Complications from a heart-valve defect left Danielle Dayton with a couple mortifying options when she became pregnant last year: Undergo open heart surgery, which could be fatal to her baby, or press on with pregnancy even though her heart probably couldn't keep up.

Fortunately, there was a third option, though doctors at Abbott Northwestern Hospital in Minneapolis believed it had been tried only once before in the United States. They proposed implanting a mechanical aortic valve in her heart so it could adequately pump blood to her body and to her baby.

"She was so symptomatic with a valve that was not going to potentially allow a safe outcome, either for mother or baby," said Dr. William Wagner, a maternal-fetal critical care specialist who handled Dayton's prenatal care.

Known as a transaortic valve replacement (TAVR), the procedure pushes back and replaces the defective aortic valve, which regulates blood flow out of the heart. Because the replacement has a limited life, the procedure is usually reserved for older adults or others too frail to survive corrective open heart surgery.

Dayton is just 28. The main risk of the procedure during pregnancy was that the valve replacement wouldn't work and doctors would have to switch to the open surgery that would jeopardize her baby. Doctors suggested an abortion — which could have prevented the immediate need for a cardiac procedure — but Dayton and her husband refused.

Something had to be done. At her 16th week of pregnancy, Dayton's heart was pumping 25 percent harder to keep up with the demands of her body and her baby. It left her dizzy and breathless. Before long, her cardiac output would surge 50 percent above normal.

"The decision wasn't easy." Dayton said. "However, it had to be made quickly."

Doctors first tried an angioplasty to push open her aortic valve. It backfired. The valve opened too wide, allowing blood to backflow into her heart. Dayton then consented to the valve replacement, which took place last August.

Proof of success came Jan. 24 when she safely delivered a healthy baby boy, Jaxon.

"He is 'talking' a lot and always very smiley," Dayton said. "He's got a big noggin!"

Dayton had known about her condition since childhood, but it hadn't been severe enough to disrupt family planning. Symptoms emerged after pregnancy.

Open heart surgery was always in her future, but the TAVR procedure bought her time, and a successful pregnancy, until surgery is needed.

"The guess at this point is it may be good for up to five years," Dayton said. "I didn't care that it was temporary … The reason for me to do the TAVR was strictly to keep our baby. Some may say that's crazy, but that's the decision my husband and I agreed on."

Jeremy Olson • 612-673-7744