Shamima Begum's new born son has died in a displaced people's camp in northern Syria.
Three week old Jarrah's death certificate said he'd died of pneumonia.
Begum left London for Syria in 2015 with two other schoolgirls to marry fighters from so-called Islamic State and has since had her British citizenship revoked.
Britain's Interior Minister Saji Javid had been criticised for not arranging for Jarrah to come to Britain where he was a national.
Javid said it would have been very difficult to arrange but repeated visits by foreign journalists to the displaced people's camp suggest it's a relatively secure location in Syria.
The Red Crescent in Syria may also have been able to assist the British government in repatriating Jarrah to Britain.
Previously Begum lost her other two children to ill-health in Syria.
She had been sheltering in the Hol camp featured below in a video by the International Committee of the Red Cross and Crescent but was forced to move, reportedly because she received death threats. She is now sheltering in another camp near the Iraqi border.
Begum's Dutch husband Yago Riedijk, who was a so-called Islamic State fighter, told British broadcaster Sky that both of them had been brainwashed by the group.
He called his wife, whom he had married as a child at the age of 15, a "young naive girl".
Last week he said wanted to return to the Netherlands with Begum and their son.
Begum's parents are from Bangladesh but neither that country's government nor her family say she is a dual citizen.
However the British government says she is and so hasn't been made stateless by having her citizenship revoked.
Begum told the Times newspaper in February that she didn't regret joining so-called Islamic State but had admitted it was corrupt and oppressive.
"When I saw my first severed head in a bin it didn't faze me at all. It was from a captured fighter seized on the battlefield, an enemy of Islam," she told the reporter who first discovered her in the camp.