Rupture of membrane (ROM) after 37 weeks gestation is a harbinger of labor, but if ROM does not result is labor in 4 hours it is called premature ROM (PROM).
By definition PROM always occurs at 37 weeks or later. If before 37 weeks, we call it preterm premature ROM (PPROM).
When the history suggests ROM at any age the first think you have to do is a speculum exam. The typical history is sudden gush of clear fluid per vagina, but many women may complain of intemittent or continuous leakage or feeling constantly wet. You see pooling of fluid in the posterior fornix? that's it. You see fluid coming out of cervical os? that's it. You are in doubt? do Nitrazine and Ferning test to make sure you are dealing with amniotic fluid. AVOID digital vaginal exam as it is associated with increased risk of infection.
So the very first step is ALWAYS speculum exam, NOT steroids, NOT antibiotics, NOT anything else unless the diagnosis of ruptured membranes is certain. If in doubt, perform Nitrazine and Ferning tests to make sure. If there still inconsistencies between the Hx and the Ph/Ex, US steps in to confirm the Dx.
Second step regardless of the gestational age is CTG and US for assessment of fetal wellbeing. The rest depends on the PROM vs. PPROM:
PROM
If the GBS status is positive or there are other indications dictating prophylaxis against GBS regardless of PROM, start intravenous antibiotics now. The first choice is benzylpenicillin intravenously; clindamycin if there is hypersensitivity to penicillins. Otherwise just wait.
- If PROM lasts beyond 18 hours start prophylaxis against GBS.
- Induce labor using oxytocin once the patient is not in labor in 24 hours.
- No need for steroids and fetal maturity is adequate.
- No need for transfer as the baby is already matured.
- No WCC and CRP monitoring.
PPROM
- The first thing to consider is steroids. IM betamethasone comes first, dexamethasone is next if betamethasone is not available. Steroids are used to prevent respiratory distress syndrome, intraventricular hemorrhage and necrotizing enterocolitis.
- Tocolysis using nifedipine or salbutamol are only indicated if the patient has contractions. Tocolysis should be maintained for 48 hours until steroids establish their effects. Their use beyond 48 hrs is controversial as contractions may be the only sign of subclinical intrauterine infections that is a very strong indication to terminate the pregnancy ASAP.
- Transfer to a tertiary facility where there is a Neonatal Intensive Care Unit (NICU), in case premature delivery occurs. No matter how far it is.
- Antibiotic prophylaxis should be commenced in the tertiary hospital after low and high vaginal swabs are taken. If there is a delay, prophylactic antibiotics should be started before transfer. Coverage is again GBS. Two days of IV followed by 3 days of oral if the patient can tolerate.
- Recommence the antibiotics once labor establishes. We are talking about prophylaxis here not treatment of established infections. If intrauterine infection develops we start the patient on Gentamicin + ampicillin/amoxicillin + metronidazole (all IV) and we induce labor ASAP.
- Perform CTG every 2-3 days. If abnormal, consider chorioamnionitis. Start gentamicin + ampicillin/amoxicillin + metronidazole and do IOL.
- Perform white cell count and CRP. If WCC≥15000 or CRP>40, start treatment for chorioamnionitis and do IOL. If there is uterine tenderness OR altered color of vaginal discharge or maternal fever then it is chorioamnionitis. Antibiotics as above and IOL again.