(704) Equity in First Trimester Congenital Anomaly Detection: Population Based Analysis in >1million women in England

As there is no unified policy for first trimester anatomical screening in England, our aim was to establish whether differences in screening methods impact on the timing of diagnosis of major congenital anomalies.

Study Design:

We linked data from two sources: a nationwide survey of current first trimester practice distributed to all NHS maternity units in England (n = 131) that established current first trimester ultrasound practice; and data from the National Congenital Anomalies Disease Registry (NCARDRS) database. The proportion of major anomalies diagnosed prior to 16 weeks gestation was then evaluated based on current first trimester screening policy.

Results:

We included 1,030,224 pregnancies including 5,598 fetuses with one of 14 major conditions. Overall, n=1,929 (32.7%, 95% CI 31.5–33.9) of these anomalies were diagnosed < 16 weeks. The screening policy in the 110 responding was grouped into four first trimester anatomy screening policies: A. no routine evaluation (n=27), B. basic (n=22), C. intermediate (n=45), and D. advanced assessment (n=16). Early detection rates were lowest in Group A (27.7%, 95% CI 25.4 – 30.0) and an increase in detection was seen in Group B (31.2%,  95% CI 28.5 – 34.1), C (33.2%, 95% CI 31.3 – 35.2) and D (40.4%, 95% CI 37.3 – 43.4, p< 0.0001).

Conclusion:

Most NHS hospitals in England offer women some form of first trimester anomaly screening. The absence of national recommendations means there are significant variations in practice, which are associated with differences in fetal anomaly detection rates prior to 16 weeks gestation at population level. Centres with clear protocols for first trimester fetal anomaly screening have higher early detection rates for major congenital anomalies. The differences in the standard of antenatal screening care offered to women across England has resulted in regional and local inequities in maternal care.