Analysis by the European Society for Human Reproduction and Embryology's (ESHRE's) European IVF Monitoring Consortium showed that 2016 pregnancy rates per treatment started were 27.1 percent with IVF, and 24.3 percent with ICSI.
'There is a small decline in pregnancy rates in IVF and ICSI in fresh cycles for 2016 compared with 2015,' said Professor Christian de Geyter, chair of the consortium presenting the annual results at ESHRE's annual meeting in Vienna, Austria. 'In contrast we have a slight rise in frozen embryo replacement (FER) cycles.'
There has been a shift towards frozen embryo replacement by many clinics in recent years. This is when embryos are frozen and then thawed and transferred later; in fact some clinics have moved to a 'freeze-all' strategy for fertility treatment (see BioNews 1003 and 964).
'The number of FER is increasing very rapidly and has now bypassed the number of IVF cycles done,' said Professor de Geyter. 'The number of fresh treatment cycles is declining.'
The increase in FER may be due in part to more clinics transferring one embryo at a time, meaning that more are frozen for subsequent transfers. The report found that over 40 percent of transfers were a single embryo, compared with 11 percent in 1997, and that twin births account for around 15 percent of IVF births, a figure which is continuing to decline.
Overall, the analysis covered data from more than 800,000 treatment cycles 36 countries (the UK has yet to deliver its data).
'The European champion in 2016 has been Spain,' said Professor de Geyter. A record 140,909 treatment cycles were performed in the country. 'Second in line is Russia and third in line is France,' he added.
The data 'reveals some worrying trends in fertility treatment' said Sarah Norcross, director of the Progress Educational Trust (the charity which publishes BioNews).
While the number of babies born through assisted reproduction in 2016 was 'heartening', she said 'it is concerning that around half of all treatment cycles are now with frozen embryos, and ICSI is used nearly three times as much as IVF (359,858 ICSI, 128,626 IVF cycles)'.
She added: 'To date, there is no definite data to support the use of frozen embryo transfer instead of fresh embryo transfer in all fertility patients, and neither is there any robust evidence supporting the use of ICSI, rather than IVF, when patients do not present with male factor fertility problems.'