A Connecticut man who killed his seven-month-old son when he threw the boy from a 90ft bridge has been jailed for 70 years.

A judge imposed the maximum prison time on Tony Moreno, 23, who was convicted by a jury in February of murder and risk of injury to a minor.

"The utter depravity of the crime, a father killing his infant son, speaks for itself," Middletown Superior Court Judge Elpedio Vitale said.

Police said Moreno threw his son, Aaden, off the Arrigoni Bridge over the Connecticut River in Middletown in July 2015.

He then jumped off himself and was seriously wounded, but survived.

He testified during his trial that he accidentally dropped the boy and did not intend to harm him, despite having confessed to police that he threw the baby from the bridge.

Court records show Moreno exchanged angry text messages with the infant's mother in the minutes before he jumped. She frantically pleaded with him to not hurt the boy.

"Enjoy your new life without us," Moreno wrote. "He's dead. Soon I will be too."

Moreno's relationship with the boy's mother had become strained in the months leading up to Aaden's death, according to court documents. She refused his marriage proposal, and a custody dispute was settled just days before the bridge incident.

Police responded to the incident after Moreno's mother called 911 to report that her son had called her from the bridge with Aaden and said he was going to jump.

After officers arrived, they saw Moreno jump and found an empty baby stroller, but did not see the infant. Aaden's body was found two days later several miles downstream after an extensive search involving dive teams and helicopters.

Moreno's lawyer, Norman Pattis, told the judge that Moreno should be sentenced to the minimum mandatory 25 years in prison, saying Aaden's death was an accident. Mr Pattis said Moreno accepts responsibility for the boy's death and had been willing to plead guilty to the lesser crime of manslaughter.

"Tony told you what happened," Mr Pattis said. "The jury disregarded it. Aaden slipped from his grasp."

Aaden's mother, Adrianne Oyola, said she has tried to forgive Moreno, but cannot.

"Every time I wake up, I pray the nightmare will be over and my son will be in my arms," Ms Oyola said during the sentencing. "I won't see my son grow up. You took my whole world in front of me. You took my life."

After the court hearing, Moreno's mother, Denise Moreno, said: "This monster he's being portrayed as is not the person I gave birth to or loved."

AP