Sonographic nuchal markers for Down syndrome are more common but less ominous in gestations with a male fetus

Autor: Mark I. Evans, R. Zamir, Amir Weissman, R. Avrahami, Arie Drugan
Rok vydání: 2002
Předmět:
Zdroj: Fetal diagnosis and therapy. 17(5)
ISSN: 1015-3837
Popis: Objective: A change in the normal male-to-female ratio has been reported in some autosomal trisomies (i.e., trisomy 21 or trisomy 18). The objective of the present study was to evaluate the male-to-female ratio in pregnancies with sonographic nuchal markers for Down syndrome. Methods: The results of amniocenteses performed for isolated nuchal markers for Down syndrome were grouped by fetal sex and by maternal age. The male-to-female ratio in normal and trisomic gestations was compared. Results: 584 fetal karyotypes were available for analysis. A significantly higher male-to-female ratio was observed. More affected gestations were observed in association with a female fetus. These differences were mainly attributed to the group of patients younger than 35 years that represents more than 80% of our study population. No difference was observed in pregnancies of patients older than 35 years of age. Conclusions: In patients younger than 35 years, sonographic nuchal markers for Down syndrome are more frequent (but apparently less ominous) in gestations with a male fetus. If the gender is known, counseling can be modified to include such differential risks.
Databáze: OpenAIRE