Implementing noninvasive prenatal fetal sex determination using cell-free fetal DNA in the United Kingdom.

INTRODUCTION: Fetal sex determination has traditionally been performed in pregnancies at risk of sex-linked genetic conditions by analysis of chorionic villi or amniocytes following invasive tests. The development of noninvasive prenatal diagnosis (NIPD) using cell-free fetal DNA in maternal plasma has allowed women to have accurate information about fetal sex early in pregnancy without the risk of miscarriage. AREAS COVERED: In the UK, NIPD for fetal sex determination has been offered on a research basis since 2003. Formal approval and regulation through national bodies is essential to ensure standardized laboratory services, appropriate funding and equity of access for service users. Here we describe the process of formal commissioning that has been supported by a multifaceted approach to service evaluation, including appraisal of analytical and clinical validity, clinical utility and economic costs together with an exploration of service users' and providers' attitudes, preferences and information needs. EXPERT OPINION: Implementation strategies that reach beyond the assessment of laboratory test parameters to consider psychosocial and economic issues have been crucial in bringing NIPD for fetal sex determination into routine practice. Ongoing audit and monitoring of service delivery will ensure a high standard of care is maintained.