THE PARENTS: Chrissy Hower, 37, and Sean Hower, 42, of Wilmington

THE CHILD: Ryan Thomas, born February 25, 2017

HOW THEY NAMED THEIR SON: Crowd-sourcing at one of their baby showers yielded a list of 30; Chrissy narrowed the field to "Ryan" or "David," then jettisoned the latter because it was the name of an ex-boyfriend.

Chrissy Hower crossed the finish line of the Delaware Half-Marathon in 2015 and burst into tears.

Earlier that spring, she'd been pregnant—a successful implantation of a genetically sound embryo produced during her first IVF cycle, following a series of failed intra-uterine inseminations the year before.

She'd endured daily intramuscular injections and medication-juiced mood swings. She knew the numbers: 24 eggs retrieved, 16 embryos fertilized, three that had all their chromosomes in order. They froze two and transferred one. They heard a heartbeat. And then, they didn't.

Chrissy used Facebook to share her anguish. "There's a big stigma attached to miscarriage," she says. "I wanted people to know." She took a leave of absence from her job as a Weight Watchers instructor; sometimes she phoned her husband, sobbing, in the middle of the day. Sean tried to reassure her: No matter what happens, he told her, we'll always be together.

That wasn't always the case for this couple, who began dating when Chrissy was a sophomore and Sean was about to graduate from Indiana University of Pennsylvania. She didn't want a long-distance relationship. "I referred to him as 'the one who got away,'" she says.

Two years later, they reconnected; Sean invited Chrissy to be his date—as a friend, mind you—at a fraternity brother's wedding in Pittsburgh. "I never thought we would get back together," he says, "but when we saw each other…I realized there was still something going on between us."

Chrissy felt that same click. "When I first saw him at the bus station, I knew I was going to marry him."

They wed at the courthouse in Kennett Square in 2004; Chrissy remembers how Sean kept his suit jacket on, for the sake of formal pictures, as they strolled through Longwood Gardens on that glimmering July day.

After Chrissy turned 30, their conversation about children shifted from "not yet" to "let's see what happens." But after more than two years of nothing happening, they reluctantly sought counsel from a fertility specialist. Sean hated the idea of asking for help; Chrissy was afraid to learn what might be wrong.

The answer—endometriosis—actually came as a relief, an explanation for years of painful periods. When the doctor advised that IUIs might offer them a 10 percent chance of becoming pregnant, Chrissy thought, "Ten percent for other people; we're going to beat that."

But after three failures, they were ready to up the ante with IVF. After that tearful Mother's Day run, they opted to try twice more, with the two frozen embryos from the first cycle. They were implanted—one at a time—but didn't grow.

When the coverage for fertility treatment expanded at the company where Sean works as an accountant, they decided to try another IVF cycle. This time, there were just eight eggs, yielding three fertilized, genetically intact embryos.

Then the phone call came. Positive—meaning pregnancy. "I was ecstatic, but terrified at the same time," Chrissy says. "I had that cautious optimism: just because everything's OK with the chromosomes, that doesn't mean…every ultrasound was holding our breath until we saw the heartbeat."

She planned to wait before sharing the news, but when a co-worker arrived one morning drenched in perfume, and Chrissy bolted to the bathroom, her secret was out. Morning sickness and food aversions—she couldn't bear the smell of ground meat or chicken—meant a diet of "every kind of cracker imaginable."

Her anxiety hovered at red-alert levels, even as each ultrasound reassured them of the baby's growth. Sean knew a co-worker whose baby died two days before delivery; a woman in Chrissy's online support group had given birth to a stillborn infant. "I thought there might be a complication and this baby might not survive, that all of a sudden he could leave."

Chrissy's contractions started on a Friday night; after hours of labor at Christiana Hospital and the relief of an epidural, she started to push. "He was in the birth canal for four hours," she says. "I've done marathons and ultra-marathons. This was a whole different level of pain."

Finally, he was there: a 7-pound, 4-ounce infant on her chest; a wave of love and relief and doubt and guilt. "I know so many people who are still struggling and waiting to have babies," Chrissy says. "I had mine, but what about these other women?"

Breastfeeding was anguish. Sometimes Ryan latched, and sometimes he didn't; at 10 days, he refused to nurse. Chrissy tried to pump—two hours a day on the machine yielded a scant three ounces of milk—and finally, with a nod from her lactation consultant, she switched to formula.

Sean, meantime, was learning to decode their son's cries. "It took a while to decipher which is for a dirty diaper, which is food, which is gas, which is 'I need attention.'"

And Chrissy's emotions kept zigzagging. "When I was going through extreme anxiety the first couple of weeks, I thought, 'I should be happy; I should be thrilled. Why am I crying? This is what I've wanted for so long, and now I have him, and I'm a mess.'" A friend, pregnant with her third child, offered sage counsel: It doesn't matter how the baby got here; there will be great days and not-so-great days. Get used to it.

They're figuring it out: how one person can wrangle a baby and several bags of groceries from the car to their third-floor condo (bring the kid up first, put him in the bassinet and pray he doesn't start screaming before the frozen items are tucked away); how to juggle parenting and self-care (get a friend to watch Ryan while Chrissy and Sean have concurrent dentist appointments—almost like a date!).

And then there's the clean-diaper dance Sean invented: he sings to Ryan, wiggles the baby's arms and legs, does his own goofy, improvisational riff. He smiles. His son smiles back.