[Fetal ventriculomegaly: diagnosis using magnetic resonance imaging and its prognosis].

OBJECTIVE: To evaluate the diagnostic value of magnetic resonance imaging (MRI) on fetal ventriculomegaly identified through prenatal ultrasonography and the outcomes of these newborns were followed up.

METHODS: From March 2006 to July 2008, MRI was performed on 135 pregnant women whose fetuses diagnosed as fetal ventriculomegaly at an average of 32 gestational weeks in Shengjing Hospital Affiliated to China Medical University. Mild ventriculomegaly was defined when the width of unilateral or bilateral fetal cerebral ventricle triangle was 10-15 mm, moderate ventriculomegaly 16-20 mm and severe ventriculomegaly >20 mm. We introduced the Denver developmental screening test (DDST) to follow-up the mild ventriculomegaly and normal babies, confirmed by MRI, at 6-12 months after birth and a case-control study was conducted. The intelligence and growth of these infants were analyzed.

RESULTS: (1) Diagnostic rate of fetal ventriculomegaly through MRI: Among the 135 gravidas, 60 (44.4%) showed isolated ventriculomegaly, 5(3.7%) complicated with ventricular hemorrhage; 12 (8.9%) complicated with agenesis of corpus callosum (ACC) and 2 (1.5%) complicated with cerebellar hypoplasia, while 56 (41.5%) were normal. Seventy-nine cases had fetal ventriculomegaly on MRI and 15.2% (n = 12) of them complicated with ACC. (2) Degree of fetal ventriculomegaly on MRI: Among the 60 isolated ventriculomegaly cases, 55 (91.7%) were mild and 5 (8.3%) moderate ones. Among the 5 cases complicated with ventricular hemorrhage, one was mild ventriculomegaly, and 4 moderate or severe cases. Among the 12 cases with ACC, 8 (66.7%) were moderate ventriculomegaly and 4 (33.3%) severe cases. The 2 cases with cerebellar hypoplasia were both moderate ventriculomegaly fetuses. (3) Follow-up at 6-12 months after birth: thirty out (case group) of the 55 isolated ventriculomegaly cases, 38 out of the 56 normal babies and 42 babies with normal MRI results were followed up, and the later 80 cases were taken as control. Four infants (13.3%) in the case group and 10 (12.5%) in the control group showed abnormal or suspected results in DDST (P > 0.05), the rest babies were all normal. (4) Clinical outcomes of the 79 ventriculomegaly fetuses diagnosed by MRI: thirty mild ventriculomegaly babies and 5 moderate ones were born at term and showed normal at follow ups. However, 7 gravidas were not compliant, 6 pregnancies were terminated, and 12 were lost. Three of the 12 cases with ACC continued the pregnancy, and postnatal MRI of the babies showed the same with the prenatal MRI, 8 pregnancies were induced and one was lost. All of the 5 fetuses with ventricular hemorrhage were induced and the prenatal diagnosis was confirmed by autopsy. One of the 2 fetuses with cerebellar hypoplasia was term delivered and diagnosed as cerebral palsy at the age of 6 months, and the other one was induced.

CONCLUSIONS: MRI is an indispensable complementary diagnostic method for fetal ventriculomegaly diagnosed through ultrasound. The development of intelligence and growth of babies born with mild isolated ventriculomegaly is the same as normal ones.