The 27-year-old "Lips Are Movin" singer spoke to TODAY on Wednesday about the challenges that now-3-month-old son Riley faced when he joined the world on Feb. 25.
"It was one of those horror stories where he didn't cry," Trainor said. "He didn't make noise when he came out. I was like, 'Why isn't he crying?' Then they told me he was having breathing issues. It was terrifying."
After he was born, Riley was taken to the hospital's NICU, where he used a feeding tube. Trainor recalled that not getting to bond with him right away was particularly difficult.
"I got to see him for one second before they took him away. That was probably the worst part," she said. "It was definitely a rough start. But we're so lucky we got to bring him home after five days."
Back in February, Trainor announced on Instagram that Riley arrived one week early at a healthy weight of 7 pounds and 8 ounces.
"This sweet baby boy's due date was today on Valentine's Day. We got to meet him Monday, Feb 8th!" the star wrote at the time. "We are SO IN LOVE [crying emoji]. Thank you @darylsabara for the best Valentine's gift ever! Welcome to the world Riley!"
In April, she gave offered more information about Riley's journey, sharing a video to TikTok showing him hooked up to tubes and monitors shortly after birth.
"We had a rocky start...but thanks to the amazing nurses, doctors, and pediatricians, Riley is a perfect, healthy and happy baby," she captioned the video.
In December 2020, Trainor – who tied the knot with 28-year-old "Spy Kids" franchise alum Sabara in December 2018 – revealed she had been diagnosed with gestational diabetes, a temporary condition that can lead to breathing difficulties in babies.