PREMATURE RUPTURE OF MEMBRANES


PROM = rupture of membranes before onset of labor, either at term or preterm
Induction of labor has been traditionally used to theoretically reduce risk of infection

PROM AT TERM:

I. NEJM 334:1005, 1996-JW

  1. Multicenter trial randomized 5000 women at >37wks gestation and PROM to induction with pit; induction with PGE2 vaginal gel; or expectant management (waiting up to 4d if no maternal or fetal compromise) then induction with pit or PGE2
  2. Labor induced in about 20% of expectant management group
  3. Neonatal infection rates similar in all groups (about 3%)
  4. C-section rates similar in all groups (about 10%)
  5. Maternal chorioamnionitis less frequent in induction/pit group than expectant/pit group (4% vs. 8.6%); ditto postpartum fever (1.9% vs. 3.6%)
  6. Pt satisfaction sl. greater with induction than expectant management

II. The following were significant predictors of neonatal infection in PROM in a multicenter study of 5,028 pts (Am. J. Obs. Gyn. 179:635, 1998--JW)

  1. Maternal chorioamnionitis
  2. Maternal Group-B streptococcal colonization
  3. > 6 vaginal examinations before delivery
  4. > 24h between ROM and onset of active labor (whether spontaneous or induced)
  5. Maternal receipt of antibiotics before delivery

 

PRETERM PROM:

I. Dietary Vitamin C intake < 10%ile during months before conception and during 2nd trimester was ass'd with elevated risk of preterm PROM in a prospective cohort study of 1944 low-to-moderate income women (Am. J. Obs. Gyn. 189:519, 2003--JW)

II. General approach before 34 weeks is to wait until can prove fetal lung maturity unless some urgent need to induce labor, e.g. infection, and in the mean time give broad-spectrum abx and steroids.

III. 77 women with PROM at 24-34 weeks, no evidence of infection, and documented fetal lung immaturity, and no digital vaginal exam since PROM were randomized to betamethasone (12mg IM, repeated at 24h then Qwk) vs. no steroids. All were given 3g Unasyn. No difference in mean time to delivery, rates of maternal infection, or rates of induction for fetal lung maturation. However, less RDS in babies of women who got steroids (18% vs. 44%, sig.). No differences in rates of neonatal infection or mortality. (Obs. Gyn 88:801, 1996-AFP)

IV. Antibiotics for PPROM

  1. JAMA 278:989, 1997
  1. 614 women with PPROM at 24-32wks who hadn't received steroids or abx in the previous week were randomized to abx (ampicillin 2g IV Q6h + erythromycin 250mg ?route Q6h both x 48h then amox 250 PO Q8h + erythromycin base 333mg Q8h both x 5d) vs. placebo.
  2. Women were screened for GBS and treated if they had it.
  3. Incidence of combined endpoint (fetal or infant death, resp. distress, severe intraventricular hemorrhage, NEC stage 2 or 3, or sepsis < 72h after birth) was 44% in tx group vs. 53% in control group (sig. diff.)
  4. Avg. time lapse between ROM and delivery sig. longer w/abx (6d vs. 3d)
  5. Concluded that "all women undergoing expectant management of PPROM should receive abx prior to the onset of labor, regardless of GBS carrier status"

 

Antibiotics for PROM at term & preterm:

  1. In a meta-analysis of 19 randomized studies, use of abx after PROM was associated with sig. reduction in chorioamnionitis (RR 0.57) and neonatal infection (RR 0.67) and length of NICU stay (5d less).  Use of amoxicillin-clavulanate was associated with higher incidences of necrotizing enterocolitis than other antibiotics Note--Summary didn't say whether these we term, preter, or both.  (Obs. Gyn. 104:1051, 2005--AFP)