Don't try this at home.
From the producers (2008):
If you think this is dangerous, try giving birth in poor countries without a midwife, hospital or medicine. This flashmob is one of a series happening in Paris, Berlin, Utrecht and across Canada to highlight the scandal that millions of women in poor countries and around the world aren't getting the healthcare they need for a safe and healthy pregnancy.
(And just to put your minds a rest - the dancing expectant mums in this video aren't pregnant, they were professional dancers wearing pregnancy suits!)