MEDICAL TREATMENT :
1. PREMATURE RUPTURE OF MEMBRANES :
Most patients (90%) enter spontaneous labor within 24 hours when they experience ROM at term. The major question regarding management of these patients is whether to allow them to enter labor spontaneously or to induce labor. In large part, the management of these patients depends on their desires; however, the major maternal risk at this gestational age is intrauterine infection. The risk of intrauterine infection increases with the duration of ROM. Evidence supports the idea that induction of labor, as opposed to expectant management, decreases the risk of chorioamnionitis without increasing the cesarean delivery rate.
Hannah et al studied 5041 women with PROM who were randomly assigned to induction of labor with intravenous oxytocin or vaginal prostaglandin E2 gel versus expectant management for as many as 4 days with induction of labor for complications. They concluded that in women with PROM, induction of labor and expectant management resulted in similar rates of cesarean delivery and neonatal infection. However, induction with oxytocin resulted in a lower risk of maternal infection (endometritis) when compared with expectant management. Additionally, the women in the study viewed induction of labor more favorably than expectant management.
Other smaller studies have shown results with higher cesarean and/or operative delivery rates when the cervix was unfavorable.
At term, infection remains the most serious complication associated with PROM for the mother and the neonate. The risk of chorioamnionitis with term PROM has been reported to be less than 10% and to increase to 24% after 24 hours of PROM. This points out the importance of appropriate management strategies for PROM at term.
Since risk of infection at term with ROM is small during the first 24 hours, expectant management and waiting for spontaneous labor may be considered in selected patients for the first 12-24 hours if a patient desires expectant management. The use of expectant management after the first 24 hours is questionable.
Digital vaginal examinations should be avoided until labor is initiated; however, fetal presentation should be documented to avoid discovering malpresentation of the fetus long after admission for ROM. All patients with ROM should be asked to come to the hospital to ensure fetal well being.
The neonatal risks of expectant management of PROM include infection, placental abruption, fetal distress, fetal restriction deformities and pulmonary hypoplasia, and fetal/neonatal death. Fetal death does occur in approximately 1% of patients with PROM who have been expectantly managed.
The primary determinant of neonatal morbidity and mortality is gestational age at delivery, again stressing the importance of conservative management when possible.
In general, prognosis is good after 32 weeks' gestation as long as no other complicating factor, such as congenital malformation or pulmonary hypoplasia, exists.
2. PREMATURE PRETERM RUPTURE OF MEMBRANES :
PPROM occurring from 24-37 weeks' gestation is far more difficult to manage than PROM at term. Several issues need to be considered in formulating a plan of management. Prematurity is the principal risk to the fetus, while infection morbidity and its complications are the primary maternal risks. All plans for management of PPROM remote from term should include the family and the medical team caring for the pregnancy, including the neonatal and maternal medical team. Remote from term, PPROM should only be cared for in facilities where a NICU is available and capable of caring for the neonate. Because most PPROM pregnancies deliver within a week of ROM, transfer of the pregnant mother to a qualified facility is urgent and should be facilitated immediately upon diagnoses.
The vast majority of women proceed to active labor and deliver soon after PPROM. With appropriate therapy and conservative management, approximately 50% of all remaining pregnancies deliver each subsequent week after PPROM. Thus, very few women remain pregnant more than 3-4 weeks after PPROM. This is important information to give the woman considering expectant management remote from viability.
Spontaneous sealing of the membranes does occur occasionally (<10% of all cases), mostly after PPROM that has occurred subsequent to amniocentesis; however, this is the exception rather than the rule.
Several areas of controversies exist regarding the best medical approach or management of PROM remote from term. Expectant management and immediate delivery are potential options in these patients, and each has its own advantages and disadvantages. With appropriate care, the maternal risks of expectant management are generally accepted to be minimal and a clear neonatal advantage exists by reducing risks of prematurity.
Controversies exist as to interventions such as steroids for acceleration of lung maturity, antibiotics, and tocolytics.
MATERNAL & FETAL SURVEILLANCE : After an initial period of continuous monitoring of fetal heart rate and uterine contractions (24-48 h), if findings are suggestive of reassuring surveillance, then the patient would be a candidate for expectant management. The patient should be placed on the obstetric floor for bed rest. Because bed rest in pregnancy is associated with an increased chance of deep venous thrombosis, prophylaxis to reduce this risk should be instituted. Fetal monitoring should be performed at least once a day. If evidence of frequent cord compression is present as determined by moderate-to-severe variables, continuous monitoring should be reinstituted. Maternal vitals need to be monitored closely. Tachycardia and fever are both suggestive of chorioamnionitis and require careful evaluation to determine the presence of intra-amniotic infections, in which case delivery and initiation of broad-spectrum antibiotics should be promptly facilitated.
