Impact on informed choice of offering antenatal sickle cell and thalassaemia screening in primary care: a randomized trial.

Objectives: Offering antenatal sickle cell and thalassaemia (SCT) screening early in pregnancy can maximize the range of post-screening choices available, however these benefits should not be obtained at the expense of informed choice.  This study examined whether offering this screening in primary care at the time of pregnancy confirmation compromises women making informed choices. Design Partial factorial, cluster randomized controlled trial.

Setting: 25 general practices in two socially deprived UK areas. Participants 464 pregnant women offered antenatal SCT screening. Intervention Practices were randomly allocated to offer pregnant women screening:  i) in primary care at time of pregnancy confirmation, with parallel partner testing (n = 191), ii) in primary care at time of pregnancy confirmation, with sequential partner testing (n = 158), or iii) in secondary care by midwives, with sequential partner testing (standard care, n = 115). Main outcome Informed choice - a classification based on attitudes, knowledge and test uptake.

Results: 91% of woman underwent screening. About a third (30.6%) made an informed choice to accept or decline screening: 34% in primary care parallel group; 23.4% in primary care sequential and 34.8% in secondary care sequential. Allowing for adjustments, rates of informed choice did not vary by intervention group: secondary care versus primary care with parallel partner testing OR 1.07 (95% CI 0.56 to 2.02); secondary care versus primary care with sequential partner testing OR 0.67 (95% CI 0.36 to 1.25).  Uninformed choices were generally attributable to poor knowledge (65%).

Conclusion: Offering antenatal SCT screening in primary care did not reduce the likelihood that women made informed choices. Rates of informed choice were low and could be increased by improving knowledge.