Early in the pandemic, some speculated that couples isolated together during lockdowns might produce a year-end baby boom. The opposite occurred. Five US states have provided monthly birth data through December – Arizona, California, Florida, Hawaii and Ohio – and their reports show large declines nine months after Covid-19 was declared a national emergency. More than 50,000 fewer births occurred in these states in 2020 compared with a year earlier. In California, the largest state by population, December births fell 19 per cent from a year earlier. Data gathered through July 1, 2020, revealed that the Golden State had added just 21,200 residents, the slowest rate of growth since 1900. Estimates from the state’s Department of Finance show elevated deaths – due to an ageing population and the virus – along with less international migration put a brake on population growth. “These are, to put it mildly, very larges declines in historical terms,” said Philip Cohen, a sociologist at the University of Maryland, regarding the California drop. “One thing we don’t yet know is how much of this is driven by people moving around, rather than just changes in birth rates.” The overall US birth picture could change as more states report. Study launched after Singapore baby born with Covid-19 antibodies But the initial data from the five states adds credence to a survey conducted by the Guttmacher Institute early during the pandemic which found that more than 40 per cent of women reported that because of Covid-19, they changed their plans about when to have children or how many children to have. One-third of the women surveyed said they wanted to delay pregnancy or have fewer children because of the pandemic.