The first successful in-vitro fertilisation (IVF) in Slovenia was performed 40 years ago and today about a thousand babies born every year in the country are conceived outside the body. Slovenia is considered to be a global leader in the field.

In March 1983 gynaecologist Tomaž Tomaževič and microbiologist Helena Hren Vencelj visited Erlangen, Germany, to learn how to perform IVF. Six months later the first woman was made pregnant using the same method in Ljubljana.

Helena Ban Frangež, the head of the reproduction ward at the Division of Gynaecology and Obstetrics at the UKC Ljubljana medical centre, recalled the beginnings as an exhibition marking the anniversary opened at the UKC Ljubljana lobby on 15 March.

Tomaževič, one of Slovenia's IVF pioneers, is happy with the progress the UKC Ljubljana's gynaecology department has made since he retired in 2013. "We can proudly say we're at the very top globally," he told the STA.

He is still enthusiastic about IVF as he often meets couples whom he helped conceive, and their offspring.

Today around 5% of children in Slovenia are conceived outside the body, which means some 1,000 babies annually, said Vesna Šalamun, head of the unit for medical services at the Ljubljana UKC Division of Gynaecology and Obstetrics.

They have not only successfully transferred know-how from abroad to Slovenia but also significantly contributed to IVF development, said Frangež.

It was Ljubljana that started developing a medium for freezing blastocysts, or embryos, which has considerably changed the applicability of IVF globally, she said.

This new freezing method introduced in 1994 made it possible to insert fewer embryos into the womb and thus reduce the number of multiple pregnancies, said Martin Štimpfel, the head of the lab at the Ljubljana gynaecology department.

The next major milestone was introduction of a new method of embryo freezing in 2003 and the latest method of freezing was introduced in 2014.

Štimpfel says milestones in this field come every ten years, but he feels a kind of a plateau has been reached. He now expects progress in non-invasive evaluation of embryo quality and the use of AI to choose the most suitable sperm and the best embryo for IVF.