Sheikh Sulaymân al-`Isâ, professor at al-Imâm University in Riyadh
Someone who engages in sexual intercourse during the day in Ramadan has to fast two months continuously. The person may carry out these sixty consecutive days during the wintertime, when the days are cold and short. If, during this period, someone has to break his or her fast for a valid reason such as travel, sickness or menstruation, he or she may desist from fasting during that time and continue fasting from where he or she left off until completing the required two months.
Only a person who is truly incapable of fasting 60 consecutive days can opt to feed 60 poor people instead.
In the case of a woman who is pressured by her husband into sexual intercourse during the day time of Ramadan or who is ignorant of the ruling that is unlawful for her to have sex while fasting, she will be exempted and she has no expiation to make. However, she will still have to remake the fast for the one day she missed because she had intercourse.
And Allah knows best.
Source: Islam Today