gynecology and obstetrics
Preterm Labor
Key Points
Do anovaginal cultures for group B streptococci and cultures to check for any clinically suspected infections that could have triggered preterm labor (eg, pyelonephritis, STIs). Treat with antibiotics effective against group B streptococci pending culture results. If the cervix dilates, consider tocolysis with magnesium sulfate, a calcium channel blocker, or, if the fetus is ≤ 32 weeks, a prostaglandin inhibitor. Give a corticosteroid if the fetus is ≥ 24 weeks and < 34 weeks (in some cases < 37 weeks). Consider giving corticosteroids starting at gestational age 23 weeks if there is a risk of preterm delivery within 7 days. Consider magnesium sulfate if the fetus is < 32 weeks. In future pregnancies, consider giving a progestin to prevent recurrence. 