Development and evaluation of training resources to prepare health professionals for counselling pregnant women about non-invasive prenatal testing for Down syndrome: a mixed methods study.

BACKGROUND: The availability of non-invasive prenatal testing (NIPT) for aneuploidies is expanding rapidly throughout the world. Training health professionals to offer NIPT in a way that supports informed choice is essential for implementation. The aim of this study was to develop and evaluate a training package for health professionals to support the introduction of NIPT into clinical practice. METHODS: Training on NIPT was offered to health professionals, primarily midwives, involved in Down syndrome screening and testing in eight hospitals located in England and Scotland as part of a research study evaluating the implementation of NIPT in the UK National Health Service. Training was evaluated using a mixed methods approach that included quantitative questionnaires at three time points and post-training qualitative interviews. The questionnaires measured confidence, self-perceived knowledge and actual knowledge about NIPT for Down syndrome. Interviews explored opinions about the training and experiences of offering NIPT. RESULTS: The training provided to the health professionals was found to positively impact on their confidence in discussing NIPT with women in their clinic, and both their perceived and actual knowledge and understanding of NIPT was improved. Knowledge remained weak in four areas; cell-free fetal DNA levels increase with gestation; turnaround time for NIPT results; cell-free fetal DNA is placental in origin; and NIPT false positive rate. CONCLUSIONS: Training materials, including a lesson plan, PowerPoint presentation and written factsheet on NIPT, have been developed and evaluated for use in educating midwives and supporting the introduction of NIPT. Implementation of training should include a greater focus on the areas where knowledge remained low. Some groups of midwives will need additional training or support to optimise their confidence in discussing NIPT with women.

Routine testing of fetal Rhesus D status in Rhesus D negative women using cell-free fetal DNA: an investigation into the preferences and information needs of women.

OBJECTIVE: The goal of this study is to investigate women's preferences and information needs for routine implementation of fetal Rhesus D (RhD) typing using cell-free fetal DNA. METHODS: A questionnaire was developed following focus groups and interviews with both health professionals and RhD negative (RhD-) women offered fetal RhD genotyping within a research study and distributed to RhD- women attending routine antenatal appointments in four National Health Service hospitals. Current knowledge of blood types, anti-D administration, fetal RhD genotyping and future practices were explored. RESULTS: A total of 19 respondents participated in interviews and focus groups, and 270 respondents completed the questionnaires. Questionnaire respondents overwhelmingly felt that the test should be offered to all RhD- women (92.1%), and 75.9% said that they would accept this test. Most were happy to have the test even if it involved extra blood tests (89.3%) or appointments (79%). The knowledge of blood groups was poor. Although 90.7% knew that the baby could have a different blood group from themselves, only 34% knew that blood groups are inherited from both parents. More than 40% were not aware that anti-D would not be required if their baby was RhD-. CONCLUSIONS: Women would welcome the introduction of routine fetal RhD genotyping. Information leaflets and training of midwives will be essential for implementation to ensure good understanding regarding testing.

Diagnostic accuracy of routine antenatal determination of fetal RHD status across gestation: population based cohort study.

OBJECTIVES: To assess the accuracy of fetal RHD genotyping using cell-free fetal DNA in maternal plasma at different gestational ages. DESIGN: A prospective multicentre cohort study. SETTING: Seven maternity units in England. PARTICIPANTS: RhD negative pregnant women who booked for antenatal care before 24 weeks' gestation. INTERVENTIONS: Women who gave consent for fetal RHD genotyping had blood taken at the time of booking for antenatal care and, when possible, at other routine visits such as for Down's syndrome screening between 11 and 21 weeks' gestation, at the anomaly scan at 18-21 weeks, and in the third trimester when blood was taken for the routine antibody check. The results of cord blood analysis, done routinely in RhD negative pregnancies, were also obtained to confirm the fetal RHD genotyping. MAIN OUTCOME MEASURES: The accuracy of fetal RHD genotyping compared with RhD status predicted by cord blood serology. RESULTS: Up to four analyses per woman were performed in 2288 women, generating 4913 assessable fetal results. Sensitivity for detection of fetal RHD positivity was 96.85% (94.95% to 98.05%), 99.83% (99.06% to 99.97%), 99.67% (98.17% to 99.94%), 99.82% (98.96% to 99.97%), and 100% (99.59% to 100%) at <11, 11-13, 14-17, 18-23, and >23 completed weeks' gestation, respectively. Before 11 weeks' gestation 16/865 (1.85%) babies tested were falsely predicted as RHD negative. CONCLUSIONS: Mass throughput fetal RHD genotyping is sufficiently accurate for the prediction of RhD type if it is performed from 11 weeks' gestation. Testing before this time could result in a small but significant number of babies being incorrectly classified as RHD negative. These mothers would not receive anti-RhD immunoglobulin, and there would be a risk of haemolytic disease of the newborn in subsequent pregnancies.