Amniocentesis performed for karyotyping after identified ultrasonographic abnormalities: what to expect?

Objectives: The aim of this study was to evaluate the relative risk of identifying fetal chromosomal anomalies after finding ultrasonographic (US) abnormalities in a high-risk population who underwent amniocentesis.

Methods: A retrospective review of a cohort of patients with single pregnancies who underwent genetic amniocentesis was undertaken. Univariate and multivariate analysis were used to determine the best correlations between US findings and chromosomal abnormalities.

Results: Overall, 191 chromosomal abnormalities were found in 5,604 fetuses (3.4%). Multivariate analysis showed chromosomal abnormalities were significant ly associated with anomalies of the central nervous system (OR = 4.4, 95% CI 2.2-8.7), face and neck (OR = 15.7, 95% CI 9.2-26.8), heart (OR = 5.4, 95% CI 2.6-11.2), abdomen (OR = 5.6, 95% CI 2.9-10.9), extremities (OR = 5.7, 95% CI 2.4-13.4), an increased nuchal fold (OR = 5.2, 95% CI 3.3-8.1), an intrauterine growth restriction (OR = 3.6, 95% CI 1.6-7.9) and a short femur (OR = 4.1, 95% CI 1.4-12.1).

Conclusions: Our results confirm the validity of specific US markers in detecting chromosomal abnormalities in the fetus.