The Parent Trip: Alisha Glennon and Jeffrey Stacey of Mount Airy

THE PARENTS: Alisha Glennon, 33, and Jeffrey Stacey, 33, of Mount Airy

THE KIDS: Evie Ryan, 6; August Patrick, 4; Bowie Glennon, 2; Shepard Theo, born December 14, 2017

REACTIONS TO THEIR FOURTH PREGNANCY: When Alisha told her family over Easter weekend, she and her sister laughed so hard the noise beckoned their mother to the bedroom. "My family was more shocked with No. 4 than with No. 1," she says.

There were two lines on the drugstore test stick, but the second was barely legible. Alisha threaded her way through cardboard boxes — they'd just moved to the apartment in Northern Liberties — and showed the inconclusive test to Jeffrey.

Then they went shopping. "I remember walking around Lowe's, thinking: Am I pregnant?" Alisha recalls. The next day, she tried again; this time, the line was definitively darker.

They wanted children. They even knew how many: four, a number they named every time Alisha's grandfather asked. Still, they felt jolted. "I remember sitting there, awake in that apartment, contemplating my future: Are we ready for this?" Jeffrey remembers.

The pair adventured well together, from their first date in their freshman year of college — Jeffrey drove a pal's '67 Mustang to a drive-in where the waitresses wore roller skates — to a junior-year study abroad program in Australia. They went skydiving, took a bridge hike, got lost in Sydney.

After graduation, Jeffrey was accepted to law school at Drexel University. Settling in Philadelphia, where Alisha was raised, meant they'd have a safety net of extended family.

Those years — Alisha calls them "adult-ing" — were all about work (for her, at a nonprofit focused on free speech) and study (for him), threaded with raising two Boston terriers, Murphy and Millie, making friends, and exploring the city's alleyways and pocket parks.

It was in one of those narrow, brick-paved lanes, on Labor Day weekend 2008, that Jeffrey knelt and recited an original poem about their relationship. Later, they had a celebratory picnic with friends and family.

What both savor about their wedding is the offbeat location — the Mütter Museum, with its jarred medical oddities — and the moments just after the ceremony, when the two were alone in a little room, sharing champagne. "We did it," Jeffrey recalls thinking. "We can just enjoy it now."

Though they had some questions about parenthood — Did they have enough money? Were they too young? — they also didn't know enough to be deeply anxious. "We didn't really have any friends with kids," Jeffrey says. "We were flying blind, in a way."

Alisha did know that she wanted a home birth, with a midwife, and meeting a local woman who had opted for the same plan confirmed her decision. Any doubts of Jeffrey's vanished when he asked the midwife how many home births she had assisted. "She said she'd stopped counting after 1,000."

The two did their homework; she watched birth videos while he pored over a book, The Birth Partner, on his daily train commute. Alisha woke up on a Saturday in January feeling as though labor might start soon. By dinnertime, a sushi meal with her parents, grandparents, and sister, she was having contractions. "At one point, I closed my eyes, and my grandma said, 'Oh, you're in labor.' "

The next afternoon, Alisha was in the bathroom when a trio of hard contractions hit. Her water broke. She wanted to push. Jeffrey abandoned his task of filling the birth tub with water to phone Alisha's parents, the doula, and the midwife, who lived 45 minutes away.

"Alisha's parents walk into the house, come upstairs, and see this tub that is about to overflow. In the other room, there's their daughter, without any medical professional, and me caught in the middle of all this," Jeffrey recalls. The midwife screeched onto their block in time to race to the bedroom, hug Alisha, and say, "You're doing great. This is it." A minute later, Evie was in her hands.

"Every single time we've been lucky enough to do that," Alisha says, "it's the same kind of feeling: Wow, what just happened? There's a new life in this room that wasn't here a minute ago."

The first night, they were euphoric. The second, exhausted. The third night, Evie wailed inconsolably for hours. "I remember looking at Jeffrey and saying, 'What were we thinking? How are we going to survive?' Then the baby blues passed, my milk came in, and we started to settle into being a family."

Four remained their magic number. Alisha was pregnant at Evie's first birthday party and gave birth to August after an intense two-hour labor at home. Bowie came after a textbook labor: contractions coming closer and closer together, enough time for the midwife to arrive. It's the only birth they managed to catch on videotape.

Bowie was an easy baby, but they were in the midst of moving again; their days spilled with work and scheduling, pre-K forms, and child care arrangements. Were they sure they wanted another?

"We weren't as quick to say, 'Let's do it again,' " Alisha says. "But in the back of our minds, we knew it was going to happen." The fourth pregnancy and Shepard's birth felt different, charged with the bittersweet knowledge that she would not be doing this again. "I knew this high would be the last birth-high; the latch would be the last birth-latch," Alisha says.

They've created email addresses for all four children, for messages to be read when they're older: "Dear Evie, you started Girl Scouts today … Dear Baby Shepard, you rolled over for the first time." In a decade — perhaps even in a month, Alisha knows — those details will float from memory.

Meantime, tumult is their norm: Alisha pumping milk in an Amtrak train bathroom while texting the au pair and wondering whether Evie needs to practice her sight words, whether August feels lost in the midst of his siblings. Or the night when Bowie stripped naked and colored himself all over with blue marker because, he insisted, "Bears are blue."

During a March storm, their power went out. No computers, no TV. The older kids buzzed around, delighted by an at-home adventure with flashlights. Jeffrey and Alisha cuddled Shepard in the flicker of candles. "These are our people, that we made," she remembers thinking. "Everything's going to be OK." It was almost a letdown when the lights snapped on.