Preterm Premature Rupture of Membranes : Antibiotics

• Antibiotics are indicated to prolong latency and reduce the risk of early onset neonatal group B streptococcal (GBS) infection, as well as for treatment of overt intraamniotic infection, if present.
• The regimen of prophylactic antibiotics is given for seven days to patients at <34 weeks of gestation at the time of membrane rupture

Prophylaxis

• Infection may lead to spontaneous preterm labor or may be the indication for medically-indicated preterm delivery. 
• The goal of antibiotic therapy is to reduce the frequency of maternal and fetal infection and thereby delay the onset of preterm labor (ie, prolong latency) and the need for preterm delivery 

Rationale

• Ampicillin specifically targets group B streptococcus, many aerobic gram-negative bacilli, and some anaerobes. 
• Azithromycin specifically targets Ureaplasmas, which can be important causes of chorioamnionitis in this setting. 
• Azithromycin also provides coverage of Chlamydia trachomatis, which is an important cause of neonatal conjunctivitis and pneumonitis

  References:

1. NAG 2014
2. www.uptodate.com
3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3964356/
4. http://www.aafp.org/afp/2011/0501/p1106.html
5. https://www.rcog.org.uk/en/guidelines-research-services/guidelines/preterm-prom-in-a-group-b-strep-positive-woman---query-bank/