Complex sentence: Hilary went to Rome, where he spent a year studying piano at the Santa Cecilia Conservatory; while Irena went to France, where she gave birth to their first child, Claude Koprowski, and worked as an attending physician at an insane asylum.
Split into simpler sentences: Hilary went to Rome, where he spent a year studying piano at the Santa Cecilia Conservatory. Meanwhile, Irena went to France, where she gave birth to their first child, Claude Koprowski, and worked as an attending physician at an insane asylum.