Ultrasound Obstet Gynecol. 2023 Oct 30. doi: 10.1002/uog.27523. Online ahead of print.
ABSTRACT
OBJECTIVE: To confirm the identity and assess the prevalence and evolution of the fluid-filled interhemispheric midline structure, potentially the cavum veli interpositi (CVI), in fetuses from 11 to 14 weeks gestation.
METHODS: A retrospective review of first trimester ultrasounds was performed over three months. Criteria included singleton pregnancies at a gestational age of 11-14 weeks gestation with known outcomes. Five experts reviewed the images. Mixed-effects logistic regression and generalized estimating equations (GEE) were conducted to analyze the associations between the first appearance of the structure and variables like scan route, maternal BMI, gestational age, CRL, and BPD. Second trimester evaluation of CNS, at 18-24 weeks gestation, for those in whom the structure was identified in the first trimester were then evaluated for its persistence.
RESULTS: Of 104 qualifying patients from the 223 reviewed, the CVI was found in 25 (24%). There was no statistically significant difference in its visualization between transabdominal and transvaginal ultrasound examinations. GEE revealed significant associations between the first appearance of the fetal structure and CRL and BPD: odds ratios of 1.32 (p < 0.0001) and 1.88 (p = 0.0011) per 10-unit increase, respectively. Maternal BMI and gestational age showed no significant effect on the first appearance of the CVI. In second trimester follow-ups, 44% still showed a CVI, 32% had a cavum vergae, 4% had both, 20% had none.
CONCLUSIONS: Based on its anatomical location and the separate visualization of the third ventricle in some fetuses, the interhemispheric midline structure visualized in the suprathalamic region of the fetal brain between 11-14 weeks of gestation is the CVI. It remained present in 80% of initially identified fetuses in the second trimester. Its presence is not linked to pathology, offering reassurance to practitioners and parents. This article is protected by copyright. All rights reserved.
PMID:37902788 | DOI:10.1002/uog.27523
