Prevalence and timing of pregnancy termination for brain malformations.

OBJECTIVE: To determine the prevalence and the timing of pregnancy termination relative to the type of central nervous system (CNS) malformations. Design Retrospective cohort study. SETTING: Multidisciplinary centre for prenatal diagnosis in the Languedoc-Roussillon region, France. POPULATION: A cohort of 481 pregnancy terminations performed between 2005 and 2009. METHODS: Detailed post-termination fetal and neuropathological analyses were carried out to identify the CNS malformations. Then, the prevalence and timing of pregnancy termination were assessed relative to the identified malformations. RESULTS: About one-third of pregnancy terminations (143/481) were performed for severe CNS malformations. Up to 24 weeks of gestation (WG), pregnancy terminations (56.6%) were carried out mainly for defects occurring during the two major first steps of CNS development (neurulation and differentiation of cerebral vesicles). After 24 WG, pregnancy terminations (43.3%) were mainly performed for corpus callosum agenesis (16/17), vermian agenesis (10/12) and gyral anomalies (13/15). For hindbrain malformations and gyral anomalies, there was a significant relationship between the timing of pregnancy termination and the presence of a severe ventriculomegaly at prenatal diagnosis (p=0.002 and p=0.02, respectively). CONCLUSION: By classifying CNS malformations according to the neuropathological analysis, the authors show that the timing and prevalence of pregnancy termination are distributed in a manner that is consistent with what is currently known on the development of brain. They are also influenced by the French prenatal screening policy and the variable expressivity of the brain malformations and associated lesions.

Absence of the anterior fontanelle due to a fontanellar bone.

Improved accessibility to supraregional centers in the United Kingdom has led to an increased referral of minor craniofacial anomalies. We have recognized a group of patients referred with absence of the anterior fontanelle and possible associated craniosynostosis. The aim of this study was to assess the group of patients in which the anterior fontanelle was entirely replaced by a single bone, examining associations, relationship to craniosynostosis, and prognostic implications.Eleven patients had fontanellar bones replacing the anterior fontanelle on computed tomographic imaging in the 3-year study period. Five were referred solely because of absence of the anterior fontanelle; and the remainder, because of concern of concomitant craniosynostosis. Five children had associated craniosynostosis (sagittal synostosis, 3; metopic synostosis, 1; and bicoronal synostosis, 1), 1 had acrocallosal syndrome, and 5 had no other craniofacial abnormalities. The patient group with craniosynostosis have been managed in line with the unit protocol and have good early postoperative results (mean postoperative follow-up, 9.4 mo). The 5 patients who had an anterior fontanellar bone as an isolated finding were observed and have developed normally with a mean follow-up of 2 years 1.4 months (range, 8 mo to 3 y 4 mo).Replacement of the anterior fontanelle with a fontanellar bone is an uncommon finding, often associated with craniosynostosis. Cases with craniosynostosis can be treated in line with unit protocols. Isolated anterior fontanellar bones can be managed conservatively without adverse impact on the child.