Antibiotics for Preterm Labor

Since intrauterine infection is the most frequent cause of preterm birth, numerous trials have been attempted on the antibiotic treatment of various conditions. There is insufficient evidence to recommend treatment of genital tract infection in early pregnancy to reduce the prevalence of preterm birth. Routine antibiotics in pregnant women with preterm labor and intact membranes can have harmful effects on the neonatal outcome. Thus, antibiotic administration should be withheld unless obvious infection signs are observed. The efficacy of antibiotic administration has been established in prelabor premature rupture of membranes. However, clinicians should be cautious regarding the development of resistant organisms after prophylactic antibiotics. Once a pregnant woman is diagnosed with or suspected to have intrauterine infection, immediate initiation of antibiotic therapy is recommended. Since intrauterine infection is usually polymicrobial involving both aerobic and anaerobic bacteria, antibiotics should cover these microorganisms. The optimal antibiotic regimen has not been well-studied. Amniotic fluid sample obtained by transabdominal amniocentesis in pregnant women with suspected intrauterine infection can determine antibiotic susceptibility and the efficacy of an antibiotic treatment. Expectant management with antibiotic treatment may contribute to prolongation of pregnancy duration; however, strict observation of the fetal condition is necessary.