Kat Athanasiades and her husband had planned to have a second child right around when their daughter turned 2, which meant trying to get pregnant in March or April 2020. But then the world turned upside down.

When the coronavirus pandemic hit, the couple, who live in the District’s Columbia Heights neighborhood, began to reassess. Both had switched to remote work, their nanny share was suspended, and the social network on which they relied had receded. The prospect of giving birth in a hospital during the pandemic also felt daunting; Athanasiades recalled stories of women “delivering solo with masks or being separated from your baby if you were positive.”

“We were isolating,” she said, “so we didn’t have any support at all. We furloughed our nanny, so it was my husband and I doing all the care for an active 18-month-old. Putting our daughter to bed one night, I said, ‘I don’t think we can have another right now. … I don’t think I can do it when I’m so uncertain of what our future’s going to look like.’ ”

She was not the only one. A recent Brookings Institution study shows 60,000 fewer births than expected between October 2020 and February 2021 in the United States, corresponding with fewer conceptions earlier in 2020. The largest number of missing births were in January 2021, which roughly corresponds to conceptions in April 2020, when many Americans began to process the magnitude of the pandemic.

“Uncertainty is not good for fertility,” said Phillip Levine, a professor of economics at Wellesley College and co-author of the report. “You want to know that when you’re bringing a child into the world, you’re going to be bringing the child into an environment that’s safe and secure, and if you can’t forecast that, that’s when things will be, ‘Maybe now is not the right time.’ ”

The dip corresponds with declines in births during past recessions and public health crises, such as the Great Recession and the 1918 flu pandemic, which came in waves, Levine said.

“What was interesting about Spanish flu is there were three significant spikes in death rates and there were significant dips in births nine months after each of these spikes,” he said.

By the summer of 2020, conceptions returned to expected levels but did not rise enough to compensate for the missing births earlier in the year. Once additional data becomes available, the researchers plan to measure the effects on births of the coronavirus spike from the winter of 2020-2021 and those related to the delta variant; the impact of the current, omicron surge could follow.

The study found that the decline was not the same across the board. Births fell 3.7 percent on average across states, but in states such as New York, Massachusetts, New Hampshire and Delaware, the dip was much sharper. Births to residents of New York City, which was hit particularly hard early in the pandemic, declined 23.4 percent nine months later, the researchers estimated.

States with larger spikes in unemployment rates early in the pandemic tended to have larger decreases in birthrates nine months later, as did states with more covid cases per capita, the study found.

But the missing births were not necessarily directly related to personal hardship; for some, the general state of affairs was worrying enough, Levine said.

“Psychology is an important factor,” he said. “You might not be a front-line worker, you might not have lost your job, yet you still are scared. You could be more worried about the health implications of being pregnant and being exposed to covid, or the ability of the medical care system to handle the demand and tend to your needs.”

The biggest birthrate declines were among more highly educated women, women who already had at least one child and women in their late 30s and early 40s.

Women in that age category are more likely than younger ones to need assisted reproductive technology (ART) to conceive and stay pregnant, and many fertility clinics suspended operations for a period after the pandemic began.

But those using ART make up a small minority of pregnancies, Levine said, adding that even though the rate of decline was highest among older women, those in their early 30s accounted for three times as many missing births as those in their early 40s, since the younger age group accounts for a larger share of total births.

The other group that saw a significant decline in births was teens, for whom “separation from peers (likely) reduced opportunities for sexual encounters,” the report found.

By February 2021, the birthrate had bounced back to expected levels, and in June, the latest month included in the data, there was even a spike, suggesting that by September 2020 people were feeling more optimistic.

The rebound corresponded with a reduction of the unemployment rate from a high of 14.5 percent in April 2020 to 7.8 percent by September, and a reduction in daily cases and deaths before the winter spike later that year, the report said.

Economic hardships associated with the coronavirus pandemic have been shorter-lived than those associated with the Great Recession, Levine said, adding that government assistance was far more robust during the pandemic. Stimulus checks, increased unemployment insurance benefits and expansions to the child tax credit probably helped keep the birthrates from plummeting even further, he said.

“In the covid recession we basically used every weapon in our arsenal, and that seemed to have worked," he said. "To the extent that women have fewer children when times are tough, if we implement strategies to lessen the impact that would limit the reduction in births.”

However, he cautioned that any decline in births because of the pandemic should be viewed in the context of the greater long-term and continuing decline in birthrates underway before coronavirus hit.

The birthrate in America fell 4 percent in 2020, marking the biggest annual decrease in decades. About 3.6 million babies were born in the United States in 2020, compared with about 3.75 million in 2019. It was the lowest number of births since 1979 and the largest one-year drop in percentage terms since 1965, the year the baby boom ended. The United States now has about 700,000 fewer births annually than it did in 2007.

For Athanasiades, the advent of vaccines last spring helped her reconsider having another child, as did the prospect of her daughter getting inoculated (although vaccines for young children have ended up taking longer than anticipated). During the course of the pandemic, she also became closer with neighbors, forming a new support network that made it easier to imagine having a second child.

“I didn’t know if we were out of the woods, but it felt more optimistic,” she said. After getting vaccinated, she had her IUD removed; she is now seven months pregnant.