Significance of the size of fetal anterolateral neck cysts in early gestation

Purpose: To recognize the association between the size of fetal anterolateral neck cysts and nuchal translucency, chromosomal aberration and fetal malformations.

Material and methods: We examined a consecutive collective of 51 fetuses with lateral neck cysts that presented between the 11 and 17 weeks of gestation in the years 2009 to 2016 in our department. The volume of the nuchal cysts was measured. We examined thereafter the statistical association between the cyst volumes, increased nuchal translucency, chromosomal aberrations and fetal anomalies.

Results: 46 fetuses had bilateral nuchal cysts, while 5 had a unilateral. 26 fetuses had a chromosomal aberration, 9 fetuses had structural malformations without genetic anomaly and 16 fetuses had a normal outcome. All cases with a normal nuchal translucency had a normal outcome (n = 11). 5 fetuses with an increased nuchal translucency in early gestation had a normal outcome. All fetuses with a chromosomal abnormality or structural malformations had an increased nuchal translucency (n = 35). The cyst volume significantly correlated with the outcome (normal cases 13.6 mm³, abnormal cases 136 mm³; p < 0.001), the nuchal translucency (105.5 mm³; p < 0.001), chromosomal aberration (97.6 mm³, p < 0.001) and fetal malformations (296 mm³; p < 0.001). A cyst volume of less than 2.4 mm³ was always associated with a favorable outcome regardless of the diameter of the nuchal translucency.

Conclusion: In addition to the nuchal translucency in early gestation, in case of their presence, anterolateral nuchal cysts play a significant role in predicting the fetal outcome.