Anencephaly Defects Do Not Alter Macroscopic Development of the Ureterovesical Junction in Human Fetuses

To compare morphometric parameters of the bladder, bladder trigone, and intramural ureter between human fetuses with and without anencephaly, adjusting for fetal age and weight.

Thirty-seven human fetuses were analyzed (23 controls and 14 with anencephaly), ranging from 11 to 35 weeks post-conception. Bladder dimensions, trigonal measurements, and right and left intramural ureter lengths were obtained by standardized microdissection and digital morphometry. Group comparisons were performed using Student's t-test. Multivariable linear regression models adjusted for fetal age and weight were constructed using HC3 robust standard errors.

In unadjusted comparisons, total fetal length (p = 0.171) and fetal weight did not differ significantly between groups, whereas crown-rump length showed a borderline difference (p = 0.050). No significant differences were observed in trigonal or intramural ureter measurements. After adjustment, significant group differences persisted only for global body parameters. No independent effect of anencephaly was identified for bladder or UVJ measurements. Fetal age demonstrated consistent positive associations with trigonal and intramural ureter parameters in both groups. A strong bilateral linear association between right and left intramural ureter lengths was observed in both groups, with high coefficients of determination (R² = 0.893 in controls and R² = 0.868 in anencephalic fetuses; p < 0.001 for both), demonstrating marked symmetry of ureteral development Conclusions: Macroscopic morphometric development of the bladder trigone and intramural ureter is preserved in anencephalic fetuses, suggesting that severe NTDs do not impair gross structural maturation of the ureterovesical junction during fetal life.