Women in the UK are offered two routine ultrasound scans, the first at 11-14 weeks of gestation, which aims to confirm viability, establish accurate gestational age, identify multiple pregnancies and certain chromosomal anomalies.
The second scan at 18-21 weeks of gestation aims mainly to detect congenital abnormalities such as spina bifida, cleft lip and serious cardiac anomalies.
Thus, anomaly detection is currently based on this second trimester anomaly scan, the results of which can have a significant impact on the management of the remaining pregnancy.
Considerable advancements in ultrasound technology in image quality, resolution and signal processing have fuelled interest in this field; given that the majority of fetal organ development is complete by 10 weeks gestation, ultrasound has the potential to be a valuable tool for early fetal structural anomaly screening.
While studies have shown that a significant proportion of major anomalies can be detected between 11-14 weeks of gestation in both low-risk and high-risk populations, there are areas of uncertainty as to the potential benefits and harms in relation to early anomaly screening using ultrasound, which this study aims to assess.
There are 4 main work streams in this study:
Conducting a series of systematic reviews to inform protocol development
Survey of the current screening environment and impact on NICE care pathway
Consensus procedure to develop a protocol for the first trimester scanning
Economic analysis and value of information (VoI) study
Staff in the NPEU will work on work stream 4 and will develop a decision analytic model to estimate the expected costs and outcomes of first trimester anomaly screening protocols and of current practice.
The model will be structured and populated using evidence from the systematic reviews, national survey, consensus procedure and from supplementary reviews of the literature and expert elicitation as required.
An NHS and social services cost perspective will be taken in the first instance, and outcomes will be considered from the perspectives of the mother, infant and both parents if data permit.
The model will explore the cost-effectiveness of the protocol and will be operationalised so as to facilitate a VoI analysis to determine if it is worth investing additional research resources and effort in a definitive randomised trial.
Progress as of 5th February 2019
We are currently on the course of conducting a systematic review of economic literature and plan to get it done by the end of March 2019.
So far, we have withdrawn data from six databases over a 20-year period.
After the title and abstract screening, we have identified 46 relevant studies and will move to the full-text review as a next step.
Based on evidence drawn from the systematic review, we will then develop a decision analytic model and present it during the NIHR HTA First Trimester Anomalies Collaborators Meeting in March.