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

Dan Zhao,Xiaodan Lu,Bing Wang,Lu Meng,Ailu Cai

doi:10.1002/mgg3.477

Abstract

BackgroundThe 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.MethodThis 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.ResultEighteen 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).ConclusionThe 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.

Highlights

(VM) is the most commonly identified abnormal cerebral finding by prenatal ultrasound, defined as the maximum width of the atrium of the lateral ventricle being greater than or equal to 10 mm
Gezer detected a higher incidence of chromosomal abnormalities when VM was isolated (8.6%) rather than associated with any anomaly (3.8%), suggesting that karyotype analysis should be performed in all patients (Gezer et al, 2014)
We identified 7.8% of chromosomal abnormalities in cases with isolated VM, with trisomy 21 being the most commonly detected chromosomal abnormality (6/18, 33.3%)

Summary

| INTRODUCTION

(VM) is the most commonly identified abnormal cerebral finding by prenatal ultrasound, defined as the maximum width of the atrium of the lateral ventricle being greater than or equal to 10 mm. The incidence of associated anomalies in fetuses with VM is high, about 50% according to the previous studies Some of these malformations could be identified by ultrasound, such as open neural tube defects; some may be only recognizable by MRI, such as cortical malformations. Recent improvements and standardizations of fetal screenings, we can better determine the incidence of chromosomal abnormalities in cases with isolated VM. Our study was designed to compare the incidence of chromosomal abnormalities of fetuses with isolated fetal VM and that of fetuses with the sole risk factor of advanced maternal age, with the intent of using these data for future prenatal counseling in pregnancies with isolated VM. If any fetal structural abnormality was identified in the follow‐up US or MRI, cases were excluded from the study. A chi‐square (or Fisher's exact test as appropriate) test was used to compare frequencies between categorical variables and groups with a p‐value ≤0.05 considered as statistically significant

| RESULTS

Findings

| DISCUSSION