The utility of detailed first trimester ultrasound examination in abnormal fetal nuchal translucency.

OBJECTIVE: To determine the value of a first trimester fetal ultrasound examination in cases of an increased nuchal translucency (NT).

METHOD: A detailed fetal ultrasound examination was performed within 4 days of a detection of a first trimester increased NT.

RESULTS: As many as 23 fetuses were evaluated. Severe anomalies were detected in eight and mild anomalies were detected in six fetuses. Two fetuses had trisomy 13, one had trisomy 21, and 16 fetuses had a normal karyotype. A chromosomal analysis was not available in four fetuses with major anomalies due to parental decision. In one fetus, craniosynostosis was detected only at 24 weeks' gestation.

CONCLUSIONS: The current study shows that a first trimester targeted scan of fetuses with an increased NT in an experienced center can shorten the parental decision-making process and spare parents a prolonged period of diagnostic uncertainty and anxiety, particularly when a structural anomaly is clearly diagnosed in the first trimester.