KYIV, Ukraine (AP) — As Vitalii Khroniuk lay facedown on the ground taking cover from Russian artillery fire, the Ukrainian soldier had just one regret: He had never had a child.

Aware that he could die at any moment, the 29-year-old decided to try cryopreservation — the process of freezing sperm or eggs that some Ukrainian soldiers are turning to as they face the possibility that they might never go home.

“It’s not scary to die, but it’s scary when you don’t leave anyone behind,” said Khroniuk, who had quickly joined the war effort, without a thought about his future, when Russia invaded Ukraine nearly a year ago.

During a vacation home in January, he and his partner went to a private clinic in Kyiv, IVMED, that is waiving the $55 cost of cryopreservation for soldiers. The clinic has had about 100 soldiers freeze sperm since the invasion, says its chief doctor, Halyna Strelko. Assisted conception services to get pregnant currently cost $800 to $3,500.

“We don’t know how else to help. We can only make children or help make them. We don’t have weapons, we can’t fight, but what we do is also important,” said Strelko, whose clinic had to close during the first months of the war as Kyiv was under attack but reopened after the Russian military retreated from the area.

When Khroniuk told his partner, Anna Sokurenko, 24, what he wanted to do, she initially was unsure.

“It was very painful to realize that there is a possibility that he will not return,” said Sokurenko, adding that it took her a night of reflection to agree.

She and Khroniuk spoke to The Associated Press while sitting at the clinic, where posters of smiling babies, including one that reads, “Your future is securely protected,” hang in the corridor. The clinic’s lab has its own backup power supply that kicks in during frequent outages from Russian missile strikes damaging the electric infrastructure.

Strelko, who has been in the fertility business since 1998, said the service she is offering soldiers is particularly important now, pointing to “a very aggressive part of this war with massive losses.”

Russian forces have been pushing their advance on the eastern city of Bakhmut with heavy shelling and attacks that are believed to have produced massive troop losses for both Ukraine and Russia. Neither side is saying how many have died.

Sokurenko and Khroniuk married a few days after their clinic visit, and he is now fighting in the Chernihiv region near the border. She believes that a chance to have a child, even after a partner is killed at war, could smooth the deep pain of loss.

“I think it’s a very important opportunity in the future if a woman loses her loved one,” she said. “I understand that it will be difficult to recover from this, but it will give the sense to continue to fight, to continue to live.”

Nataliia Kyrkach-Antonenko, 37, got pregnant while visiting her husband in a front-line town a few months before he was killed in battle. Her husband, Vitalii, came home to Kyiv for a short vacation 10 days before his November death and got to see an ultrasound of his unborn baby girl. He also visited a fertility clinic to freeze his sperm.

Kyrkach-Antonenko hopes to eventually have another child using that sperm. She said being able to have her late husband’s children “is an incredible support.”

“We have loved each other incredibly strong for 18 years,” she said.

She also sees cryopreservation as a fight for the country’s future.

“Their dads did everything possible to make this future happen. Now it is our turn, as women, to fight for the future of Ukraine as well, raising people with dignity. People who can continue to change the country for the better,” she said.

Another couple who went to the IVMED clinic in December, Oles and Iryna, asked that only their first names be used because of privacy concerns.

Oles is in the Donetsk region, where some cities were turned into hellscapes due to fierce battles over the past months, and sees cryopreservation as an assurance.

Iryna spends her nights alone in their apartment on the outskirts of Kyiv, tossing between anxiety for her husband as he fights on the most intensive and deadly part of the eastern frontline and the numerous visits to the clinic where she is trying to get pregnant.

“Yes, it is a difficult life, with worries, bombardment, with constant anxiety for relatives. But at the same time, it is what it is,” she says. “It’s better to be a parent now than to put it off until you can no longer have children.”

“Family is what will hold our country, and children are our future,” she said. “We fight for them.”