Objectives: To evaluate the characteristics of presentation and metabolic risk factors in relation to the extent of involvement in infants with nephrolithiasis. Methods: A total of 111 infants (age range 0.3–11.8 months, 58.6% were girls) diagnosed with nephrolithiasis in the first year of life were included in this retrospective study. Data on age at diagnosis, gender, family history of nephrolithiasis, parental consanguinity, symptoms on admission, urinary abnormalities, surgery, size of renal calculi, and metabolic risk factors (hypercalciuria, hyperuricosuria, hyperoxaluria, hypocitraturia, cystinuria, hypercalcemia) were recorded for each patient and compared with the number of kidneys affected (bilateral vs. unilateral), the number of kidney stones (multiple vs. single), and the kidney stone size (microlithiasis vs. larger stones). Results: Overall, 58.6% of the infants were girls. Irritability was the most common symptom on admission (34.2%). Microlithiasis (62.2%), bilateral kidney involvement (61.3%), multiple kidney stones (73.9%), and metabolic risk factors (45.0%, hypercalciuria in 31.5%) were commonly noted. Bilateral nephrolithiasis was associated with significantly higher rates of hypercalciuria than unilateral nephrolithiasis (39.7% vs. 18.6%, respectively; p=0.022). The presence of multiple kidney stones was associated with a significantly higher rate of hyperuricosuria than the presence of a single kidney stone (20.7% vs. 0.0%, respectively; p=0.006). Larger kidney stone size was associated with a significantly higher rate of hyperoxaluria than microlithiasis (100.0% vs. 0.0%; respectively; p=0.002). Conclusion: In conclusion, our findings revealed the association of nephrolithiasis in the first year of life with identifiable metabolic abnormalities in a considerable portion of patients. Our findings emphasize the association of identifiable metabolic abnormalities with the extent of nephrolithiasis and a higher likelihood of bilateral kidney involvement, multiple kidney stones, and larger kidney stones in cases of hypercalciuria, hyperuricosuria,
Corresponding Author: