Analysis of cystic hygroma diagnosed in the first trimester: Single-center experience

Objective: To evaluate the obstetric outcomes of fetuses with cystic hygroma other than karyotype abnormalities and structural malformations.
Material and Methods: We conducted a retrospective study based on the review of medical records of pregnant women in whom ultrasonographic diagnosis of fetal cystic hygroma was established in the first trimester from January 2014 to October 2018. All patients were offered genetic counselling and prenatal invasive diagnostic procedures to obtain fetal karyotype. For ongoing pregnancies fetal echocardiography and detailed second trimester sonographic anomaly screening was performed by a perinatologist/pediatric cardiologist. The demographic characteristics of the women and the results of the karyotype analysis were obtained from the database of our hospital and correlated with the obstetric outcomes.
Results: Within a five-year period, there were 106 cases of fetal cystic hygroma. Of those, fetal cardiac malformations were detected in four and micrognathia in one fetus. Eighty-five women underwent fetal invasive procedures and karyotype abnormalities were detected in 52 of the cases. Fetal outcomes of 33 cases with normal karyotype and 21 cases in whom karyotyping analysis were not performed due to patient refusal were enrolled into the study. Obstetric outcomes of 21 women who refused karyotyping consisted of 13 livebirths, seven missed abortions, and one fetal death, whereas those of 33 women with normal karyotype were; 12 livebirths, 12 missed abortions, two hydrops fetalis, and five fetal deaths. Nineteen of 33 fetuses with a normal karyotype and eight of 21 fetuses in whom karyotyping was not performed were terminated.
Conclusion: The presence of cystic hygroma carries a high risk for fetal karyotype abnormalities and cardiac malformations. The postnatal outcomes of the fetuses with cystic hygroma appeared to be correlated with the absence of structural malformations and karyotype abnormalities.