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P17At what gestational age can the corpus callosum and cavum septi pellucidi be regularly seen at routine obstetrical ultrasound examination?
Author(s) -
Toi A.
Publication year - 2000
Publication title -
ultrasound in obstetrics and gynecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.202
H-Index - 141
eISSN - 1469-0705
pISSN - 0960-7692
DOI - 10.1046/j.1469-0705.2000.00004-1-17.x
Subject(s) - corpus callosum , agenesis of the corpus callosum , medicine , agenesis , gestation , fetus , gestational age , sagittal plane , anatomy , obstetrics , pregnancy , biology , genetics
Background Agenesis of the corpus callosum (ACC) is reported to be difficult to detect before 22 weeks gestation. However, the cavum septi pellucidi (CSP) develops with the CC and is seen by 15–16 weeks. Thus, ACC should be detectable by 16 weeks. Purpose To determine at what gestational age the cavum septi pellucidi and corpus callosum become regularly visible and hence ACC can be suspected if they are not visible. Methods Fifty consecutive women referred for US for all indications between 25 June and 9 July 1999 were scanned trans‐abdominally with specific attempt to see the cavum septi pellucidi (CSP) and the corpus callosum. Results BPD ranged from 32 (15.6 week) to 81 mm (33.1 week). The CSP was visible in every fetus starting at BPD 34 mm (16.2 week). On mid sagittal views the CC was also visible starting at BPD 34 mm (16.2 week) in all but 3 fetuses due to fetal position. The CC was seen well enough to confidently measure its length in 27/49 (55%). Conclusions At routine examination, the CSP was detectable by 16.2 week (BPD 34 mm) gestation and in every pregnancy after this age. Using only trans‐abdominal scans, the CC was visible on sagittal views by exploiting access provided by sutures and fontanelles. Detection of complete agenesis of the corpus callosum should be possible by 16 weeks gestation.