My water broke over 2 days before DD was born, so I was on pretty massive IV antibiotics for about 24 hours.
The hospital did not require any additional monitoring or anything so that was not an issue.
As far as internal exams go, I think it's best to limit them as much as possible, anyways, but I'd certainly decline as many of them as you can. I did however allow a few when there were some questions about how DD was handling pit induced contractions. I was reasonably comfortable with them at that point as I knew we were getting towards the end, and I figured there wasn't much that was likely to have survived the amount of antibiotics I was on anyways.
Your breastmilk is still absolutely the best thing for your baby, antibiotics or not. The biggest concern regarding antibiotics and breastfeeding is that the lack of good bacteria can leave you more vulnerable to thrush. I made sure I was taking a good probiotic, and gave my DD a couple doses of a good, newborn safe infant probiotic as well to help re-establish a heathy bacterial environment.
My only other advice is to read up on the risk factors that increase the chances of GBS infection in infants (mostly PROM, premature birth and signs of infection like increasing temperature in the mother before birth) and make sure you know the symptoms too. From the research I've done, antibiotics in labour are very effective, but they are not 100% guaranteed to work. It's possible I'm just paranoid, but I sort of figure that if you've been treated, sometimes doctors will overlook the possibility that a baby may still end up with GBS, so I wanted to make sure that I knew what I was looking for too.
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