A woman carries a sign to show support for the three murdered children of Lindsay Clancy during the Clancy's murder trial at Plymouth Superior Court in Plymouth, Massachusetts

The defense for Lindsay Clancy, the US mother accused of murdering her three children, on Thursday accused a single holdout juror of blocking a verdict in the high-profile trial.

Clancy, 36, does not deny strangling Cora, five, Dawson, three, and Callan, eight months, but claims she was suffering from postpartum psychosis -- excusing her from criminal responsibility.

Her five-week trial, which was televised and featured more than 80 witnesses, has sparked debate in the United States over maternal mental health.

Kevin Reddington, Clancy's main lawyer, told a Massachusetts court Thursday that there is "one juror who refuses to listen to the law that you've given him or her on reasonable doubt."