Complex sentence: The story of the carrier began when Håkan came back from maternity leave in 1991, at the same time as BabyBjörn got in contact with Ergonomidesign to start a collaboration.
Split into simpler sentences: The story of the carrier began when Håkan came back from maternity leave in 1991. At this time BabyBjörn got in contact with Ergonomidesign to start a collaboration.