The expectant parents spend weeks deciding on their new baby’s name. Then the grandparents weigh in.

Rachel Templeton felt honored when her father-in-law invited her out to dinner on Long Island, just six weeks after the birth of her first child. Expecting a celebratory event, she dressed with care for what would be her first real postpartum outing.

The restaurant was lovely, but “the light banter quickly turned serious,” Templeton recalled. Her father-in-law announced that she and her husband should change the name they had carefully chosen for their son, Isaiah.

Growing up in Philadelphia, he explained, he had encountered anti-Semitic sneers and discrimination; now he feared that a biblical name would make his new grandson a target. To protect the child, the family should use his middle name instead.

Startled and hurt, Templeton coolly replied, “If I ever feel he’s being harmed by his name, I’ll consider it. But in exchange, I never want to hear about this again.” Isaiah is 9 now, and she and her father-in-law had not discussed the matter in all those years, until they told me the story.

But Templeton, 45, a radio reporter in San Juan, Puerto Rico, clearly hadn’t forgotten the conversation. And her father-in-law, who asked to remain anonymous, insisted, “I still agree with my original premise,” reasoning that “there was a lot of anti-Semitism when I grew up and there’s a lot now.”

Other parents remember tangling with grandparents over baby names, too. An accountant in suburban Phoenix, a newlywed when she met her husband’s maternal grandmother, warmed to her instantly and vowed to name her first daughter in the grandmother’s honor: Colleen. “We didn’t think there would be any drama,” she said.

Wrong. Her in-laws had divorced years before her marriage, and her father-in-law was upset that they wanted to name the baby after his ex-wife’s side of the family.

The new parents felt whipsawed, wanting to keep everyone happy while also defending their independence. “Telling someone what you can or can’t name your child is so controlling,” the accountant said. She told her husband, “I didn’t marry your dad.” After considerable back and forth, they went with Colleen.

What’s in a name? Maybe more than grandparents-to-be think or anticipate when their expectant children are kicking around the possibilities.

“Names are all about identity,” said Pamela Redmond, chief executive of the giant Nameberry baby-naming site and co-author of 10 books on baby names. “The name the parents choose is central to who the child is and will be, and grandparents feel very invested in that.”

Maybe grandparents want a family name carried on, or one that reflects their religious or ethnic identity. If their children have other ideas — these days, they often do — “the link to their ancestry is broken,” Redmond pointed out.

Plus, grandparents might have their own notions of appropriateness and a probably misguided sense that their grandchildren’s names reflect on them. So when their children creatively come up with Nevaeh (it’s “heaven,” backward) or use the city where the baby was conceived (like Nashua), they bridle.

“If you’re the conservative who named your kids Tom and Emily, and they’re naming their daughter Miles and their son Freedom, it’s like showing up at the country club with blue hair and tattoos,” Redmond said.

Being different is often the point, though. Young parents face a vastly wider assortment of choices than older generations ever considered. New parents may gravitate toward gender-neutral names, for instance. Older generations’ notions about playground taunts have become outdated when kids have such diverse names that a plain vanilla Linda or a mundane Mike may yearn for something more distinctive.

But that doesn’t prevent some grandparents from wading into the fray. Sometimes, since more spouses now keep their own names when they marry, differences arise not over the newcomer’s first name but the surname.

Mary Lou Ciolfi got an earful from her mother about her children’s last names. Ciolfi kept her name when she married in 1984, and she and her husband reflexively gave their son his father’s last name. Four years later, pregnant with a daughter, Ciolfi thought, “Why should he get all the names?” Her whole family is Italian and “very ethnic in our traditions.”

When she told her mother that her daughter would have her last name, “she was annoyed and angry with me and tried to talk me out of it,” said Ciolfi, 60, who teaches public health at the University of New England. “She said silly things like, my children wouldn’t know they were siblings. I was just rolling my eyes.”

As it happens, Ciolfi’s two sons (surnamed Vorhees) and her daughter (named Ciolfi) know perfectly well that they’re siblings. As for her late mother, “she was totally in love with all her grandchildren and moved past it.”

That tends to happen, said Sally Tannen, who has directed parenting workshops at the 92nd Street Y in Manhattan for nearly 20 years, and grandparenting workshops for four.

The discussions can get intense, said Tannen, whose youngest grandchildren are twins named Cedar and Shepard. “This is the first stage in grandparents’ realizing that this is not their kid and they don’t have control,” she continued. “They have to step back, and some are good at that and some are terrible.”

Sometimes, parents find face-saving solutions, like giving children middle names they will never use to placate one grandparent or another.

But clashes over names can backfire, Tannen pointed out, if they make new parents angry enough to withdraw.

Fortunately, as Ciolfi discovered, these conflicts tend to fade after the grandchildren actually arrive. “As soon as you’re pregnant, everyone has an opinion” about names, Tannen has observed. “Once there’s a baby, it would be pretty silly to hold onto that.”