I know several people who have had a variety of experiences being GBS positive. I know one woman who was GBS positive with her first two vaginal births, received the antibiotics during labor and experienced no complication. I know another woman whose baby became sick because she was GBS positive and didn't go to the hospital soon enough to receive antibiotics after her water broke. I know another woman whose baby was very cranky after she received antibiotics during labor and her baby received them intravenously postpartum. I wasn't GBS positive with my first son, but he did receive antibiotics intravenously for about a week after birth, and he was a very cranky baby, too. I've often wondered if the antibiotics contributed to the problem.
In any case, I was caught off guard by this development at my 36 week visit. It's easy, when you are pregnant the fourth time, to think that everything will be just the same as your previous three. This is especially so when your previous three were so similar to each other (similar baby weights, similar feel during labor, similar gestational delivery dates, similar aches and pains during pregnancy, for example). I've heard of yeast infections being more common in diabetics during pregnancy. I suppose the same could apply to other kinds of bacterial imbalances in the birth canal, I had just never experienced one.
In any case, I took probiotics following the GBS positive diagnosis, and I did receive antibiotics during labor (three doses). IV antibiotics are given 4 hours apart, and the doctors like for you to have at least two doses before baby is born, believing that is sufficient to reduce the risk of infection for the baby. I do suspect, as I almost always suspect when antibiotics are involved with newborns, that it may have made my little man cranky for the first few days after birth. I have no definitive proof of that, only a series of anecdotes, but the suspicion grows over time.
So next time, I think I will take the probiotics before the GBS test. If it's still positive, I will ask them to test again a little closer to my due date (because, let's be honest, I never go into labor before the last week of pregnancy). I hope to avoid antibiotics again in the future, though I will almost certainly take them again if I'm still GBS positive at birth.