Antimicrobials for Preterm Birth Prevention: An Overview

Table 2

Studies of specific use of antibiotics for preterm birth prevention.

Study	N	Antibiotic regimen	Gestational age at treatment (wks)	Days treatment	Primary outcomes	Benefit
Hauth et al. (1995) [53]	624	PO metronidazole + PO erythromycin	22–24	7/14	Gestational age at delivery Rate of preterm delivery	Yes; (26% versus 36% rate of preterm delivery, 𝑃=0.01)
McDonald et al. (1997) [54]	897	PO metronidazole	24–29	2 doses	Reduction in Spontaneous birth less than 37 weeks	Yes; (9.1% versus 41.7% reduction, OR 0.14, CI 0.01–0.84)
Carey et al. (2000) [67]	1953	PO metronidazole	16–24; 24–30	2 doses	Rate of delivery before 37 weeks	No
Ugwumadu et al. (2003) [56]	6210	PO clindamycin	12–22	5	Spontaneous preterm delivery and late miscarriage	Yes; (10.4% reduction in miscarriages and PTD,𝑃=0.0003)
Trichomonas vaginalis
Klebanoff et al. (2001) [55]	617	PO metronidazole	16–23; 24–29	2 doses	Rate of delivery before 37 weeks	No
Kigozi et al. (2003) [57]	206	PO azithromycin, cefixime, metronidazole	Any gestation	1 dose	(1) Birth weight; (2) Rate of preterm birth; (3) 2-year mortality rate	No
Other relevant studies
Interconception; Andrews et al. (2006) [69]	124	PO azithromycin + PO metronidazole	4 months after delivery	2 doses/7 days every 4 months until next pregnancy	Subsequent rate of preterm birth or miscarriage	No
Fetal Fibronectin +; Andrews et al. (2003) [58]	703	PO metronidazole + PO erythromycin	21–25.6	10	Spontaneous delivery less than 37 weeks	No
Fetal Fibronectin +; Shennan et al. (2006) [59]	109	PO metronidazole	24–27	7	Spontaneous preterm delivery less than 30 weeks	No