A retrospective comparison of phototherapy need in O-B versus O-A incompatibility in a single Saudi institution.

BACKGROUND: ABO incompatibility is a major risk factor for neonatal indirect hyperbilirubinemia (NIH), requiring treatment. It has been shown that there are racial differences in direct antiglobulin test (DAT) positivity and phototherapy need in the O--B versus (vs) O--A incompatibility. The comparison between the O--B and O--A incompatibility is not well studied in Saudi Arabia. AIMS: We aimed to compare DAT positivity and phototherapy need in O-B vs O-A incompatibility in Saudi Arabia. METHODS: This retrospective cohort study was conducted in one Saudi hospital. We included a convenience sample of neonates born between 01 January 2013 and 31 December 2021. We included healthy neonates admitted to the nursery care unit only, born at≥38 weeks gestation, and had normal G6PD levels. Neonates that had no G6PD level measurement or lost follow-up post-discharge were excluded. The data span was the first 14 days of life. RESULTS: A total of 611 neonates met our inclusion criteria. Positive DAT was more prevalent in the O-B than the O-A incompatibility [43.5% vs 29.2%, p < 0.001). A greater odd of phototherapy need was observed in the O--B vs O-A incompatibility across various strata. Readmission for NIH, use of 360° exposure phototherapy, or intravenous immunoglobulin administration was more prevalent in the O-B than the O-A incompatibility (13.2% vs 5.0%, p < 0.001). A logistic regression analysis revealed that the O-B incompatibility modified the association between DAT positivity and phototherapy need. CONCLUSIONS: The O-B incompatibility had a mediator effect on the relationship between DAT positivity and the need for phototherapy in the study population, which emphasizes that the O-B and O-A are not the same from the NIH point of view.

Natural radionuclides in clay deposits: concentration and dose assessment.

Clays are among the most important industrially used minerals. Three potential clay mineral mining sites in Saudi Arabia were chosen, and 21 clay deposit samples were collected. The activity concentrations (average±standard deviation) of the naturally occurring radioactive materials (NORMs), (238)U, (226)Ra, (232)Th, (228)Ra and (40)K, were 49±20, 47±23, 34±11, 40±20 and 751 Bq kg(-1), respectively. The radiation dose assessments (e.g., absorbed dose rate, nGy h(-1); effective dose equivalent, µSv y(-1); and effective dose rate due to dust inhalation, µSv y(-1)) and hazardous indices (e.g., radium equivalent [Ra-eq] value, external hazardous index [Hex], internal hazardous index [Hin] and representative gamma level [Iγ]) were calculated. The wide variations in the activity concentrations of the NORMs according to sampling region could be due to the origin of the geological formation and the geochemical behaviour of the NORMs. Based on calculated hazardous (external and internal) indices, there were no expected radiological hazardous impacts of using clay deposits as building materials.