Presence of chromosomal abnormalities in fetuses with isolated ventriculomegaly on prenatal ultrasound in China.

Background: The purpose of our study was to compare the incidence of chromosomal abnormalities of fetuses with isolated fetal ventriculomegaly (VM) to that of fetuses with the sole risk factor of being born to mothers of advanced age.

Method: This prospective study included two groups. Group 1 included fetuses with isolated VM and were further categorized according to maternal age, fetal gender, laterality of VM (unilateral or bilateral), evolution of VM (resolved or persistent or progressive), and the gestational age at the time of diagnosis (<28w or ≥28w). Group 2 were fetuses without any fetal structural abnormality, but maternal age was at or over 35 years.

Result: Eighteen fetuses (18/231, 7.8%) with chromosomal abnormalities were identified for Group 1, and 13 fetuses (13/782, 1.7%) were identified for Group 2. When cases with mothers of advanced age were excluded from Group 1, the incidence of chromosomal abnormalities of isolated VM fetuses age was 7.2%, which is still higher than that of normal structural fetuses in mothers of advanced age (p < 0.001).

Conclusion: The risk of chromosomal abnormalities for fetuses with isolated VM is high, especially when it is severe, bilateral, the first presence occurs in mid-gestation and is not resolved.