More than eight million babies have come into the world thanks to fertility treatments since the first 'test tube baby', Louise Brown, was born in 1978, according to a study which was presented recently at the conference of the European Society of Human Reproduction and Embryology (ESHRE), in Barcelona.
Louise, the first baby to be born as the result of in vitro fertility treatment, was born on 25 July 1978 at Oldham General Hospital in the UK, after a conception guided by a reproductive biologist from Cambridge, Robert Edwards - who later founded ESHRE - and gynaecologist Patrick Steptoe.
The study, which shows the numbers of babies born as the result of different fertility techniques, used data collated from regional registers between 1991 and 2014.
The experts on the international committee which monitors the progress of this system have estimated that more than half a million babies are born each year as the result of different reproductive techniques; a total of two million fertility treatments are carried out every year.
The study shows that Spain is still the most active country in Europe in terms of assisted reproduction, with a record 119,875 treatment cycles registered in 2015, ahead of Russia, France and Germany.
The latest report from ESHRE, which includes all fertility treatments carried out in Europe in 2015, shows that there were nearly 800,000 cycles and 157,449 births.
Among other findings, the study shows a preference among European clinics for the intracytoplasmic sperm injection technique (ICSI) rather than in vitro fertilisation, and this pattern is reflected in the rest of the world as well.
The study also shows that the pregnancy rate for the two treatments has stabilised by 36 per cent and increases when five-day-old embryos (blastocysts) are used instead of those which are three days old.
The number of pregnancies which occur after the donation of ovules continues to rise and is now at 50 per cent, while the number of pregnancies of twins has dropped in Europe, to 14 per cent in 2015.
The president of the ESHRE committee, Christian de Geyter, explained that "the success rates have stabilised, although there is continuing progress from ovule donation and the use of frozen embryos".
Nevertheless, the greatest increase has been from treatments using frozen ovules, propitiated by the vitrification technique all over the world.
According to De Geyter, the availability of fertility treatments is still "very uneven" in Europe, with Denmark and Belgium offering over 2,500 treatment cycles for every one million inhabitants, whereas other countries such as Austria and Italy offer "considerably fewer".