Complex sentence: In December 2012, it was announced that Catherine and William are expecting their first child, following the duchess' three-day hospital stay and diagnosis with hyperemesis gravidarum, a form of acute morning sickness.
Split into simpler sentences: In December 2012, it was announced that Catherine and William are expecting their first child. The announcement followed the duchess' three-day hospital stay and diagnosis with hyperemesis gravidarum, a form of acute morning sickness.