Reference: Fataawa Ramadhaan – Volume 1, Pages 361-362, Fatwa No.317
Majmoo’ Fataawa Ibn Baaz – Volume 3, Pages 209-210
Question: A woman’s postpartum blood flow ceased before the completion of forty days, so she took the ritual bath of purification and then after purifying herself she fasted the remainder of the days of Ramadhaan. It was then said to her that she must repeat the fasts she fasted before the completion of the forty days [after giving birth]. So what is the legal ruling regarding that, and is she required to repeat the fasts or not? And is it permissible to engage in sexual intercourse after purification [from postpartum bleeding] before the completion of the forty [days] or not? And if she purified herself from the menses before the completion of seven days, is it permissible for her to engage in sexual intercourse or not?
Response: If the situation was as mentioned in that she saw her postpartum blood flow had ceased before forty [days] and she took the ritual bath of purification and fasted, then her fast during those days before the completion of the forty days is valid and she is not required to make them up.
And there is no harm in her engaging in sexual intercourse during those days after her postpartum blood flow had ceased and [after] she had taken a ritual bath of purification before the forty [days]. And likewise, there is no harm in her engaging in sexual intercourse after her menses blood flow had ceased and [after] she had taken a ritual bath of purification before the seven days.