Neuroimaging safety during pregnancy and lactation: a review

Imaging studies are crucial adjuncts when studying acute and chronic diseases, so pregnant and lactating women are as likely to be evaluated with one of the available imaging modalities. Due to the specific condition of the mother and child in this time period it is crucial to make an appropriate selection of imaging studies.

We review the existing literature and analyse the latest evidence and guidelines regarding neuroimaging safety during pregnancy and lactation, proposing an algorithm of action based on risk/benefits assessment.

Choosing the most appropriate neuroimaging modality implicates assessing the pretest pertinence of the study-the possibility of a serious treatable neurologic disease, pondering what is the most useful imaging modality for the diagnosis and evaluating the associated risks. Among physicians (and patients), however, the risk component is perhaps the least well understood, with misperceptions regarding safety and potential hazards. Computed tomography (CT) risks are principally related to ionizing radiation and intravenous (IV) administration of iodinated contrast. However, as very low risks for the mother and foetus have been reported and CT remains the most available tool for initial rapid diagnosis of acute neurological conditions, it should not be withheld in urgent situations. Magnetic resonance imaging (MRI), unlike CT, does not use ionizing radiation or iodinated contrast mediums, having the best anatomical detail possible. However, there are some usage safety concerns regarding the magnetic field strength and gadolinium-based contrast use.

There are lacking longitudinal and prospective studies to sustain evidence based choices of imaging studies during pregnancy and lactation. Ultimately the decision should be based on the risk/benefit, taking into account the patient's safety, care and outcomes. However, using a specific algorithm can guide decisions in daily clinical practice.