Ampicillin (2-g dose every 6 hours) and erythromycin (250 mg dose every 6 hours) for 48 hours IV followed by oral amoxicillin (250 mg dose every 8 hours) and erythromycin base (333 mg dose every 8 hours) for 5 days in fetuses > 24 weeks'.

   REFERENCE:

Mercer BM, Miodovnik M, Thurnau GR, Goldenberg RL, Das AF, Ramsey RD, Rabello YA, Meis PJ, Moawad AH, Iams JD, Van Dorsten JP, Paul RH, Bottoms SF, Merenstein G, Thom EA, Roberts JM, McNellis D.
Antibiotic therapy for reduction of infant morbidity after preterm premature rupture of the membranes. A randomized controlled trial. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. JAMA. 1997 Sep 24;278(12):989-95. PMID:9307346