[Genetic disease and diagnostic strategies in stillbirth]

Stillbirth occurs in about 1 in 1000 pregnancies. The causes are maternal, fetal, and placental; but in half of the cases, no cause can be determined. Genetic disease, a common cause of stillbirth, is diagnosed in 25-35% of patients with birth defects.

Describe birth defects found in stillbirth cases at the Instituto Nacional de Perinatología in a period of 3 years, analyze risk factors in each pregnancy, and propose an adequate approach to effectively reach the proper diagnosis of defined genetic entities related to stillbirth.

All stillbirths cases presenting birth defects and assessed by the Department of Genetics from January 2008 to December 2010 were included in this study.

We evaluated 55 stillbirths with birth defects. 31% of them showed multiple defects; 14.5%, single defects; 20%, single gene disorders; 14.5%, chromosomal abnormalities; 9%, disruptive processes; 7%, non-immune fetal hydrops, and 4% twin pregnancy. The karyotype was obtained in all cases from amniocentesis, and in half of them from umbilical cords as well. In 95% of the cases prenatal findings were confirmed through prenatal USG, and necropsy was performed in 74.5% of them.

Ultrasound, karyotype, autopsy and assessment by a medical geneticist allowed an accurate diagnosis in 81% of cases. Genetic counseling helps reduce parental anxiety and stillbirth from unknown causes.