How Jason Aldean Supported Brother-in-Law Chuck Wicks and Wife Kasi During Infertility Journey

When country artist and radio personality Chuck Wicks and his wife, Kasi, learned last fall they were suffering from infertility, their difficult journey to pregnancy quickly became a family affair.

"That's been the best thing about this whole process," Chuck, 40, tells PEOPLE for this week's issue, out Friday. "A lot of people have to do this on their own and don't have a support system, so we're very blessed."

And of all the members of their large blended family, none have been more supportive than Kasi's beloved older brother, Jason Aldean, and his wife, Brittany.

"Their attitude was so positive," says Kasi, 36, who is due to deliver the Nashville, Tennessee-based couple's son in December. "They just helped us stay positive, as well."

The Aldeans' optimistic spirit, of course, was earned from their own successful experiences dealing with infertility. Jason, 43, and Brittany, who turns 33 on Friday, have been open about the fact that both of their children — daughter Navy Rome, 16 months, and son Memphis, 2½ — were conceived through in vitro fertilization (IVF).

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Avery Morstad Kasi and Chuck Wicks

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In the Aldeans' case, the cause of infertility was Brittany's endometriosis, abnormal tissue growth inside the uterus that can inhibit conception. For Chuck and Kasi, the issue was male infertility. Chuck's sperm count was never more than 15 when, normally, a single ejaculation contains 100 million sperm. The couple began pursuing the only available course of treatment: retrieving Chuck's few sperm for IVF.

The Aldeans' initial help arrived in the form of medical recommendations — "We had the same doctor and the same nurses," says Kasi — and then their encouragement continued throughout the process.

Perhaps the most crucial time arrived when Kasi's eggs were retrieved. The few sperm that Chuck had been producing for specimens were already frozen, and on this day, he produced a fresh specimen, which is considered more dependable. But its tiny number of sperm were listless and considered unusable.

Then the couple learned none of Chuck's frozen sperm had survived the thawing process — a not uncommon outcome, according to Dr. Peter Schlegel, a New York urologist and nationally recognized fertility expert.

Courtesy Chuck Wicks Kasi and Chuck Wicks

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In a last-ditch effort, the couple's medical team administered a stimulant to the fresh specimen, and two sperm came to life. One each was then injected directly into two eggs, and the next day, the couple learned one of the eggs had been successfully fertilized. Their joy was tempered, though, with the stress of waiting several days to see if this single embryo would grow.

"Even when we were, like, 'There's only one, we don't know if it's going to survive,' " says Kasi, "my brother was like, 'Oh, it's going to survive.' He never questioned it for one second."

Kasi's side of the family was well acquainted with the IVF procedure, not only because of the Aldeans' experience but also because one of Kasi's three daughters from her first marriage — Avery, now 9 — was conceived through IVF, which was necessary because of her then-husband's vasectomy. Chuck's family, however, knew little about IVF, and had to receive a quick education.

"It was funny because we would tell them things that were happening," Kasi recalls, "and I don't even think they knew what to ask."

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And yes, the couple says, there were probably a lot more conversations about sperm than they'd ever had before.

"One hundred percent," Kasi tells PEOPLE with a laugh. "Our family knows way too many details about us!"

The mother-to-be, who has a career as a pharmaceutical sales rep, says she also helped her daughter Avery understand the IVF process.

"We actually had conversations that I didn't realize we'd start having this early, where babies come from and how that works," Kasi recalls. "And it also was interesting because she started to realize that [IVF] is how she got here, too, so we had that conversation. It was a really big moment for our family."

Eric Ryan Anderson Makenzie, Avery and Madison Morstad with Chuck Wicks and their dogs

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As Kasi endured months of the daily hormone injections needed for an IVF pregnancy, Avery comforted and distracted her mother during the shots by holding her hand and singing to her. Kasi's two older daughters — Madison, 19, and Makenzie, 21 — also "have been there every step of the way," says their mom. (She adopted them after she married their father, whose first wife died from breast cancer.)

The whole family, Kasi adds, knows that having a baby boy is going "to be a different dynamic, for sure, and we're all excited about that" — and Chuck, of course, is thrilled about adding to his number in the household, and he says he has settled his wife's anxiety about raising a son: "I was so happy to tell her, 'Listen, boys' stuff — got you covered! I know all about it. I was a boy.' "

At the same time, Chuck also has been having a few trepidations about taking care of a baby. But once again, the Aldeans have come to the rescue.

"I get to be around Memphis and Navy a lot," Chuck reports, "and it's fun to watch how Kasi is with them. I'm really taking notice of what's happening, so I'm ready. Like, 'Okay, that's how they're changing the diaper. Okay, good, got that. This is how they feed them. Okay, got that.' I'm ready. I can't wait."

Eric Ryan Anderson Kasi and Chuck Wicks

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The dad-to-be does have a lot to keep him occupied between now and the December birth. He's currently in the final stages of signing a new recording contract, and after a six-year run as part of the team on NASH-FM's syndicated Ty Bentli Show, he's working on a podcast collaboration with broadcast personality Bobby Bones.

"I'm excited for the new chapter of my life," he says. "I'm open to everything. I've never wanted to be a one-dimensional artist. I've always liked to do a lot of different things."

And now, Chuck says, he's more motivated than ever to achieve. "I want my boy to grow up looking up to his daddy," he says. "I want to provide for him in every single way."

For more from Chuck Wicks, pick up this week's issue of PEOPLE, on newsstands Friday.