Prom is about 10 - 12% (GUNN) A prospertive study at NDGD hospital from November 2000 to July 2001 included 172 PROM patients with gestational age  36 weeks by Ampicillin 2g (IV). Result: Amnioninfection syndrome 9.88% compared without antibiotic prophylaxis is 16.97% (P = 0.023).