Ventricular Morphometric Parameters in Preterm Neonates Assessed by Transcranial Ultrasound: A Prospective Cohort Study in a Nigerian Population

Abstract

Background: Ventricular morphometry provides objective information about the size and configuration of the cerebral ventricular system and is an important component of cranial ultrasound assessment in preterm neonates. Premature infants are particularly vulnerable to ventricular enlargement because of intraventricular haemorrhage, post-haemorrhagic ventricular dilatation, impaired white-matter development, and altered cerebral growth. The ventricular index (VI), anterior horn width (AHW), and thalamo-occipital distance (TOD) are established sonographic measurements was obtained through the anterior fontanelle. However, population-specific data describing these measurements among Nigerian preterm neonates remain limited. Objective: To characterise ventricular morphometric parameters measured by transcranial ultrasound among preterm neonates in a Nigerian population and to examine their distribution in relation to selected neonatal characteristics and ultrasound-detected brain pathology. Methods: A prospective cohort study was conducted among 105 preterm neonates admitted to the neonatal intensive care units of Meridian Hospitals, Rivers State, and Lily Hospitals, Delta State, Nigeria, between November 2025 and May 2026. Eligible neonates were born before 37 completed weeks of gestation, had birth weights of ≤2,500 g, and underwent transcranial ultrasound examination. Participants were recruited consecutively. Standard neonatal cranial ultrasound examinations were performed through the anterior fontanelle. Ventricular morphometry was assessed using AHW, TOD, and right and left VI measurements. Measurements were recorded in millimetres and interpreted using the reference criteria specified in the study protocol. Descriptive statistics were used to characterise ventricular measurements, while independent-samples t tests and one-way analysis of variance were used for selected group comparisons. Statistical significance was set at p < .05. Results:The 105 neonates had a mean gestational age of 32.12 ± 1.93 weeks and mean birth weight of 1,706.67 ± 447.92 g. The mean AHW was 3.62 ± 1.16 mm, with measurements ranging from 1.7 to 6.3 mm. The mean TOD was 25.14 ± 14.26 mm, ranging from 1.8 to 56.0 mm. The mean right VI was 13.07 ± 2.14 mm and the mean left VI was 13.39 ± 2.41 mm. The right and left VI measurements demonstrated close group-level symmetry. Based on the study's predefined interpretations, 63 neonates (60.0%) had an abnormal VI, whereas 42 (40.0%) had a normal VI. AHW was abnormal in 50 (47.6%) neonates and normal in 55 (52.4%). Lower birth weight was significantly associated with structural brain pathology, with mean birth weight of 1,490.16 ± 353.41 g among neonates with ultrasound-detected brain injury compared with 2,006.82 ± 390.23 g among those without injury (t(103) = 7.08, p < .001). Birth weight also differed significantly across specific categories of brain pathology, F(4,100) = 14.60, p < .001. Conclusion: Ventricular morphometric abnormalities were common among preterm neonates in this Nigerian cohort. The VI demonstrated the highest proportion of abnormal interpretations, followed by AHW. The near-symmetrical right and left VI measurements suggest no major group-level lateral asymmetry, whereas the wide distribution of TOD indicates substantial inter-individual variation in posterior ventricular morphology. These findings support the incorporation of standardised quantitative ventricular measurements into routine transcranial ultrasound assessment of preterm neonates in Nigeria and highlight the need for locally relevant reference data.