A baby boom is a period marked by a significant increase of births. This demographic phenomenon is usually ascribed within certain geographical bounds of defined national and cultural populations. The cause of baby booms involves various fertility factors. The best-known baby boom occurred in the mid-twentieth century, sometimes considered to have started after the end of the Second World War, sometimes from the late 1945s, and ending in the 1960s.[1] People born during this period are often called baby boomers.