When the personal shopper Negar Alaya’s son River Declan Bear was two months old in July 2022, she began looking for a piece of jewelry to commemorate his birth.

“I wanted something a little magical, a little mystical, an heirloom that was playful but not silly,” Ms. Alaya, 48, said by phone from her home in Los Gatos, Calif. While scrolling Instagram, she discovered the work of the London-based jewelry designer Cece Fein-Hughes, whose bespoke designs feature whimsical enamel illustrations.

So she messaged Ms. Fein-Hughes to discuss what Ms. Alaya described as “a push present to myself,” using a term that refers to a gift for a woman who gives birth. Five months later, the resulting $4,900, 18-karat yellow gold ring featured a champlevé bear sitting on a river of sapphires, beneath an emerald (River’s birthstone) and three diamonds to represent his mother, father and sister. Ms. Alaya later commissioned a $5,000 18-karat gold ring with an enamel illustration of a unicorn and a mermaid, chosen by her daughter Rooney, now 7.

Ms. Alaya is not alone among mothers seeking jewelry to celebrate their children. Such bespoke designs comprised more than 50 percent of Ms. Fein-Hughes’s 1 million pounds ($1.21 million) in revenue for 2022, the designer said by phone from her home in West London. The majority of her sales are initiated via Instagram, Ms. Fein-Hughes said, at prices ranging from £2,500 for a small 18-karat gold pendant to £15,000 for an oversize signet ring with miniature enamel paintings.

Well-known women including Kim Kardashian, Rihanna, Meghan Markle and Catherine, Princess of Wales, have all worn personalized jewelry that signifies their children.

There is no shortage of brands offering parents personalized designs featuring initials, names, dates, birthstones, fingerprints or children’s handwriting.

“Research is clear that millennials love customization — we love feeling like a mass-marketed product is unique to us and our identity,” Laura Snelgrove, the Montreal-based editor of the Fashion Studies Journal, wrote in an email. Social media, she wrote, had helped to shape a culture where “kids are almost worshiped, but mothers feel a need to stake a claim for their own identities too, resulting in wearing something that declares them to be ‘so-and-so’s mama’.”

Indeed, brands such as Lauren Rubinski, Jennifer Meyer, Yvonne Léon, Diane Kordas, Noa, Otiumberg and Roxanne First all produce jewelry bearing the word Mama.

And Phoebe Philo, the former creative director of Céline, released the long-awaited first collection of her new namesake line last month, including a circlet necklace spelling out Mum over and over in 23-karat-gold-plated sterling silver for £3,200, or $5,000 in the United States. The collection also included the necklace in sterling silver and a bracelet in gold-plated silver.

Although jewelers do sell designs bearing the word Mother, Mom, Mommy or Mum, Mama seems to be ubiquitous. Ms. Snelgrove attributed it to millennials waiting longer to start families, making them more likely to be raising small children into older ages. “So overall we have babies and little kids who still call us ‘Mama’,” she said. “‘Mama’ is the new identity we’re in the process of integrating.”

Juliet Hutton-Squire, co-founder and head of strategy at the global jewelry consultancy Adorn, said by phone that she viewed personalized baby-centric purchases as “separate to a push present,” which she said was traditionally “a gemstone ring, worn alongside a wedding and engagement ring.” She said that the market for motherhood-related jewelry had grown because “women are buying more jewelry for themselves in general to mark their own occasions, which they layer up to tell their personal story.”

Marking motherhood with precious jewels was especially popular in the 18th and 19th centuries, the jewelry historian Joanna Hardy said by phone from London. Queen Victoria’s collection, Ms. Hardy said, included jewelry set with the baby teeth of her youngest child, Princess Beatrice, and a charm bracelet with nine enameled lockets containing the hair of her children.

Jewelry remains “a visible reminder of the unique relationship between mother and child,” Dr. Carolyn Mair, a London-based cognitive psychologist and fashion business consultant, wrote in an email. Such merchandise, she said, “is a way for mothers to explicitly express and celebrate their role, and reinforce their sense of identity and belonging within the motherhood community.”

The often-isolating experience of new motherhood in Western culture also plays into the trend, Ms. Snelgrove wrote. “Some of this mom-identity-proclaiming fashion could be read as a cry for connection. If you’re expected to be performing as a professional while your heart is elsewhere, the desire to keep the kids close via one of these pieces is understandable.”

While initials are popular for first-time mothers, other women prefer more discreet markers of motherhood.

“When I first gave birth to two little people it felt like a huge feat, so wearing their initials around my neck was a celebration of them but also me as a mother,” said Alexandra Zagalsky, 47, a London-based freelance writer with two teenage children. But now, she said by phone, “I’ve moved away from wearing their initials toward more private, talismanic symbols of being a mother, because I feel like I don’t need to announce it anymore.”

Ms. Zagalsky now wears a Georg Jensen silver Offspring pendant, a gift from her own godmother, and designed by the Los Angeles-based Jacqueline Rabun to symbolize the mother-child bond.

She has also paid £790 at auction for a vintage Elsa Peretti for Tiffany pendant with three hearts of white, yellow and rose gold to represent her family. “As a single mum it felt important that I’m included, too,” she said.

Roxanne Rajcoomar-Hadden, a London-based jewelry designer, said, “When you have your first baby you probably want a name or initial.” But her customers are more likely to commission more complex pieces after their second or third child, “when you’ve grown into a different person: the mother of a family.”

Her bespoke gold designs, ranging from £3,000 to £10,000, include diamond and colored gemstone stick-figure representations of clients’ children and more abstract symbols that mark “the difficult transition from being an established woman with a career and identity to becoming a mother,” often reusing heirloom stones or gold melted down from pieces that belonged to a client’s mother.

Ms. Rajcoomar-Hadden also created Matrescence, a collection of pieces priced from £500 to £5,000 to mark what she called her own “motherhood journey.” The term matrescence was coined in the 1970s by the American anthropologist Dana Raphael to refer to the process of becoming a mother. “Some people say it takes seven to 10 years to get comfortable with the transition,” Ms. Rajcoomar-Hadden said.

The Matrescence range includes the £500 School Run earrings made from recycled household plastics strung from colorful, repurposed gemstones and the £5,000 Zigi ring, named after Ms. Rajcoomar-Hadden’s daughter and featuring an asymmetric halo of colored diamonds to represent the “unpredictable” nature of motherhood.

“To me jewelry is like therapy, and my designs represent the ups and downs of life,” she said.