Mr Gibson-Watt told the inquest jury on November 13 his wife suffered what was described as a panic attack at home and began to crawl around her bed on all fours shouting her daughter was unsafe.
Giving evidence Mr Gibson-Watt said: "Neither Alice or I were at all aware of postpartum psychosis.
"What happened that first night was deeply traumatic and wholly unlike my dear wife Alice.
"After some 48 hours of her arrival at Lakeside Mental health unit, I was somewhat relieved she was in the right place to start receiving treatment.
"How wrong that turned out to be."
Concluding his short statement he said: "She was enthralled by motherhood. One day I will tell our daughter more about her wonderful mother.
"I just hope now finally we get as close as possible to the truth of her passing."
Alice Gibson-Watt worked for Sotheby's and appeared as an expert on popular TV show Antiques Roadshow.
After being carried from the house to the ambulance Ms Gibson-Watt fought like a "tigress" with members of the emergency services.
The inquest heard her mother Miranda Phillimore was called by her son-in-law to her daughter's home after the ambulance crew arrived at the scene on the evening of November 13.
She told the court she arrived to find her daughter in the back of the ambulance and said: "She was alarmingly strapped down with five people holding her down at the time."
In her witness statement Ms Phillimore, the daughter of 4th Baron Phillimore, said her daughter was "as wild as a tigress" in the ambulance, thrashing as she was being held down.
Describing how they had to carry the first-time mum by her shoulders and legs out of the house, paramedic Suzanne Elias, who was holding Chiara, said: "She was very distressed, she was shouting 'my baby is dead'.
"She was struggling a lot, but they carried her out to the ambulance."
She told the inquest jury paramedics didn't have restraining training, and if someone requires restraint then they would call for the support of police, who are trained.
She was admitted to the Lakeside Mental Health unit at the West Middlesex University Hospital in the hospital run by West London Mental Health Trust.
The coroner said: "She had another event on the November 15, 2012, on the ward.
"She was taken to a seclusion room for a few days and then went back to her bed on the ward.
"Then she suffered a cardiac arrest and she was taken to the intensive care unit at West Middlesex Hospital.
"It was while she was there it was decided she needed to go to theatre for urgent surgery and there was a tear found on her liver.
