Counseling for Fetal Central Nervous System Defects

Abstract

Fetal central nervous system defects are one of the commonest antenatally detected abnormalities. They consist of a wide array of lesions with heterogeneous etiologies and outcomes. Counselling of the family in such cases forms an integral part of management. However, this can be challenging due to diagnostic and prognostic uncertainties for many defects. Some lesions like anencephaly, holoprosencephaly, and lissencephaly, have an invariably poor outcome, and decision regarding pregnancy termination is straightforward. On the other hand, lesions like mild ventriculomegaly, isolated corpus callosum agenesis and posterior fossa lesions have a highly variable outcome, ranging from normal to severe handicaps, hence counseling for these is difficult. Detailed sonography by an expert sonologist and fetal MRI can help in detection of additional cerebral or extracerebral abnormalities, which being associated with a poor prognosis, can help in accurate counseling. An often-neglected aspect of counseling is the possibility of recurrence in subsequent pregnancies, due to an underlying genetic etiology in many of these defects. This can be assessed by pedigree information, suitable genetic testing and postmortem examination in case of pregnancy termination. Diagnosis of the genetic abnormality helps in accurate recurrence-risk prediction as well as early and timely prenatal diagnosis in at-risk pregnancies.

Keywords

Counseling - Genetic testing - Prenatal diagnosis - Central nervous system defects

Publication History

Received: 23 January 2017

Accepted: 13 March 2017

Article published online:
08 May 2023