Prenatal diagnosis and perinatal outcomes of fetuses with congenital duodenal obstruction: A nine-year retrospective study from China.

INTRODUCTION

Congenital duodenal obstruction (CDO) is one of the most common fetal gastrointestinal anomalies, but previous prenatal studies tend to investigate CDO as a portion of gastrointestinal obstruction. Few studies describe the genetic findings of CDO, especially copy number variants, in fetal cohorts with a relatively large sample size. The study aims to investigate the detection rate of genetic causes at different levels and to explore the potential influencing factors of perinatal outcomes of fetuses with CDO.

MATERIAL AND

METHODS

This retrospective study analyzed karyotype, chromosomal microarray analysis, and trio-whole exome sequencing (trio-WES) results of singleton fetuses suspected of CDO in a tertiary center between January 2014 and September 2023. In addition, perinatal outcomes and postnatal medical records of enrolled cases were followed up and analyzed.

RESULTS

A total of 98 fetuses were included in the study, of which 69 (70.4%) were classified as isolated CDO and 29 (29.6%) were classified as non-isolated. The overall rate of genetic anomalies was 20.4% (20/98). Trisomy 21 (9/98 [9.2%]) and microduplication of the 17q12 region (3/98 [3.2%]) were the most common chromosomal numerical abnormalities and pathogenic copy number variants found in this cohort, respectively. Compared to chromosomal microarray analysis, no additional pathogenic or likely pathogenic variants were found in seven cases undergoing trio-WES. The rate of chromosomal numerical and structural abnormalities was significantly higher in the non-isolated group (8/29 [27.6%] vs. 6/69 [8.7%], p < 0.05). In terms of perinatal outcomes, the live birth rate was significantly higher in the isolated group (52/69 [75.4%] vs. 15/29 [51.7%], p < 0.05) largely due to fewer terminations of pregnancy. All cases with positive genetic results elected to terminate the pregnancy, and 82% of those with negative results opted to continue the pregnancy. Neonatal mortality was significantly higher in the non-isolated group (2/15 [13.3%] vs. 0/52 [0.0%], p < 0.05). The overall neonatal survival rate was 97.0% (65/67).

CONCLUSIONS

The present study highlights the value of prenatal diagnostic testing for fetuses suspected of CDO, both in isolated and non-isolated cases. Genetic diagnostic outcomes exert substantial influence on pregnancy decision-making. Perinatal outcome and short-term prognosis of affected fetuses are reasonably favorable when known genetic causes are excluded.