Ultrasonographic examination for amniotic fluidindex and fetal growth and well being should be used liberally to ensure appropriateness of continued expectant management. While oligohydramnios, defined as an amniotic fluid index of less than 2 cm, has been associated with short latency and chorioamnionitis, it alone is not an indication for delivery when other means of surveillance are reassuring. White blood cell count is not predictive of outcome and does not need to be monitored other than to support clinical suspicion of chorioamnionitis.
Digital cervical examinations should be avoided. In a noncephalic presentation, especially with a dilated cervix, continuous monitoring should be considered to avoid missing the diagnosis of cord prolapse.
Intra-amniotic infection should invoke prompt delivery. Practitioners should have a low threshold for diagnosing infection in a patient with PPROM as evidence clearly shows poor outcome in an infected neonate compared with a similar uninfected neonate.
PPROM IN THE SECOND TRIMESTER :
PPROM prior to fetal viability is a unique problem that is often difficult to manage. The major maternal risk is infection, namely chorioamnionitis. The major morbidity in the fetus with midtrimester ROM is lethal pulmonary hypoplasia from prolonged, severe, early oligohydramnios.
With appropriate therapy and conservative management, approximately 50% of all remaining pregnancies deliver each subsequent week after PPROM (Mercer, 2005). When PPROM occurs prior to 20 weeks' gestation, the probability of reaching viability is less than 5% and the risk of pulmonary hypoplasia due to oligohydramnios and underdevelopment of alveolar structures and the tracheobronchial tree is present.
The risk of infection increases with the duration of PPROM. Outpatient management of PPROM prior to viability is appropriate in the well-informed and educated patient. The patient needs to be informed of warning signs that indicate the need for immediate evaluation. These signs include fever, abdominal pain, vaginal spotting, foul-smelling discharge, and rapid heart rate. The woman should monitor her temperature at home at least 3 times daily and report any elevation beyond 100.4°F (38°C). Frequent examinations are necessary to ensure maternal safety. Patients must be educated about the warning signs of intra-amniotic infection, and they must take their temperature 3 times a day at home. After viability is reached, inpatient management needs to be considered.
Midtrimester (13-26 wk) PPROM has a dismal prognosis. Expectant management may be appropriate in select patients who are well informed and educated about the risks and the dismal prognosis for the neonate. Delivery is also appropriate when the mother is concerned about her own risks, especially when PPROM has occurred prior to 20 weeks' gestation. Incomplete abortion may be the appropriate term for the condition, as products of conception (the amniotic fluid) have passed the cervical opening and into the vagina in these cases.
Survival varies with gestational age at diagnosis (from 12% when diagnosed at 16-19 wk, to as much as 60% when diagnosed at 25-26 wk). Until viability, maternal safety should be the primary concern.
MANAGEMENT OF PPROM :
The initial evaluation of PPROM should include a sterile speculum examination to document ROM. Cervical cultures including Chlamydia trachomatis and Neisseria gonorrhoeae and anovaginal cultures for Streptococcus agalactiae should be obtained. Maternal vital signs should be documented as well as continuous fetal monitoring initially to establish fetal status. Ultrasonographic documentation of gestational age, fetal weight, fetal presentation, and amniotic fluid index should be established. Digital examination should be avoided, but visual inspection of the cervix can accurately estimate cervical dilatation. Digital examination of the cervix with PPROM has been shown to shorten latency and increase risk of infections without providing any additional useful clinical information.
In certain circumstances, immediate delivery of the fetus with PPROM is indicated. These circumstances include chorioamnionitis, advanced labor fetal distress, and placental abruption with nonreassuring fetal surveillance. If fetal lung maturity has been documented by either amniocentesis or collection of vaginal fluid, delivery should be facilitated. In a noncephalic fetus with advanced cervical dilatation, the risk of cord prolapse may also outweigh the benefits of expectant management and delivery should be considered.
If after initial evaluation of the mother and fetus, they are both determined to be clinically stable, expectant management of PPROM may be considered to improve fetal outcome. The primary maternal risk with expectant management of PPROM is infection. This includes chorioamnionitis (13-60%), endometritis (2-13%), sepsis (<1%), and maternal death (1-2 cases per 1000). Complications related to placenta include abruption (4-12%) and retained placenta or postpartum hemorrhage requiring uterine curettage (12%).
