A Chinese government policy allowing all couples to have two children led to an additional 5.4 million births in the first 18 months after it took effect
Source:
https://www.newscientist.com/article/2214179-chinas-two-child-policy-linked-to-5-million-extra-babies-in-18-months/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home