My understanding is that it's safe with frequent monitoring after 42 weeks. DD was actually born at 42+3 (41+4 by the 'official' date). The OB was a bit taken aback when I told him we wouldn't be getting induced at 42 weeks just because they urged me to.
The community midwifery program would take homebirths till 43 weeks.
With both my babies having longer gestations and no problems whatsoever I figure it's just the way I bake them.