Isolated Choroid Plexus Separation on Second‐Trimester Sonography

Abstract

Objective. This study was undertaken to investigate the natural history and clinical importance of choroid plexus separation (a ≥3 mm distance between the choroid plexus and medial wall of the lateral ventricle) as an isolated finding in the second trimester. Methods. This was a 5-year retrospective review of an ultrasound database, looking for singleton fetuses with a menstrual age of 16 to 26 weeks and a finding of isolated choroid plexus separation. Results. There were 78 cases available for study. The finding of choroid plexus separation was usually transient. Resolution was noted in 37% of the cases that were rescanned within 2 weeks and 71% of the cases that were rescanned more than 2 weeks after the initial diagnosis. Two abnormal karyotypes (trisomy 21 and 47,XXY) and 3 cases with abnormal development not associated with an abnormal karyotype were noted on neonatal followup. Cases with abnormal development were quite varied in their presentation. Conclusions. The finding of isolated choroid plexus separation is usually temporary, resolving in most cases within 4 weeks of the initial diagnosis. Most infants with this finding have no abnormalities. The clinical implication of the lone case of trisomy 21 was limited by a major preexisting risk in this patient. The 3 cases of abnormal development had varying presentations; the causal nature of this association is not yet clear. No trends were noted between the changing choroid plexus appearance with time and abnormal neonatal outcome, but the number of abnormal cases was quite limited.

Bifid choroid plexus: Always a normal fetal brain structure variant?

“…Indeed, a separation of 3 mm or greater between the choroid plexus and the medial ventricular wall is associated with an increased risk of an abnormal outcome, even in fetuses with normal-sized ventricles. We measured the distance between the medial ventricular wall and choroid plexus body, and found that the distance was less than 3 mm in all cases except two Bronsteen et al 2006).…”

Choroid plexus separation in fetuses without ventriculomegaly: Natural course and postnatal outcome

“…They also found that fetuses with a lateral ventricular diameter of 12 mm or less had a good prognosis in the postnatal period. However, the number of reported studies that have investigated the postnatal outcome of choroid plexus separation without ventriculomegaly is limited …”

“…A separation between the choroid plexus and the mediolateral ventricular wall of less than 3 mm is accepted as normal. However, a choroid plexus separation greater than or equal to 3 mm is reported to be associated with fetal chromosomal and developmental abnormalities …”

“…Previous studies reported that choroid plexus separation with mild ventriculomegaly (atrial width of 10–15 mm) is associated with chromosomal abnormalities or other pathology . However, a limited number of investigators have studied the effects of choroid plexus separation without ventriculomegaly on fetal outcome, and the importance of this condition is still unclear.…”

Detailed ultrasound screening in the second trimester: Pictorial essay of normal fetal anatomy

“…Other findings of ventriculomegaly include separation of the choroid plexus from the medial ventricular wall (≥3 mm distance) (Figure 1B) 9. However, the finding of isolated choroid plexus separation is generally temporary, resolving in most cases within 4 weeks of the first diagnosis 10…”