"This was kind of a wake-up call for people," says Dr. Paul Kastell, an obstetrician and professor at Long Island College Hospital in New York City. "They saw the towers burning. And when they got home they said, 'You know, it's never going to be the right time. We should start now."'
New York, which took the biggest hit in the terrorist attacks, is expected to be the boom's epicenter.
Kastell says that, beginning in mid-June, deliveries in his own Brooklyn practice will increase 20 to 25 percent compared with last summer. Dr. Jacques Moritz at St. Luke's-Roosevelt Hospital in Manhattan anticipates a 15 percent increase. And St. Vincent's Hospital, not far from ground zero, is also preparing for a summer boom, though it hasn't attached a percentage to it.
Elsewhere, some delivery room staffs around the country are also bracing themselves.
That includes Baylor University Medical Center in Dallas, where summer deliveries will include some of the hospital's own staff. Five nurses in Baylor's labor-and-delivery department are pregnant and due in July and August. Spokeswoman Kathryn Goldstein jokingly suggested the department adopt a new motto: "Don't drink the water."
And at least one celebrity will be among the proud parents. During a recent interview with Oprah Winfrey, comedian Chris Rock said Sept. 11 prompted him and his wife to conceive.
Elsewhere, Julia Beck Bromberg, husband Neil Bromberg and 3-year-old daughter Lila are preparing for an addition to their Bethesda, Md., home in July.
"If we had begun to take each other and our child for granted, this ended on that day," says Beck Bromberg, who is expecting a son.
She says the attacks hit home largely because her husband, an attorney, works two blocks from the White House. New information suggests that might have been the intended target of the hijacked plane that crashed in Pennsylvania.
At this point, evidence of an overall jump in post-Sept. 11 pregnancies — even for the New York metropolitan area — is anecdotal. That's because it takes demographers weeks or even months to collect and tally official birth data.
There are, however, signs that a boom is coming, says Beck Bromberg, who runs a business called Forty Weeks, a wholesaler for products for babies and new mothers. Her company's sales to such retailers as Babiesrus.com are up more than 75 percent.
And in Miami, the Stork Avenue birth announcement company has added staff because catalog requests indicate that business could quadruple this summer.
When asked why they want to have a child in such turbulent times, many new parents cite a need for togetherness, healing and even patriotism.
"Maybe our child can help in some small way to make the world a better place," says Missy Acosta, who is due in July and lives in Mt. Juliet, Tenn., just outside Nashville.
Christopher Coyne, of Houston, says he and wife Trish conceived a daughter while on a brief honeymoon in Manhattan, one month after planes hit the World Trade Center.
They've decided to name her Nicole Yvette Coyne — initials "NYC."
But some experts say Sept. 11 isn't the only reason more couples are expecting.
While they're planning for an increase this summer compared with last, births were already up 6 percent in April at Women & Infants Hospital of Rhode Island in Providence. And Bassett Healthcare in upstate New York says a mini baby boom happened at its hospitals in the first quarter of this year.
Some suspect that means couples decided to place parenthood above fears about a shaky job market and faltering economy, not terrorism.
Even New Yorker Lisa Detwiler says the terrorist attacks she could see from her Brooklyn home did not prompt her to get pregnant, though they did have an effect.
She and husband Bill had been trying to conceive a third child for almost a year — and were finally successful after being cooped up in their home for days after Sept. 11 (they were unable to work in Manhattan).
"You're so happy that you're safe in bed and your husband is alive," she says.
Detwiler hopes the peaceful sound of the name they've chosen — Grace — will be a good omen, even as terrorist threats persist.
Of the name, she says: "Hopefully, that'll be an indication of the year to come."