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First-trimester choroid plexus to lateral ventricle disproportion and prediction of subsequent ventriculomegaly

Ultrasound Obstet Gynecol. 2023 Mar 2. doi: 10.1002/uog.26189. Online ahead of print.


OBJECTIVE: Ventriculomegaly can be associated with long-term neurodevelopmental impairment. The prenatal diagnosis of ventriculomegaly is most often made at the routine second trimester anomaly scan. The value of first trimester ultrasound has expanded to early diagnosis and screening of fetal abnormalities. The objective of this study was to assess the predictive accuracy of first trimester choroid plexus to head/ventricle ratios for development of ventriculomegaly at a later gestation.

METHODS: This was a case-control study of fetuses with isolated ventriculomegaly diagnosed after 16 weeks’ gestation. The control group included normal fetuses (without ventriculomegaly). The exclusion criteria included aneuploidy, genetic syndromes or other brain abnormalities. Stored 2D first trimester ultrasound images were blindly analyzed offline and fetal biometry measured in axial view of the fetal head. The ratios of choroid plexus to lateral ventricle area (PA/VA), choroid plexus to lateral ventricle length (PL/VL), choroid plexus to lateral ventricle diameter (PD/VD), choroid plexus area to biparietal diameter (PA/BPD) and choroid plexus area to head circumference (PA/HC) were measured at 11-13+6 weeks’ gestation. Intra- and inter-observer variability of these fetal head biometry parameters at 11-13+6 weeks’ gestation were assessed in 20 normal fetuses using intra-class coefficients with 95% confidence intervals. The accuracy of first-trimester biometric measurements for prediction of ventriculomegaly was assessed using the area under the ROC curves (AUC).

RESULTS: The analysis included 683 singleton pregnancies; of which 102 fetuses were diagnosed with ventriculomegaly. The ventriculomegaly was mild in the majority (n=86; 84.3%) of cases, while it was severe in 16 (15.7%) fetuses. All first trimester fetal choroid plexus to ventricle/head ratios were significantly lower in the ventriculomegaly cases than in controls (p<0.05 all) with good inter- and intra-observer agreement (>0.95 for the majority of the fetal head biometry assessed). After adjusting for crown-rump length, both PL/VL ratio (AUC 0.87, 95% CI 0.73-0.98) and PA/VA ratio (AUC 0.90, 95% CI 0.82-0.98) showed good predictive accuracy for severe ventriculomegaly. PA/BPD ratio (AUC 0.73, 95% CI 0.54-0.90) had modest predictive ability, which was significantly lower than prediction using PA/VA ratio (P=0.003 and P=0.001, respectively). The predictive accuracy of PD/VD ratio was low with an AUC of 0.65 (95% CI 0.46- 0.84). Optimism adjusted AUC values obtained after cross-validation showed that PA/VA ratio offered the highest predictive accuracy with an AUC of 0.90 (95% CI: 0.82-0.98), followed by PL/VL ratio (AUC 0.87, 95% CI 0.73-0.98), PA/BPD ratio (AUC 0.73, 95% CI 0.54-0.90), and PD/VD ratio (AUC 0.65, 95% CI 0.47-0.84). Optimism-adjusted AUC values obtained after cross-validation showed that PA/VA ratio offered the highest predictive accuracy for mild ventriculomegaly with an AUC of 0.83 (95% CI 0.78-0.88), followed by PL/VL ratio (AUC 0.82, 95% CI 0.76-0.88), PA/BPD ratio (AUC 0.75, 95% CI 0.68-0.81), and PD/VD ratio (AUC 0.74, 95% CI 0.67-0.80). Calibration plots show both PA/VA and PL/VL ratios have good calibration CONCLUSION: First-trimester prediction of ventriculomegaly using fetal choroid plexus to ventricle ratios appears promising. Future prospective studies are needed to validate the predictive accuracy of these ultrasound markers as a screening tool for ventriculomegaly. This article is protected by copyright. All rights reserved.

PMID:36864532 | DOI:10.1002/uog.26189

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