(CNN) -- A Texas couple married Tuesday in the neonatal intensive-care unit with their prematurely born son serving as ring bearer.

Justin Nelson and Kristi Warriner wed Tuesday in the NICU of Cook Children's Hospital in Fort Worth, where baby JJ has been since September. He was born 15 weeks early on September 2; his twin, Colt Austin, died in utero.

Dressed in a tuxedo onesie, JJ slept through most of the ceremony. He's being monitored for chronic lung disease.

"He has been struggling but has made great improvements," Warriner told CNN. "We still grieve but keep strong for JJ."

The couple postponed their wedding plans when Warriner became a high risk pregnancy because of twin-to-twin transfusion syndrome, a rare condition that occurs in identical twins who share a placenta. Warriner went to the emergency room on August 31 and discovered baby Colt had passed away. She started having contractions on September 1, and JJ, which stands for Justin Jr., arrived the next day.

With the help of Cook Children's staff, the couple wed in JJ's room, surrounded by family and their 8-year-old daughter, and invited local media to witness the event.

"Our mission behind sharing our story was to let those that have been there, are there or unfortunately could one day be there [know] that they are not alone."

Fort Worth Star-Telegram reporter Susan Schrock was on hand to capture the ceremony. The bride's "something blue" was her NICU visitor's wristband.

WFAA reporter Jason Wheeler also live-tweeted the #nicuwedding.

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