Clinicopathological features and prognosis of fetal prune belly syndrome: analysis of five cases / 中华围产医学杂志

ABSTRACT

Objective:To investigate the clinicopathological features and prognosis of fetal prune belly syndrome (PBS).Methods:This retrospective study collected and analyzed the clinical data of five fetuses with PBS diagnosed through a pathological autopsy in Women and Children's Hospital, School of Medicine, Xiamen University, from December 2016 to January 2023. The clinicopathological features of these cases were summarized, and the subsequent pregnancy outcomes in their mothers were followed up. A descriptive statistical method was used for data analysis.Results:(1) Megabladder or enlarged bladder was observed in the five fetuses (four males and one female) with a maximum diameter of 4.4 cm (1.6-8.9 cm). Two fetuses were complicated by renal dysplasia, one by an absence of kidney, and ureters, one by bilateral ureterectasia and possible posterior urethral atresia, and one by the dilated cerebral ventricle, gastroschisis, exposed viscera, and scoliosis. The pregnancies were terminated at the gestational age of 15 +6 weeks (12 +5-19 +4 weeks). (2) The five fetuses exhibited distended and thin abdominal walls with excessive dilation of the bladder. There were two cases with the partially absent abdominal wall, one with diaphragmatic dysplasia, two with renal dysplasia complicated by pyeloureterectasis, two with urethratresia and anal atresia, one with hydroderma and sever seroperitoneum, and one with absent left kidney and left ureter. The muscle layers of the bladder wall, abdominal wall, and ureter tube wall were of varying thickness, and the arrangement of muscle fibers was disordered with incomplete or absent muscle layers in some areas. Moreover, the glomeruli and renal tubules were reduced to varying degrees and fibrous interstitial hyperplasia was observed. Immunohistochemical staining revealed thin muscle layers and broken muscle layers in some regions. (3) One fetus carried a compound heterozygous variant of c.907G>A/c.461C>T in the DHCR7 gene, which was found to be a pathogenic variation. The other four cases had no obvious abnormalities. (4) By August 2023, apart from one case lost to follow-up, the other four were followed up for 68 months (7-80 months). Three women were successfully conceived again after an interval of 16, 24, and 19 months, respectively, and the other one did not conceive due to being in a recovery period. Three neonates were delivered at term in good condition, and no obvious abnormality in growth or development was reported during a three-year follow-up. Conclusions:Fetal PBS is a rare congenital malformation characterized by dysplasia of the abdominal wall and the bladder smooth muscle layers. The subsequent pregnancy is generally not affected.