Evaluation of Prenatally Diagnosed Structural Congenital Anomalies

Abstract Objective To provide information to genetic counsellors, midwives, nurses, and physicians who are involved in the prenatal care of women dealing with prenatally diagnosed isolated or multiple structural congenital anomalies. Outcomes To provide better counselling for women and families who are dealing with the diagnosis of a fetal structural anomaly. Evidence Published literature was retrieved through searches of PubMed or Medline, CINAHL, and the Cochrane Library for relevant articles using appropriate controlled vocabulary (e.g., structural congenital anomalies, prenatal ultrasound diagnosis of congenital anomalies, invasive testing results, and diagnosis of genetic syndromes; soft markers of aneuploidy were not included in this search) and key words. Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. There were no date or language restrictions. Searches were updated on a regular basis and material from between 1985 and 2008 incorporated in the guideline. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. Values The evidence obtained was reviewed by the Genetics Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC). Recommendations were quantified using the evaluation of evidence guidelines developed by the Canadian Task Force on Preventive Health Care. Benefits, Harms, and Costs Findings of isolated or multiple fetal anomalies on prenatal ultrasound examination always lead to stressful times for women and families. Although a proportion of such anomalies can be explained by chromosomal abnormalities (aneuploidy, unbalanced translocation, deletions, or duplications), others may represent recognizable syndromes with another genetic basis (microdeletion or autosomal dominant, recessive, or X-linked inheritance). Providing accurate information and relevant reproductive genetic counselling to these women and families will allow them to make informed decisions. This is not easily accomplished because of the limited information available prenatally. This document does not provide an extensive description of every syndrome but rather a framework of reference. No cost-benefit analysis is provided. Recommendations 1. When a