Clinic A tells their story

Clinic profile:

• 650 IVF cycles per annum
• NHS (60%) and self funding cycles (40%)

Pre-January 2009:

• Majority day three transfers.
• 30 percent of patients had embryos frozen if they qualified on day three
  (three or more good quality embryos).
• Multiple birth rate (MBR) was 22% in 2007

The clinic felt that from analysis of our patient data it was clear that we could reduce the MBR further to meet future HFEA targets.

Policy change (January 2009)

To try to counteract a fall in pregnancy rates by utilising embryos with a higher implantation potential a policy decision to move to blastocyst transfer was made. 

A patient management algorithm based on the ACE/BFS guidelines (Cutting et al 2009) was introduced and patients meeting the criteria were strongly and consistently encouraged to consider elective single embryo transfer (eSET) at all points along the patient pathway.

Patient attitude

Uptake at first was low but by August over 60% of patients having blastocyst transfer had an eSET. 

Initial results

• Numbers are too low to statistically analyse but since the policy change overall our pregnancy rate for eSET blastocysts is 45%.
• However, for patients who go against our advice and consent to a two blastocyst transfer, the pregnancy rate is 10% higher but the twin rate is 38%. 

Link with blastocyst quality

In April the nationally recommended blastocyst grading scheme was introduced (Cutting et al 2009).  This coincided with an increase in the pregnancy rates (graph 1).

Graph 1: eSET blastocyst clinical pregnancy rates

 

Although numbers are small, our data initially shows:

• One top quality blastocyst replaced - chance of pregnancy is 54%,
• Replacing 2 top quality blastocysts does improve the chance of pregnancy although not significantly, but the twin rate increases to 36%.
• If no top quality blastocysts are available the pregnancy rate drops to 16%.  

Impact of the policy

During this time period overall the percentage of patients having eSET doubled but the multiple rate only decreased by 1% (Table 1). This was disappointing as we had moved to a firm commitment to reducing the MBR.  Analysis of the data of those with a twin pregnancy highlighted that 56% of them would have been eligible for eSET.

Table 1:  Overall impact on the policy on the MPR

Future improvements

Being able to show patients data enables them to be more comfortable with their decisions and we are now starting to use not only patient criteria but blastocyst quality as a predictor of pregnancy and MBR.

With the introduction of blastocyst vitrification and very promising early results the data set will be soon be able to show cumulative rates, as introducing blastocyst embryo transfer has not decreased the percentage of patients having embryos frozen (35%).

Conclusion

Over the last 9 months our policy has had to be adapted and the systems tweaked to ensure the correct patients are selected for eSET so as not to compromise pregnancy rates. Our system has shown that implementing blastocyst transfer can actually increase the chance of a twin pregnancy if eSET is not implemented in the selected patient group.

To make further progress we now have to provide robust data to patients, blastocyst grading will be considered within the algorithm and the team will be actively encouraging the group at high risk from twins. There is also a need for continual data analysis to develop the strategy further.