According to terrorism researcher Magnus Ranstorp, roughly 65 women have returned to Sweden after spending time in an ISIS-held area, and most of them have one or two children.
Ranstorp told Swedish Radio that the returning children tend to have experienced "horrific things", including stress, violence, violent military training and intense ideological indoctrination.
He added that ISIS use children as informants against their parents, creating an immense sense of insecurity.
In addition, boys as young as nine have been recruited as soldiers, and girls are deemed ready to marry, too, from the age of nine.
When these children return to Sweden, there are no national guidelines on how to care for them.
Among five social services that Swedish Radio contacted, only Gothenburg has a strategy for these kinds of cases.
A year ago, Bettan Byvald, a social worker in Angered, Gothenburg, asked the intelligence and security police, Säpo, for more information about the families of returning ISIS fighters.
Things are better now, she says, and they have received a number of reports from Säpo. But in Örebro, for example, the social services do not have specific protocols to deal with these children, but treat them as individual cases, like all other children.
"If we were to find out about this, we are prepared, just like with all other children. We will act immediately," said Lena Mantler, head of social services in Örebro.