The incidence of urogenital malformations in the normal population was compared [
9]: 0.07% for solitary kidney, 0.003% for renal dysplasia, 0.25% for horseshoe fusion kidney, and 0.8% for duplication and 0.05% for ectopic kidney. In the present study, the incidence of urogenital malformation in children with congenital NTDs was significantly higher than that in normal subjects. This suggests that urogenital malformation in children with congenital NTDs remains as a clinical problem that needs to be urgently solved.
Previous researches show that NTDs were caused by genetic factors, decreased production of chorionic gonadotropin in early pregnancy or the insensitivity of embryonic receptor cells to the hormone, etc. [
12], indicating that NTDs are correlated to both genetic and environmental factors [
13]. The incidence of urogenital malformation in the present study was lower than that reported in foreign literatures. The reason may be due to regional and ethnic differences. Among all malformations, solitary kidney had the highest incidence. This is similar to the reports of foreign literatures. The differences in gender, birth place (urban or rural), birth order, age of the mother and NTD type between children with and without urogenital malformation were not statistically significant. Furthermore, the present study revealed that children with urogenital malformation are prone to skeletal muscle system malformation (
P = 0.012). Therefore, in the perspective that children with urogenital malformations are prone to skeletal muscle system malformation, urogenital malformation may be the most closely related to genetic factors. This also explains why urogenital malformations are not correlated to environmental factors in the present study. Similar to previous studies, unilateral renal agenesis will not increase the chance of disease of the contralateral kidney. However, if the patient develops a disease, the prognosis will be poorer than those with two normal kidneys [
12]. This explains the reason for the correlation between these malformations. In addition, ectopic kidney can cause hydronephrosis and lithogenesis due to the abnormal position of the kidney, and induce renal hypertension [
12,
13]. Furthermore, although renal dysplasia is often asymptomatic, hypertension can be caused by vascular malformation [
13]. in the process of embryonic development, the skeletal muscle system was also homologous with the urogenital system that originated from the mesoderm, and the development time is also in the early embryo [
14‐
18].
In the present study, among the 30 children with urogenital malformation, merely six cases were diagnosed due to the abnormal appearance in early stage, while the remaining cases had no clinical symptoms. The presence of urogenital malformation was merely found during the routine B-ultrasonic examination before the operation. Hence, there is a need for neurosurgeons and urologists to comprehensively evaluate these children, and inform their families of their condition and prognosis. As shown in previous studies, for children with bladder ectropion, bladder duplication, hypospadias and cryptorchidism, it’s suggested to give them surgical therapy during their childhood [
18]. Although these urogenital malformations did not progress and no complications occurred during the follow-up, long-term prognoses are needed through further follow-ups.