Audit & Research

Audit Introduction

Background to MUMS MUMS was created in November 2003 by Chris Griffin and Mike Wyldes, two consultant obstetricians and gynaecologists. Chris is also a fetal medicine sub specialist and Mike governs the regional birth defects register as well as being the deputy lead for the West Midlands Perinatal Institute and joint obstetric lead for the regional neonatal network group.

Both are consultants within the Heart of England NHS Foundation Trust, the largest maternity trust in the UK.

The creation of MUMS was driven by an increasing demand by patients for a service not offered within the NHS of the West Midlands.

Furthermore, the pace of patient awareness of screening and knowledge of pregnancy increased beyond that of the NHS service staff. MUMS provided a self referral secondary service for pregnant women. Also, the advances being made in first trimester scanning and screening were at a pace that could not be instituted within the NHS due to lack of resources, appropriately trained staff and time. Methods – nuchal scan In 2003 we used the combined nuchal scan and maternal serum measurement of two hormones – BHCG and PAPP-A. The performance of this test from an international survey has shown detection rates for pregnancies affected with Downs of 85% with a 5% false positive rate.

In 2004 we started to train staff in the use of the ductus venosus Doppler waveforms for the detection of Downs syndrome (DS). Preliminary data showed that this may be a valued screening tool for detecting DS. However, this tool has not been incorporated into the screening service. This is probably due to the difficulty reproducing the findings between practitioners.

In 2005 we started to look train all staff in visualising the nasal bone (NB) for the detection of DS. Studies had shown that including the absence of presence of the nasal bone in the screening program increased the detection rate to 90% and a false positive rate of 3%. At present all our staff are now accredited in the use of the nasal bone for DS and this tool is incorporated into the equation for DS screening.

In 2006 we started training staff in the use of tricuspid regurgitation (TR). Studies indicated that this tool was as effective as the nasal bone in screening for DS. All staff bar one in the practice are now accredited in this methodology with the remaining staff member awaiting the outcome of the examination for accreditation. This tool is now incorporated into the calculation package for DS screening.

Over this period of scanning we have been perfecting our own anatomy scan for other structural problems which would not normally be detected until the 20 weeks anatomy scan. Studies show that up to 70% of all major detectable birth defects can be excluded by a detailed scan at 11 to 14 weeks. This part of the service has not been fully audited yet but will be over 2007.

Thus we now combine 6 methods in screening for DS between 11 and 14 weeks

  1. Maternal age
  2. Nuchal Thickness
  3. Maternal hormones – BHCG and PAPP-A
  4. Tricuspid regurgitation
  5. Detailed anatomy scan of the fetus
  6. Nasal bone presence
In May 2006 we changed our risk calculation to reflect the risk at term from the risk for chromosomal problems at the time of the scan. This was in keeping with practice across the nation within the NHS. Methods – audit of pregnancy outcomes There were numerous methods used to determine outcomes for the pregnancies
  1. all patients were given a stamped addressed audit card at the consultation for the screening to be returned after the pregnancy was completed. In this card are areas to examine the essential birth data, the diagnoses of chromosomal or birth anomalies and comments upon the service we provided.


Failure to receive the audit card 6 months after the assumed due date for birth the following was undertaken;
  1. all high risk patients ie a risk of greater than 1 in 250 were identified and phoned for outcomes of the pregnancy. Letters were sent to all other patients
  2. emails were sent to all screening midwives asking for feedback on any patient they were aware had visited MUMS during the index pregnancy
  3. the MUMS database was cross referenced with national and regional databases in an anonymous manner ie maternal DOB, date of scan and postcode to determine outcomes for pregnancies affected with Downs syndrome. This included pre and post natal samples for the patient or baby from the cytogenetics laboratory
  4. patients returning to MUMS in subsequent pregnancies were asked about outcomes of previous pregnancies
  5. GP surgeries were contacted where we could not contact patients for outcomes of pregnancies where invasive testing had been undertaken
  6. where patients had recommended to friends to use our service we asked the attending friend the outcome of that persons pregnancy whilst at the same time not releasing any information to the friend about the pregnancy in question
  7. BT online directory of enquiries was used to find new phone or correct phone numbers
  8. Screening midwife co-ordinators were contacted to ascertain outcome data for patients delivering at hospitals
Only patients who were scanned and tricuspid regurgitation or normality was confirmed were included in the formulation of the false positive risk assessment.

The outcome data for 2007 is obviously incomplete so no data for this is included in the formal results for the preceding years.

Cross reference to the regional cytogenetics laboratory where all chromosomal studies for the West Midlands are performed was undertaken to ascertain outcomes for our audit. Data for comparing the triple test to the first trimester screening was obtained from Mrs Vicky Edwards at the regional biochemical screening service at the Women’s hospital.