PRE-LABOR RUPTURE OF MEMBRANES

DEFINITION ETIOLOGY DIAGNOSIS MANAGEMENT

classification TERM PROM PRETERM PROM

AGE OF GESTATION GESTATION

RISK TO THE PREGNANCY INCREASED RISK OF INFECTION TO MOTHER INCREASED RISK OF INFECTION TO BABY regardless of age of gest./ time of occurrence

LATENT PERIOD Interval between ROM and onset of labor Duration is inversely proportional to AOG

INCIDENCE Term PROM 2-10 % of pregnancies Preterm PROM 2- 3 % of pregnancies

ETIOLOGY Idiopathic PROM Infections Polyhydramnios Cervical incompetence Following cerclage or amniocentesis History of previous cervical surg. (conization) Uterine anomaly Domestic violence & trauma Trauma in VA

Other Causes Past OB history of PPROM Smoking Use of illegal drugs / substance abuse Stress Malnutrition Race

Many investigators and practitioners believe that infection (intrauterine) is one of the major predisposing events and causes of PPROM. - Mercer, 2003

DIAGNOSIS Hx of vaginal fluid leakage (amount, timing, odor, color, persistence) Sterile speculum exam to confirm PROM Assessment of cx status & exclusion of cord prolapse are appropriately done by speculum exam as well. ROUTINE PELVIC EXAM IS NOT RECOMMENDED! USG is not diagnostic, yet presence of normal AFV noted on USG makes dx of PROM less likely.

Speculum Exam Fluid pooling in posterior fornix Free flow of fluid from cervix

Other Tests Ferning, assessed by obtaining fluid sample, placing this on glass slide & allowing to air dry for 10 min. Micro. Observ. : characteristic arborization / ferning due to crystallization of NaCl pH testing of fluid using nitrazine paper (non- specific). Yellow nitrazine paper turns dark blue with pH above 6.5. Note normal vag. pH during pregnancy is and amniotic fluid ph is False pos. due to blood, vaginal infections, alkaline urine and presence of semen.

FLUID IN THE VAGINA due to PPROM may be collected to measure fetal lung maturity.

Complications of term PROM Fetal/neonatal infection Maternal infection Umbilical cord compression or cord prolapse

Complications of PPROM Preterm labor and preterm birth Fetal/neonatal infection Maternal infection Umbilical cord compression or prolapse Increased CS rate Pulmonary hypoplasia before 26 weeks AOG, & fetal deformation (Potter’s synd.)

Rx MANAGEMENT OF PROM, REGARDLESS OF AOG, REVOLVES AROUND MINIMIZING INFECTION TO THE MOTHER & HER BABY.

MANAGEMENT, any AOG Confirm dx. Assess maternal & fetal well-being. Determine presence of any associated condition requiring concurrent mx or indicating delivery. Avoid digital exam whenever possible. - if expectant mx is planned, assess cx during speculum exam. - if patient is in labor, digital cx exam is indicated. Determine fetal presn. using USG, if abdominal assessment is inconclusive.

Management of term PROM Avoid digital cervical exam. Inform woman of benefits & risks of induction, compared with expectant management. Assess for infection : monitor mat. PR & temp, FHR, pres. of uterine tenderness or irritability; changes in wbc, if indicated. Begin antibiotics if indicated. Administer appropriate antibiotics for chorioamnionitis.

Term PROM labor induction with oxytocin esp. in the presence of chorioamnionitis Term PROM study (Hannah,et.al. 1996) & Cochrane review : - Labor induction reduces risk of chorioamnionitis & endometritis, without increasing CS rate & operative vaginal births ; no difference in rates of neonatal infections.

Management of PPROM wks Avoid digital exam. Inform patient of risks & benefits. Assess for infections. Administer antibiotics if indicated. Induce labor esp. in the presence of chorioamnionitis, and in the absence of contraindications to labor or vag. delivery.

“ When PPROM occurs at wks AOG, the risk of severe acute neonatal morbidity & mortality with expeditious delivery is low. Conversely, conservative management at this AOG has been associated with 8-fold increase in amnionitis and only a brief prolongation of latency & maternal hospitalization, without significant reduction in perinatal morbidity related to prematurity.” (Mercer, 2004)

Management of PPROM < 34 wks Expectant management is usually preferred; attempts should be made to prolong latent period / latency. Expectant Mx includes monitoring of mat. VS & FHR, as well as uterine activity at specific intervals. Avoid digital exam. Amniotic fluid may be collected from vagina to assess fetal lung maturity. Perform USG to assess fetal position, cx status and AFV. Administer steroids to promote lung maturity. Assess and monitor for infections. Culture, if ind. Administer appropriate antibiotics for chorioamnionitis if it develops; and induction to follow.

Findings of 2004 meta-analysis in Cochrane Library of antibiotic treatment with PPROM (over 6000 women in 22 trials) : Use of antibiotics ff. PPROM reduced risk of chorioamnionitis, prolonged the latency period, reduced markers of neonatal morbidity (infection, use of surfactant & O2, abnormal cranial USG).

antibiotics Antepartum intravenous Ampicillin 1-2 grams every 4-6 hrs x 48 hours, plus Erythromycin 250 mg IV every 6 hrs x 48 hours; Followed by both ampicillin/amoxycillin ( mg by mouth every 8 hrs) & enteric- coated erythromycin base (333 mg every 8 hours) together orally for five days; Clindamycin alone 600 mg three times a day for penicillin-allergic patients.

PROM in HIV-AIDS patients MOTHER-TO CHILD TRANSMISSION OF HIV may increase when the membranes are ruptured. Prolonged ROM increases the risk of vertical transmission ! Once membranes are ruptured, labor induction should be considered in HIV+ women, esp. those with a high viral load, to reduce exposure of the fetus to the HIV. One needs to weigh the risk of HIV transmission with the risk of prematurity... give antenatal steroids and then induce labor. If the pregnant woman has AIDS, she is at an increased risk for infection. Her risk must be weighed against the risk of delivering a premature infant. Induction of labor is likely the best course of action to reduce risks to the woman’s health.

Note that cesarean section, once membranes are ruptured, no longer offers any protective factor. do CS only for usual OB indications.