West Middlesex University Hospital is a district general hospital, part of the Chelsea and Westminster Hospital NHS Foundation Trust. It serves patients in the London Boroughs of Hounslow, Richmond upon Thames and Ealing.
Adoption of high-throughput non‑invasive prenatal testing (NIPT) for fetal RHD genotype testing was led by a consultant obstetrician & gynaecologist following promotion by NHS Blood and Transplant (NHSBT) of the technology at a conference. As it had potential to reduce the amount of Anti D used the project lead was keen to try and implement into routine practice. Implementation was projected to be cost neutral based on the cell free fetal (cffDNA) costing spreadsheet from NHSBT.
The technology was introduced as a change in pathway rather than offered as an option, although the existing pathway remains available in the event that the woman declines the test. In this organisation the test is referred to as ffDNA, (free fetal DNA), although NHSBT refer to it as cffDNA. The local post-partum pathway changed following implementation of this technology, with cord blood samples taken only for babies with a negative ffDNA in order to confirm the rhesus-D result. For women whose babies are predicted to be Rhesus D positive, postnatal anti-D is administered without doing a cord blood sample.
Offering NIPT for all pregnant women who are Rhesus D negative is in line with NICE DG25 recommendation (1.1) and will help reduce unnecessary use of the blood product anti-D immunoglobulin. This case study has been adapted from the Adoption support for high-throughput non-invasive prenatal testing for fetal RHD genotype: insights from the NHS and reflects the service at the time of resource publication (February 2017).
Aims & Objectives
There are 5000-5500 babies delivered annually at West Middlesex University Hospital part of Chelsea and Westminster Hospital NHS Foundation Trust. The other maternity hospital in the organisation, Chelsea and Westminster Hospital has not implemented the test, however this will be considered in the future. The test is used to determine the fetal RHD genotype which then directs prophylactic treatment with Anti D immunoglobulin. This is in line with NICE diagnostic guidance High-throughput non-invasive prenatal testing for fetal RHD genotype (DG25).
Within the midwifery services at West Middlesex Hospital there are core labour ward midwives and core community midwives. Implementation of high-throughput non-invasive prenatal testing for fetal RHD genotype began in June 2016. Prior to this all pregnant women who were Rhesus D negative were treated with Routine antenatal anti-D prophylaxis (RAADP) as per NICE guidance on routine antenatal anti-D prophylaxis for women who are Rhesus D negative which recommends that all pregnant women who are D-negative are offered prophylactic anti-D immunoglobulin in the third trimester. In West Middlesex University Hospital this was offered at the 28 week antenatal appointment. The new test is now used to determine the fetal RHD genotype which then directs prophylactic treatment with Anti D immunoglobulin. This is in line with NICE diagnostic guidance High-throughput non-invasive prenatal testing for fetal RHD genotype (DG25). If the fetal RHD is negative the woman does not need prophylactic treatment with anti D, if it is positive then she will have the anti D injection at 28 weeks.
This technology aims to identify if a rhesus D negative women is carrying a rhesus D negative or positive baby, and was predicted to achieve savings on the following factors if the baby is predicted rhesus D negative:
- number of anti-D clinic appointments used
- amount of anti-D immunoglobulin ordered on an annual basis
- number of Kleihauer tests performed (test to measure the amount of fetal haemoglobin in maternal blood
Reduced use of Anti D immunoglobulin was a key factor in implementation.
The implementation team consisted of representatives from maternity services, haematology, laboratory and information technology. They prepared a cell-free fetal DNA (cffDNA) costing spreadsheet which is available from NHSBT. They presented this along with other literature from NHSBT to the clinical MDT and senior management team. The project gained support from these teams due to both the cost-savings potential and also the ethical consideration of not using unnecessary blood products. It was also considered likely to enhance the patient experience.
Implementation was delayed due to challenges with the content of the clinical information received back, and the poor interoperability between the laboratory information management system and Integrated Clinical Environment (ICE) laboratory and diagnostic information system. Following discussion with the in-house IT department, we were able to create a local programme which facilitated receipt of the required clinical information from NHSBT into our laboratory management system, for example, ensuring inclusion of the estimated date for delivery for the current pregnancy. Close liaison between the local IT, maternity and laboratory teams and NHSBT was crucial during the development of this system as this enabled the correct information to be included when results are received and transcribed. To mitigate the risk of manual transcribing errors, 2 members of staff crosscheck entry of the result into ICE.
The samples are predominately collected by the community midwives at the 16 week antenatal check-up and delivered to the labour ward at the end of their shift, in line with the existing process for laboratory specimens. Samples are sent to NHSBT twice daily on the existing transport network.
The technology was introduced as a change in pathway rather than offered as an option, although the existing pathway remains available in the event that the woman declines the ffDNA test. Efforts were made to increase the user uptake of the test with local campaigns such as:
- Identifying midwife champions at each point of the maternity pathway.
- Sending the new guidelines to each midwife directly and circulating with monthly forum minutes.
- Displaying promotional posters in offices.
- Discussing with maternity colleagues at every opportunity.
- Developing local patient information.
A sticker system was developed to record the ffDNA result on the notes as “baby positive” or “baby negative”. The absence of a sticker indicates the test was not offered or was declined, and prompts staff reviewing the woman to offer if still appropriate given the stage of gestation. If the ffDNA test result is positive, this indicates that the baby is rhesus D positive and the woman will receive anti D immunoglobulin prophylactic treatment. If the result is negative – the woman will not receive anti D immunoglobulin as per the new process. This test result will be confirmed with a cord blood sample following delivery.
Results and evaluation
Initial results based on the first 6 months of use show that of 352 ffDNA tests ,123 predicted the baby to be Rhesus negative, 210 predicted Rhesus positive and 15 were reported as ‘inconclusive treat as positive’; 4 were rejected. These are in keeping with the proportions expected.
There was a high uptake of the test amongst women, and early analysis suggests this is increasing, associated with improved staff awareness and therefore more women being offered the test now than in the initial months of use. A total of 143 D-negative women have delivered to date: 100% of ffDNA negative results match the cord blood tests. 89 ffDNA positive babies have been delivered 1 baby has tested as Rhesus negative. Cord testing of some babies predicted to be Rhesus positive is still occurring, and further education and discussion are on-going. The team plan to evaluate the cost impact 12 months post implementation.
Initial Patient Satisfaction surveys show good levels of understanding and a positive response to the new service.
Key learning points
- It is essential to check the interoperability of the various IT systems and establish links between the local IT, laboratory and maternity teams and NHSBT if changes are needed.
- Clarify content of reports at an early stage to prevent unnecessary delays.
- Collaborative working between all departments is crucial to successful implementation.
- Engage with all grades of staff. Health care assistants (HCAs) in particular played a valuable role in increasing the uptake of the test amongst patients and staff.
- Cord testing of some babies predicted to be Rhesus positive is still occurring, and further education and discussion are ongoing.