Answer:
The term you're looking for is the "baby boom." Following the end of World War II, many parents wanted to have children as soon as possible, creating what has come to be called the postwar baby boom:
• After years of hardship and sacrifice during the Depression and the war, many Americans wanted to enjoy the fruits of peace and prosperity in the postwar period. Having children became a symbol of hope and renewal.
• Returning soldiers also wanted to start families after the disruption of the war years. This combined with a general desire for stability and "normalcy" after the tumult of the 1940s.
• New technologies like washing machines, vacuum cleaners and disposable diapers made child-rearing more manageable, while rising incomes enabled larger families.
• Government policies encouraged family formation through subsidies, tax breaks and expanded access to housing, education and healthcare.
• The result was a surge in the birth rate starting in 1946 that peaked around 1957. Over 74 million babies were born in the U.S. during the baby boom years, representing a nearly 40% increase compared to the 1930s and early 40s.
So in summary, the postwar baby boom refers to the dramatic increase in birth and fertility rates that occurred in the U.S. and other Western nations in the decade and a half following World War II. A confluence of economic, social and demographic factors combined to produce this temporary baby boom.