Antibiotic Use in Pregnancy - Update

Use of antibiotics during pregnancy and risk of spontaneous abortion - CMAJ

Interesting outcomes - we already don’t use tetracyclines and quinolones in pregnancy, so the miscarriage risk is not too relevant for those. I was surprised about macrolides being higher risk. Nitrofurantoin is fine, which I did not find surprising given its does not have good distribution anywhere but bladder.

Septra also has a higher risk, and it is recommended a second line tx for UTI in pregnancy, so that may need reassessed. However, the guidelines also stipulate avoiding use in first trimester due to the potential for fetal abnormalities (not miscarriage, but as with tetracyclines/quinolones, you are already avoiding its use). Given the study focused on 20 weeks and earlier, it looks like not much needs changing in current practice, except maybe the use of macrolides.

Good Medscape Summary Here