The Parent Trip: Melissa and Evan Rosenberg of Bala Cynwyd

THE PARENTS: Melissa Rosenberg, 27, and Evan Rosenberg, 29, of Bala Cynwyd
THE KIDS: Sara Penina, 2 ½; Noam David, born Aug. 31, 2016
THEIR SURPRISES WHEN SARA WAS BORN: Evan thought, "That's a sweet cry." Melissa, who had expected a bald baby, thought, "She has hair!"

Melissa and Evan were still scratching their mosquito bites, acquired during a five-day vacation in the Dominican Republic, when the World Health Organization declared Zika a global health emergency.

Their toddler, Sara, also had been bitten; she'd developed a fever and rash.

And - though they hadn't yet told relatives or friends - Melissa was eight weeks pregnant.

"We cried a lot. The thought of having a child with microcephaly was terrifying," she says. The couple, who are Orthodox Jews, consulted with doctors and rabbis; their advice was to amp up prenatal testing. So, although they generally favored a low-intervention approach, they opted for blood tests, amniocentesis, and frequent ultrasounds to check the baby's growth.

Every test came back negative. Still, it was a long, hot, scary summer. Labor came on slowly - weeks of intermittent contractions - and then fast, with a brisk trip to Lifecycle WomanCare in Bryn Mawr. A classmate who had just graduated with Melissa from the University of Pennsylvania's midwifery program caught the baby; another classmate held her hand. And Evan (who goes by his Hebrew name, Etan, with family and in their religious community) knew exactly where to apply vigorous back pressure to counteract the pain.

Then their fears dissolved: Here was their son, an infant with thick blond hair, named in honor of Darche Noam, the Israeli seminary where Melissa learned to be an observant Jew.

Noam means "pleasant." His middle name, David, was in honor of his paternal great-grandfather, a man who crafted magic tricks from household objects to mesmerize Evan and his brothers. "We were so thankful to God that everything was fine with this baby," Melissa says.

There was never a question about whether they wanted children. Religious Jews consider it a mitzvah - a blessing and an obligation - to have at least two. And the same fascination that prodded Melissa to study midwifery made her yearn to experience pregnancy and childbirth.

They met as undergraduates - she was at Penn, he was at Drexel - and dated in modern Orthodox fashion: that is, walks on the Sabbath, kosher meals at Hillel, dinners (though she never stayed the night) with his family in Northeast Philadelphia.

He accidentally scooted a chair onto her foot during their first lunch together; he apologized profusely and fetched her some ice. She invited him to meet her pet hamsters, Mizu and Rayu. When it was too snowy to walk outside, they climbed the 24 flights of stairs in Melissa's high-rise dorm, talking the whole time. They played pool and foosball and went to the movies.

"We took dating very seriously from the get-go," Evan says. Melissa's dream was to receive a marriage proposal in a hot-air balloon, but Evan felt stymied by the logistics of arranging that.

Instead, he built a non-floating facsimile: a refrigerator box tricked out with lace and wrapping paper, with a door cut in the side, tethered to 50 helium balloons. He and his brothers drove the contraption to Pennypack Park and hid it in the woods. Then, on a walk with Melissa, he proffered a bouquet of flowers, a framed collage of ticket stubs from all their outings . . . then led her, blindfolded, to the balloon. He knelt on a purple tarp. She said yes.

Their wedding was according to Orthodox tradition: They didn't see one another for a week before the ceremony, a ritual followed by a raucous cabaret of friends - men on one side, women on the other - doing impromptu backflips, magic tricks, and, finally, hoisting Melissa and Evan in chairs so they could dance together in midair, each clutching one corner of a white napkin.

Shortly after their marriage, an unplanned pregnancy ended in miscarriage at nine weeks. Almost two years later, after graduating from Penn with a nursing degree and landing a job at Children's Hospital of Pennsylvania, Melissa ducked into the bathroom at work - it was Father's Day 2013 - and emerged with a positive pregnancy test.

Though they observed the Jewish custom - a superstition, really, against inviting the "evil eye" - of not buying new items for the baby until after the birth, they did need to childproof their home, removing the sharp-cornered coffee table topped with a glass chess set and shifting exercise equipment to make way for a nursery.

Melissa studied HypnoBirthing techniques and obsessively reread Ina May Gaskin's guide to natural childbirth, which left her determined to labor without medication. And she did: from the moment her contractions began, just after the end of the Sabbath, to the final 23 minutes of pushing at the birth center. The couple named their daughter for Melissa's mother, who died when Melissa was in high school; her middle name, Penina, means "pearl."

Now that they have two - one in the throes of potty training, one not yet crawling - Evan's devised a musical mantra, "Ev-ery-thing takes for-ever with child-ren," that he sings as he's bribing Sara to get ready in the morning ("One chocolate chip. OK. Two.") or struggling to get both kids out the door for a trip to the zoo.

"You're ready to go, and someone poops," Melissa says. "Or one needs a nap. You think: Do we have food? Do we need more diapers in the diaper bag?"

Still, they plan an outing every available Sunday: Longwood Gardens, or apple-picking, or a picnic in a Center City park. "I always thought I'd want to dump the kids with my parents and go rock-climbing with Melissa," Evan says. "But we want to take advantage of the time we have with them."

Even if it's 11 a.m. before they make it to the car, even if Sara has a tantrum or coughs too close to her baby brother, even if parenting two is an exercise in "divide-and-conquer," there's a sense of fleeting sweetness to it all. "My kids will only be this stage once," Melissa says. "We'll never get this day back."