Objective Cantrell syndrome, a rare congenital disorder, is characterized by a unique collection of defects on the midline abdominal wall, the lower sternum, the anterior diaphragm, and the diaphragmatic pericardium in addition to some form of intracardiac defect. So far, most of the reports on fetuses with Cantrell syndrome worldwide are either case reports or literature reviews, and few comprehensive studies on fetuses with Cantrell syndrome have been reported, especially in domestic literature. This study aims to provide a detailed analysis of 15 cases of Cantrell syndrome fetuses, focusing on their prenatal ultrasound manifestations and postnatal examination outcomes.

Methods  A retrospective analysis was conducted with 15 cases of fetuses diagnosed with Cantrell syndrome via prenatal ultrasound examinations between March 2018 and July 2023. Ultrasound examinations were performed in accordance with the Guidelines for Obstetric Ultrasound in China, including first-trimester fetal ultrasound scan and routine second-trimester fetal ultrasound scan. Gestational age was evaluated and nuchal translucency (NT) was measured during first-trimester fetal ultrasound scan at 11 to 13+6 weeks. The diagnostic criterion for NT thickening was NT≥3.0 mm and the screening of severe fetal structural malformations was performed, including the screening of the head, the neck, the thorax, the abdominal content, the abdominal wall, the limbs and other structures. During routine second-trimester fetal ultrasound scan, the fetal biometry was assessed and an anatomy survey was performed. Post-induction and postnatal outcomes of fetuses diagnosed with Cantrell syndrome by prenatal ultrasound were followed up by postnatal observation, inquiries with the electronic medical record system, or telephone follow-up. The prenatal ultrasound imaging manifestations and features of the fetuses with Cantrell syndrome, as well as their post-induction or postnatal examination results were comprehensively summarized and analyzed.

Results  The study involved pregnant women of the average age of 30.1±3.5 years, with ultrasound diagnoses made between 11 to 26 weeks of gestation (mean: 13.4±4.0 weeks). Among the 15 cases, there were 10 singleton pregnancies and 5 cases of one twin in a pair of twins. These twins comprised 3 monochorionic diamniotic twins and 2 dichorionic diamniotic twins, with Cantrell syndrome present in one of the twins in all 5 cases. Thirteen cases were diagnosed by fetal ultrasound scan conducted in the first trimester, with 10 being singleton pregnancies and 3 being twin pregnancies (1 monochorionic diamniotic twins and 2 dichorionic diamniotic twins). One case was missed in the first-trimester ultrasound scan, resulting in a missed diagnosis rate of 7.1%. Two cases were diagnosed in second-trimester fetal ultrasound scan, both involving monochorionic diamniotic twins. One case was a referral from another hospital at 19 weeks, while the other was initially not diagnosed for Cantrell syndrome and was diagnosed at 26 weeks. Prenatal ultrasound examinations revealed a consistent pattern of abnormalities across all 15 fetuses, including manifestations of ectopic cordis combined with abdominal protrusion mass. Specifically, 4 cases were diagnosed with omphalocele, 4 with gastroschisis, and the remaining 7 had uncertain coverage of the membrane on the surface of the abdominal protrusion mass. Six fetuses had complete ectopic cordis, while nine had partial ectopic cordis. Fetal echocardiography was performed in 5 cases, revealing intracardiac malformations in 4 cases (80%). Notably, 2 cases were diagnosed in the second trimester, including one with right ventricular hypoplasia accompanied by interventricular septal defect and another with double outlet right ventricle accompanied by interventricular septal defect. Additionally, 2 cases were diagnosed in the first trimester, one with single atrium and single ventricle, and the other with complete transposition of the great arteries. Of the 15 cases of fetuses with Cantrell syndrome, 13 (86.7%) exhibited concomitant malformations in other systems. These included 7 cases of spinal malformations, 4 limb abnormalities, 3 umbilical cord abnormalities, 2 central nervous system malformations, 1 facial malformation, and 2 fetal hydrops. Spinal malformations were the most prevalent concomitant malformation, accounting for 46.7% of all cases. Among the 14 fetuses undergoing NT examination, 7 (50%) had increased NT, and 5 of them had cystic hygroma. All 10 singleton pregnancies underwent induced abortion, and the appearance of the induced fetuses was consistent with the prenatal ultrasound manifestations. In the twin pregnancies, 2 cases experienced intrauterine fetal death, while 2 underwent selective reduction. Notably, 3 of these cases exhibited postnatal appearances consistent with prenatal ultrasound manifestation, while 1 case showed an indistinct appearance after selective reduction during delivery. One case was lost to follow-up. Genetic testing was conducted for 4 induced fetuses, none of which yielded any relevant pathogenic or potentially pathogenic variants.

Conclusion  In conclusion, Cantrell syndrome manifests prenatally with ectopic cordis combined with abdominal protrusion mass, often accompanied by intracardiac malformations and other concomitant malformations. While most cases can be diagnosed in the first trimester, there remains the possibility of missed diagnoses, which underscores the importance of close follow-up in the second trimester.