Is my wife permitted to break her fast in Ramadan due to her pregnancy and its accompanying symptoms? Does she only have to make up for the days (qada') or make up for them along with feeding the poor (qada' and it'am)? And how does she make up for the days from last Ramadan about which she is unsure?

A pregnant woman is permitted to break her fast if she fears for herself or her child. She is only required to make up the days (qada') if she broke her fast fearing for herself. However, if she broke her fast fearing for her child, then according to Imam Shafi'i and Imam Ahmad, she must make up the days and feed one poor person for each day. It is permissible to rely on the information provided by a trustworthy doctor regarding this. If that is not possible, then she may act based on what she predominantly believes. Days about which there is doubt regarding their make-up must be made up. As for delaying making up the fasts until after the following Ramadan (definition), if it was due to a valid excuse, then she only needs to make up the days. But if it was without a valid excuse, then in addition to making up the days, she must feed one poor person for each day.