“The Little Couple” star Dr. Jen Arnold has revealed she has a rare form of cancer, a diagnosis that began with a non-viable pregnancy.

Arnold, 39, and her husband Bill Klein, 39, spoke to PEOPLE magazine about the neonatologist’s health struggles. They couple confirmed Arnold was diagnosed with stage 3 choriocarcinoma. She learned of her diagnosis soon after she found out she was pregnant in September, but the embryo had no heartbeat.

"The one time I get pregnant, I get cancer,” Arnold told the magazine.

"There are moments I feel just terrible," Arnold explained. "I can't believe it is happening. Other times, I feel like this is just a bump in the road."

The couple has two adopted children together, a son and daughter. Their son, 3-year-old Will, was brought home from China, while 2-year-old Zoey was adopted from India. During the couple’s trip to India this year, Arnold reportedly began bleeding.

"My initial thoughts were all about Zoey," Arnold told PEOPLE. "But then the bleeding got worse and I was feeling light-headed. It was a hard decision, but I had to go home."

Arnold contacted her OBGYN back in Houston, Texas and decided it was best for her to return to the United States. Her doctors tried chemotherapy, but the cancer didn’t respond. The doctors told the mother it would be best to perform a hysterectomy. Arnold has decided to share her cancer struggle with viewers of “The Little People”.

"We wanted to avoid surgery in her case because of her shortened airway and the difficulties she has had in the past with surgeries," Dr. Concepcion R. Diaz-Arrastia, director of gynecology oncology at Baylor College of Medicine, who is treating Arnold, explained to PEOPLE. "But we felt we had no choice. The disease was not responding to chemotherapy. We had to do this in order to save her life."