وَإِذَا حَاضَتِ الْمَرْأَةُ، أَوْ نَفِسَتْ: أَفْطَرَتْ، وَقَضَتْ إِذَا طَهُرَتْ.
Translation: When a woman menstruates or experiences postnatal bleeding, she does not continue fasting and makes up the affected fasts after attaining purity.
The third clause names menstruation and postnatal bleeding together. The fast is not maintained in those states; missed days are made up after purity.
This is not exactly the same as the concession to a traveller or an ill person. Menstruation and postnatal bleeding are impediments to a valid fast during their occurrence.