Almost as soon as Eryn Yates made it through her first trimester of pregnancy last spring, she started shopping for her dream nursery.

But getting the items she wanted turned into a nightmare.

The crib that she had ordered from Crate & Barrel arrived within weeks, but the rocking chair from Pottery Barn Kids was back-ordered for months, and then lost somewhere in transit. The delivery of the dresser she was going to use as her changing table was repeatedly postponed until West Elm informed her that it would be delivered in late April or May 2022 — more than six months after her daughter’s birth.

“I definitely thought that we were ahead of the game since we started ordering everything so early,” said Ms. Yates, 27, who lives in Winter Garden, Fla., and works in health care. “I was wrong.”

Global supply chain disruptions wrought by the pandemic have snarled the delivery of items as varied as medical devices, toys and Grape-Nuts. But perhaps no delays have provoked more familial angst in the last two years than those for baby items.

Unlike many products that are ferried through the supply chain, things like cribs, car seats and strollers for newborns have an unforgiving deadline in the form of a due date. And some parents-to-be, either superstitious or simply dilatory, hesitate to purchase baby items far in advance. That puts them at odds with supply chain turmoil that has sometimes made it necessary to buy items weeks or months ahead of time.

“When there’s a human on the other side of it who’s coming into the world for the first time, it’s a different ballgame,” said Sylvana Ward Durrett, the chief executive and a founder of Maisonette, an online marketplace for baby and children products.

Demand is unlikely to let up. Even with a declining birthrate, there were more than 3.6 million births in the United States in 2020.

The result of the baby-supply upheaval — besides higher prices and an ever-bustling hand-me-down market — has been an injection of new stress and uncertainty into an already emotionally delicate time. Expectant parents are scrambling to get items before they bring their babies home, and retailers and manufacturers are racing to reassure them that their goods will come, and devising hasty solutions if they won’t. Message boards on sites for new parents teem with complaints over back orders and repeated shipment delays. Retailers have become accustomed to soothing anxious parents-to-be.

“These are pregnant women that are all having their babies,” said Lauren Logan, the owner of the Juvenile Shop, a family-run baby retailer in the Sherman Oaks neighborhood of Los Angeles. “They are hormonal, but they are pregnant — they want their stuff. I don’t blame them. I want their stuff for them.”

Lead times for furniture and other items, made in Asia, Europe and the United States, are “longer than they’ve ever been,” said Ms. Logan, who has worked at the Juvenile Shop since 1979. Some products that used to take eight to 10 weeks to arrive now take 18 to 20 weeks, with potential snags all along the supply chain.

To help new parents, Ms. Logan has lent out floor models and products from the store’s warehouse, a stopgap that has relieved some pressure but that has also cost her business money.

“We are giving out loaner furniture, loaner chairs, loaner car seats, whatever it takes,” she said. “If people are having their babies, they need something.”

Maisonette, which works with nearly 1,000 vendors, said the bulk of products facing delays had come out of Asia, along with Peru, where Pima cotton for baby apparel and pajamas is produced. Babylist, a registry site, said retailers were having a particularly hard time keeping hot branded items like the Doona stroller, Snoo bassinet, Keekaroo diaper changing pad and Elvie pump in stock.

Sellers point to numerous supply chain problems, including the availability of parts and shipping containers, backlogs at ports, a lack of truckers and even logistical challenges once items finally arrive at warehouses or distribution facilities.

Production of a continuously sold item typically took 45 to 60 days, and it then required 12 days to travel across the ocean to California, said Joe Shamie, president of Delta Children, a major family-run seller of cribs and children’s furniture carried at retailers including Walmart and Pottery Barn. Now it takes a couple of months just to transport the items to the United States.

The cost of freight to import products has also skyrocketed, from under $2,000 to $15,000 or $20,000 per container, which the company has largely absorbed so far, Mr. Shamie said. A typical container can fit about 300 cribs, he said.

“We’ve had situations where we have a hot product and are rushing to get things in — this is not what this is,” he said. “This is a case of the actual system being broken down.”

Those kinds of challenges have led some sellers to diversify their supply chains and focus on best-selling products.

Million Dollar Baby, whose brands include Babyletto and DaVinci, has increased the number of freight carriers and trucking companies it works with in an effort to dislodge the shipping backlog, said Teddy Fong, the chief executive. It has also made the Babyletto Hudson and Lolly cribs, among its most popular items, a manufacturing priority in Taiwan.

Still, roughly 35 percent of Million Dollar Baby’s items are out of stock at any point, though they typically become available again in two to three weeks, said Mr. Fong, whose parents founded the company in Los Angeles in 1990.

“It’s all sorts of these stories and seemingly new bottlenecks that pop up every week,” he said. “It’s very frustrating because there isn’t a clear line of sight in terms of what needs to be done to get us out of the situation.”

On the receiving end are customers who don’t need another source of anxiety. First-time parents often research heavily before selecting strollers, cribs, car seats and other wares. And out-of-stock items can crimp registries; Babylist says new parents often select 100 to 200 items.

After Gina Catallo-Kokoletsos, 33, and her husband finally agreed on a crib from Pottery Barn Kids, her father placed the order as a gift in July. Originally, the crib was supposed to ship in October, giving just enough time before the couple’s baby was due in November. But when Ms. Catallo-Kokoletsos checked in September, she saw that the shipment date had been pushed to January.

“I called them, and they were like, ‘Oh, yeah, it’s going to be delayed.’ And I said, ‘Well, my baby is due before that,’” said Ms. Catallo-Kokoletsos, who lives in Chico, Calif., and works at an animal shelter. She ended up canceling the order and choosing a crib from a small company she had never heard of. That crib arrived on time, but other items on her baby registry, including a rocking chair, went out of stock before she could get them.

“I knew none of it was the end of the world,” she said. “It just kind of gets frustrating after a while.”

Further complicating matters for some expectant parents are deeply ingrained beliefs about buying or receiving items before their babies are born.

Joelle Fox, 35, a naturopathic physician in Scottsdale, Ariz., who is expecting a baby boy in January, said she was wary of ordering anything in part because of a custom among many Jewish people of not having baby things in the house until the baby arrives.

“It’s kind of a tradition that women have done, and I was kind of following that,” she said, adding that she also wanted to research items carefully to make sure they were not harmful. But the supply chain issues compelled her to start buying some items for the nursery at the end of October, a decision that she said prompted “a lot of emotions.”

Even still, she said, the dresser she ordered from Wayfair is not supposed to ship until mid-January. “That has definitely put a bit of a damper on everything, because I can’t get the room completely set up,” she said.

At around 36 weeks pregnant, Ms. Yates in Florida, whose daughter was born in October, gave up on receiving the West Elm dresser and bought one from Ikea. She cut off its legs and replaced them with metal ones that matched the crib she had bought.

She had less luck with her Pottery Barn Kids chair, which she had ordered in June. After it failed to arrive, she felt so desperate that she emailed corporate customer service and copied the chief executive. By the time she was told in October that the chair had been lost, the color and fabric she wanted were no longer available. The company ended up sending her a loaner chair, in a different color, “so I at least had something in the room for me to use.”

Ms. Yates said that she was sympathetic to the companies’ struggles, but that the ordeal still had left her in tears.

“I was not a very emotional pregnant woman — I had a very short temper, rather than being a crier,” she said. “But when it came to the nursery, I cried a lot, because I had this picture of exactly what I wanted, and then it just felt like one thing after another.”