B’Sha’ah Tovah!
Healthy pregnant and breastfeeding women are required to fast on Tisha B’Av unless there are specific health concerns. Please consult with your doctor about the advisability of fasting.
If you are medically permitted to fast, you should prepare beforehand by drinking significant amounts of water (beyond the normal amount needed for a pregnant/breastfeeding mother) for a number of days leading up to the fast. You should rest during the fast as much as possible, staying indoors in a cool/air-conditioned room. You should also arrange to have help with your toddler that day. If you still are breastfeeding at that point, you should have bottles available in case you feel your milk is running low.
If you start to feel any signs of dehydration, beyond the usual headache and lethargy associated with fasting, you may begin drinking (any liquid, not just water). If drinking does not help you recover somewhat, you may eat as necessary.
Please feel free to get back to us with any further questions.