Widmer, abducted from the province of Balochistan with her partner David Och in July last year, would already have been pregnant when she was captured.
Meanwhile, negotiations with the Taliban for the release of the hostages have failed, newspaper Neue Zürcher Zeitung reported Sunday.
The militant group, Tehrik-e-Taliban, is holding the hostages in north-western Pakistan. The group do not usually mistreat their prisoners, and are known more to use hostages as bargaining chips for ransom.
So far messages have been passed between both sides through tribal elders and religious dignitaries. The Pakistani government refuses to negotiate directly with terrorists.
However according to an anonymous source, talks broke down after 15 paramilitaries were killed in attacks on Taliban units in December, the newspaper reported.
In October, a video showing the two hostages was posted on the internet. In the clip, the couple request officials to give in to the kidnappers’ demands.
This was the first in a line of kidnappings of foreigners since July last year. Most recently, two European aid workers, one German and one Italian, were abducted from where they were staying in Multan City in the province of Punjab.