and uses non-ionising radiation. However, due to workload and other resource limitations, babies' access to routine cranial ultrasound is dependent on priority. Objectives: To determine the findings of routine cranial ultrasound and the association between demographic factors and abnormal cranial ultrasonographic findings amongst preterm babies at the new-born unit of Moi Teaching and Referral Hospital. Methods: A cross-sectional study was done between September 2023 and March 2024. The sample size calculated was 127. All preterm babies born at 37 weeks gestation and below were consecutively recruited and consented. Cranial ultrasound was done on day 3 or 4 by the principal investigator, their images stored, verified by the radiologist and the findings documented. An interviewer-administered questionnaire was used to collect and document information on socio-demographic data of the mother and clinical characteristics of the baby. Data entry and cleaning was done. Data was analysed using descriptive statistics, in means, median and standard deviation for numerical data and frequencies and proportions for categorical data. Bivariate analysis was done using chi square and Fisher’s exact test to test for association between demographic factors and abnormal cranial ultrasound findings. Multivariate analysis was done to evaluate the factors associated with the outcomes. Results: Out of 127 preterm babies enrolled, 54.3% (69) were female and 45.7% (58) were male. The mean gestational age was 29.5 ± 3.1 weeks. 41.7% (53) of the mothers had a parity of 2 and ≥3 was 39.4 (50). 55.1% (70) were between 28-32 weeks and 46.5% (59) weighed between 1000-1500 grams. 36.2% (46) had abnormal findings which included intracranial haemorrhage (23.6 %,), ventriculomegaly (18.9%), periventricular leukomalacia and congenital anomalies each at (3.2%). Out of the 46, 40% (12) had grade II intraventricular haemorrhage, while 20% (6) had intracerebral haemorrhage. There was significant association between low gestational age (P value = 0.002), low birth weight (P <0.001), increased mothers' parity (P=0.024) with abnormal cranial ultrasound findings. Conclusion: More than a third of the babies had abnormal cranial ultrasound findings, the commonest being intracranial haemorrhage followed by ventriculomegaly. The main type of haemorrhage was intraventricular followed by intracerebral. Low gestational age, low birth weight and increased mothers’ parity was associated with abnormal cranial ultrasound findings but not as independent predictors. Recommendations: Routine cranial ultrasound should be done for every preterm infant <32 weeks or <1500 grams.