Service de Gynécologie obstétrique I -CHU Hassan II Fès Maroc

Case report

A 26 year-old woman (G1P0) with non-contributive history was referred to our fetal unit for detailed ultrasonography at 17 weeks of her pregnancy.

Ultrasonographic examination revealed a heart situated outside of the thoracic cavity with cerebral ventriculomegaly and oligohydramnios. No other abnormalities were detected, and the cardiac outflow tracts appeared normal. The findings were strongly suggestive of ectopia cordis.

The parents were informed of the poor prognosis. Genetic amniocentesis was refused and the parents did not opted for termination of the pregnancy.

Fetal demise occurred at 22 weeks of pregnancy. The mother aborted a 150 g. female fetus without complications. Postnatal examination confirmed the heart of the fetus lying outside the thoracic cavity. Unilateral clubfoot was also noticed.

Image 1 and video 1: Sagittal view of the fetus showing the heart beating outside the thorax.

Images 2, 3: Axial view of the head with different filters showing bilateral moderate ventriculomegaly.

Image 4: Postnatal images of the fetus with ectopia cordis and unilateral clubfoot.

Discussion: The case shows sonographic diagnosis of ectopia cordis in a fetus at 17 weeks of gestation.

Definition: Ectopia cordis (EC) is defined as an anomaly in which the fetal heart lies outside the thoracic cavity. It is a rare congenital abnormality with an incidence of 5.5–7.9 per 1 million of live births^[1]. Ectopia cordis may occur as an isolated finding or may be associated with other ventral body wall defects affecting the thorax, abdomen or both.

Etiology: The cause of ectopia cordis is currently unknown, and most cases are sporadic^[1,2]. Cervical, cervicothoracic, thoracic, and thoracoabdominal types of ectopia cordis have been described^[3]. The cervical and thoracic ectopia cordis are relatively rare, while the abdominal and thoracoabdominal types are more common.

Pathogenesis: Failure of fusion of paired cartilage bars of the embryonic sternum leads to sternal cleft. This may occur as an isolated malformation, or it may be associated with larger category of ventral body wall defects that affect the thorax, abdomen, or both ^[4]. Congenital heart defects associated with ectopia cordis may represent deformations secondary to the mechanical distortion of the developing heart following early rupture of the chorion and/or yolk sac.

Diagnosis and sonographic findings: The prenatal diagnosis of ectopia cordis is easily made by ultrasound, allowing visualization of the heart outside the thoracic cavity.

Differential diagnosis: Differential diagnoses include limb–body wall complex, amniotic band syndrome, and pentalogy of Cantrell^[5]. Prenatal diagnosis of ectopia cordis was reported by Bick et al^[6] and Tongsong et al^[7] at weeks 11 and 9 of gestation, respectively.

Associated anomalies: The genetic cause of ectopia cordis is unknown. A possible relation between this congenital heart disease and chromosome aberration is described in the literature ^[4]. Reported karyotype abnormalities include trisomy 18, Turner syndrome and 46,XX,17q+ ^[8,9].

Prognosis: The prognosis is generally poor and depends on the severity of the intracardiac malformations and the presence of associated abnormalities.

Management: Obstetric management should include careful search for associated anomalies, especially cardiac anomalies, and assessment of fetal karyotype. Pregnancy termination prior to viability or non-aggressive management in the third trimester should be considered and discussed with the parents.

References

[1] Repondek-Liberska M, Janiak K, Wloch A. Fetal echocardiography in ectopia cordis. Pediatr Cardiol 2000;21: 249–52.

[2] Leca F, Thibert M, Khoury W, Fermont L, Laborde F, Dumez Y. Extrathoracic heart (ectopia cordis). Report of two cases and review of the literature. Int J Cardiol 1989; 22:221–8.

[3] van Hoorn JH, Moonen RM, Huysentruyt CJ, van Heurn LW, Offermans JP, Mulder AL. Pentalogy of Cantrell: two patients and a review to determine prognostic factors for optimal approach. Eur J Pediatr 2008;167:29e35.

[4] Engum SA. Embryology, sternal clefts, ectopia cordis, and Cantrell’s pentalogy. Semin Pediatr Surg 2008;17:154e60.

[5]  Carvalho JS. Fetal heart scanning in the first trimester.Prenat Diagn 2004;24:1060–7.

[6]  Bick D, Markowitz RI, Horwich A. Trisomy 18 associated with ectopia cordis and occipital meningocele. Am J MedGenet 1988;30:805–10.

[7] Tongsong T, Wanapirak C, Sirivatanapa P, Wongtrangan S. Prenatal sonographic diagnosis of ectopia cordis. J Clin Ultrasound 1999;27:440–5.

[8] Shaw SW, Cheng PJ, Chueh HY, Chang SD, Soong YK. Ectopia cordis in a fetus with trisomy 18. J Clin Ultrasound 2006;34:95–8.

[9] Grethel EJ, Hornberger LK, Farmer DL. Prenatal and postnatal management of a pat with pentalogy of Cantrell and left ventricular aneurysm. A case report and literature review. Fetal Diagn Ther 2007;22:269–73.