Sharp decline in IVF multiple births in Switzerland over two decades

Between 2002 and 2023, the proportion of twins born after IVF dropped from 17.4% to just 2.8%. RTS

The proportion of multiple births following in vitro fertilisation (IVF) has fallen significantly over the past two decades, largely due to a change in legislation allowing more embryos to be stored.

Between 2002 and 2023, the proportion of twins born after IVF dropped from 17.4% to just 2.8%, according to data published on Thursday by the Swiss Federal Statistical Office (FSO). The key factor behind this decline is the revised law on medically assisted reproduction, which came into force in 2017. This law allows for the storage of up to 12 embryos, enabling medical professionals to better assess which embryos should be transferred.

“This has led to a significant increase in the practice of transferring a single embryo rather than two,” said Tonia Rihs, a representative from the FSO’s reproduction section. Previously, transferring multiple embryos was more common in order to increase the chances of success, which also raised the likelihood of twins or triplets.

In 2017, more than half of all embryo transfers involved two embryos. By 2023, single embryo transfers had become the norm, with fewer than 1,000 cases involving two embryos.

Success rates continue to rise

In 2023, 6,513 couples underwent IVF treatment in Switzerland. These treatments resulted in 2,511 live births – a success rate of 30% from the 8,164 embryo transfers carried out. This figure continues to rise steadily and now accounts for around 3% of all births in the country.

Although the number of couples undergoing treatment declined slightly compared to the previous year, the number of live births increased by 5.9%. Since 2010, the number of babies born via IVF in Switzerland has risen by 25%.

+ Infertility: how Switzerland is failing many couples who want a child

Changes in legislation on the horizon

Currently, sperm donation in Switzerland is permitted but only available to married heterosexual couples or married lesbian couples. In January, the Federal Council presented a draft proposal to expand access to egg donation. If passed, it would allow unmarried couples to use both sperm and egg donation. However, surrogate motherhood will remain banned.

Some individuals who do not qualify for fertility treatments under current Swiss regulations seek help abroad, but the FSO does not collect data on these cross-border procedures. As a result, the published statistics only reflect treatments performed within Switzerland.

Translated from French using DeepL/amva/ts