A bequest to a child in womb is valid under Muslim law, if the child is born alive within

Under Muslim law a bequest to a child in the womb is valid if the child is born alive within "6 months of the date of will under Sunni Law and within 10 months under Shia Law". The child must already be conceived when the will is made; a bequest to a person not yet conceived fails. Three or four months is not the period under either school.