The risks and potential benefits of expectant management should be discussed with the patient and her family, and informed consent should be obtained. The maternal and fetal status need to be reevaluated daily, and the safety and potential benefits of expectant management should be reassessed. If the condition remains stable, the immature fetus may benefit from expectant management, even if for a short period, to allow administration of steroids and antibiotics. Once maturity has been reached, the benefit from expectant management of PPROM is unclear and the risks of infection outweigh any potential benefits.
MEDICAL TREATMENT OF PPROM :
Antibiotics :
The initial step in management of PPROM is informed consent. The patient needs to be given risks and benefits information and must participate in decision making. Once the decision to manage a patient expectantly has been made, the institution of broad-spectrum antibiotics should be considered. Multiple trials have examined the advantages and disadvantages of using antibiotics and the choice of antibiotics. In most studies, use of antibiotics has been associated with prolongation of pregnancy and reduction in infant and maternal morbidity. However, a few studies have reported increased neonatal morbidity with certain types of antibiotics, as discussed below.
Two of the largest studies that have looked at the efficacy of antibiotic use in PPROM are the National Institute of Child Health and Human Development - Maternal Fetal Medicine Units (NICHD-MFMU) study of PROM and the ORACLE trial. In the NICHD study, intravenous antibiotics were used for 48 hours—ampicillin 2 g q6h and erythromycin 250 mg q6h. The patients were then placed on oral amoxicillin 250 mg q8h and enteric-coated, erythromycin-base 333 mg every q8h to complete a 7-day course of antibiotic therapy. In this study, the control group, compared with the antibiotic group, had a significantly shorter duration of latency. The antibiotic group was twice as likely to remain undelivered after 7 days. The increased latency continued for up to 3 weeks after discontinuation of antibiotics. Composite and individual morbidities for the neonate were lower in the antibiotic group. The incidence of chorioamnionitis and neonatal sepsis, including group B streptococci sepsis, was decreased.
The ORACLE trial used erythromycin alone, amoxicillin clavulanic acid alone, or amoxicillin clavulanic acid in combination with erythromycin. Their results were different in that no significant difference was noted in latency to delivery and neonatal morbidity was not decreased as defined in their primary outcome (death, chronic lung disease, and major cerebral abnormality on ultrasonography). Decreased need for supplemental oxygen and positive blood culture results were apparent. When amoxicillin clavulanic acid was used either alone or in combination with erythromycin, an increased risk of necrotizing enterocolitis (1.9% vs 0.5%, p=0.001) was present.
Based on current evidence, 7 days of antibiotics, as proposed by the NICHD-MFMU study of PROM, should be the antibiotic regimen used in patients with PPROM who are being managed expectantly. When another antibiotic is being used for other indications, such as a urinary tract infection, attempts should be made to avoid duplicated therapy. For example, a patient being treated with a cephalosporin for a urinary tract infection does not need penicillin therapy. Therapy longer than 7 days should be avoided; it has not been shown to be more effective and may promote the emergence of resistance organisms.
Antenatal corticosteroid treatment :
The use of corticosteroids to accelerate lung maturity should be considered in all patients with PPROM with a risk of infant prematurity from 24-34 weeks' gestation. The latency period has been suggested to be too short for the effects of corticosteroids to make a difference in neonatal morbidity; however, this clearly does not appear to be the case. Most patients with PPROM remain pregnant at 48 hours and thus will benefit from corticosteroid therapy. The use of steroids has also been suggested to increase the risk of infection. However, the current evidence does not support this concern based on individual studies and meta-analyses; no difference (either higher or lower rates of infections) has been observed with corticosteroid use.
In contrast to these concerns, data indicate that the use of corticosteroids reduces neonatal morbidity and mortality. The rates of respiratory distress syndrome (RDS), necrotizing enterocolitis, and intraventricular hemorrhage were all lower when either 12 mg of betamethasone IM was given twice in a 24-hour interval or dexamethasone 6 mg q12h was given for 4 doses.
Tocolytics :
The most common cause of labor in the setting of PPROM is underlying chorioamnionitis. The use of tocolysis in that setting is not justified. No data indicate that administering tocolysis benefits the neonate. In one study, prophylactic tocolysis was found to briefly prolong latency. In another study by Jazayeri et al, latency was shorter when magnesium sulfate was given. The use of tocolysis, unlike corticosteroids and antibiotics, should be considered only when a clear clinical benefit exists, such as in transport of the mother to a tertiary institution with a NICU, and should not be used routinely.