Family sources said Namita was 78 and bed-ridden for the last 12 years due to multiple health issues.
As the couple had no children, Namita had been living a lonely life in her last days at a south Kolkata flat where NGO 'India's Smile' and Dr Subhash's friend and professor Sunit Mukherjee had been taking care of her.
Dr Subhash is credited with having created the child, Durga, using in-vitro fertilisation (IVF). She was born just 67 days after the first IVF baby in the United Kingdom.
Eminent director Tapan Sinha had made a film 'Ek Doctor Ki Maut' (Death of a doctor) on his life and death.
To honour him, West Bengal Chief Minister Mamata Banerjee had recently announced that a chair would be instituted in a medical college and an award in his name would be given by the government.