Resumen

LOPEZ-URIARTE, Arelí  y  AGUINAGA-RIOS, Mónica. Discordance in birth defects in multiple gestations at the Instituto Nacional de Perinatología. Perinatol. Reprod. Hum. [online]. 2012, vol.26, n.1, pp.08-16. ISSN 2524-1710.

Introduction: Twin pregnancies represent less than 3% of newborns and up to 12% of perinatal deaths, with a high frequency of complications such as: characteristic of twin pregnancy, isolated birth defects and chromosomal abnormalities. Materials and methods: We reviewed the clinical records of newborns from multiple pregnancies evaluated by the Genetics Department at INPer between January 2009 and September 2011. We included 76 cases, 56 were twin pregnancies and 20 triplets. Results: There were 619 infants of multiple pregnancies, 76 were assessed by a geneticist, corresponding to 12.2% of multiple pregnancies with congenital defects, which were: a) In twins: three deformations, seven disruptions, nine birth defects, 10 defects characteristic of multiple gestation (two acardic fetuses), four syndromes (Holt-Oram and oculo auriculo vertebral spectrum and two Down syndrome), three minor defects and 20 healthy neonates. b) In triplets: one deformation, one malformation, three syndromes (Walker-Warburg, Goldenhar and Down), three defects of twins (thoracopagus), three minor defects and nine healthy neonates. Conclusions: Birth defects found in this study are similar to those reported in the world literature. We observed discordance in the presence and severity of congenital defects in all the twins studied, this observation was higher in monochorionic pairs. Several processes in the division of a fertilized egg may predispose to the development of a congenital abnormality, or it can result as an alteration in the placenta.

Palabras llave : Birth defects; twins; discordant.