ORIGINAL CONTRIBUTION Maternal and Fetal Outcomes of Spontaneous Preterm Premature Rupture of Membranes Lee C. Yang, DO; Donald R. Taylor, DO; Howard H. Kaufman, DO; Roderick Hume, MD; Byron Calhoun, MD The authors retrospectively evaluated maternal and fetal reterm premature rupture of membranes (PROM) at outcomes of 73 consecutive singleton pregnancies com- P16 through 26 weeks of gestation complicates approxi- plicated by preterm premature rupture of amniotic mem- mately 1% of pregnancies in the United States and is associ- branes. When preterm labor occurred and fetuses were at ated with significant risk of neonatal morbidity and mor- tality.1,2 a viable gestational age, pregnant patients were managed Perinatal mortality is high if PROM occurs when fetuses aggressively with tocolytic therapy, antenatal corticos- are of previable gestational age. Moretti and Sibai 3 reported teroid injections, and antenatal fetal testing. The mean an overall survival rate of 50% to 70% after delivery at 24 to gestational age at the onset of membrane rupture and 26 weeks of gestation. delivery was 22.1 weeks and 23.8 weeks, respectively. The Although neonatal morbidity remains significant, latency from membrane rupture to delivery ranged despite improvements in neonatal care for extremely pre- from 0 to 83 days with a mean of 8.6 days. Among the mature newborns, neonatal survival has improved over 73 pregnant patients, there were 22 (30.1%) stillbirths and recent years. Fortunato et al2 reported a prolonged latent phase, low infectious morbidity, and good neonatal out- 13 (17.8%) neonatal deaths, resulting in a perinatal death comes when physicians manage these cases aggressively rate of 47.9%. The perinatal survival rate based on gesta- with active expectant management using tocolysis and pro- tional age at the onset of fetal membrane rupture was 12.1% phylactic antibiotics. at less than 23 weeks of gestation, 60% at 23 weeks, and In previous studies,3–5 investigators generally excluded 100% at 24 to 26 weeks. Maternal morbidity was minimal newborns with chorioamnionitis or pregnant patients whose with puerperal endomyometritis in 5 (6.8%) cases, one of deliveries occurred shortly after PROM or on hospital admis- which became septic; however, there was no long-term sion. By excluding these patients from study protocols, out- sequela. Eight (15.7%) liveborn infants had pulmonary comes—especially in the latency period—might appear better than expected. Therefore, this retrospective study aims to hypoplasia, 5 (62.5%) of which resulted in neonatal death. evaluate the outcome of every consecutive singleton preg- In 33 (45.2%) patients, amniotic membranes ruptured nancy complicated by PROM that occurred when fetuses before 23 weeks of gestation. At previable gestational age, were at 16 to 26 weeks of gestation. Patients were treated at the risk of neonatal pulmonary hypoplasia appears to be Rockford Memorial Hospital in Illinois, a regional perinatal primarily dependent on gestational age at the onset of center, from January 1995 to December 2001. premature rupture of membrane rather than gestational age at delivery. Pregnancy outcomes remain dismal when the Methods fetal membrane ruptures before 23 weeks of gestation. From January 1995 to December 2001, 73 pregnant patients who had preterm PROM at 16 to 26 weeks of gestation received medical care at Rockford Memorial Hospital. These patients were identified through the perinatal computer database and neonatal delivery logbooks. Institutional approval for a chart review was obtained from the Rockford Memorial Hospital Investigation Review Board. Midtrimester PROM is defined as rupture of amniotic From Saint Alexius Medical Center in Hoffman Estates, Ill (Yang) and Rock- membranes occurring between 16 and 26 weeks of gestation.5 ford Memorial Hospital, also in Ill (Taylor, Kaufman, Hume, and Calhoun). Address correspondence to: Lee C. Yang, DO, Perinatology Clinic, Saint When fetuses were at viable gestational age (ie, 24 weeks of ges- Alexius Medical Center, 1555 Barrington Rd, Hoffman Estates, IL 60194-1018. tation), pregnant patients who had PROM were given tocolytic E-mail: [email protected] therapy if they went into spontaneous preterm labor, as well Yang et al • Original Contribution JAOA • Vol 104 • No 12 • December 2004 • 537 ORIGINAL CONTRIBUTION as antenatal corticosteroids, fetal moni- injection until delivery or up to toring, and prophylactic antibiotics. For Table 1 34 weeks of gestation). women whose fetuses were at previable Rupture of Membranes: Through 1999, all pregnant gestational age during PROM, physi- Distribution of Gestational patients with PROM received weekly cians opted instead to observe patients Age at Onset (N=73) steroid injections until delivery or on an outpatient basis and then admitted 34 weeks of gestation. However, them to the hospital at viability. Gestational Age, wk No. (%)* since 2000, weekly or multiple courses Initially, each patient was admitted of antenatal corticosteroid injections are 16 4 (5.5) to a labor and delivery suite for maternal no longer recommended.6 and fetal assessment. After maternal con- 17 4 (5.5) Clinical chorioamnionitis was dition was stabilized and there was no diagnosed by the attending physician evidence of fetal distress when the fetus 18 ... if two or more of the following symp- was viable, ultrasound evaluation was 19 6 (8.2) toms were present: maternal pyrexia performed to assess fetal presentation, (Ͼ38Њ C[Ͼ100.4Њ F]) in conjunction growth, anatomy, and the level of amni- 20 10 (13.7) with uterine tenderness, purulent otic fluid. At the discretion of the vaginal discharge, or fetal tachycardia. 21 2 (2.7) attending physician, amniocentesis was If amniocentesis was performed, the performed to rule out infection. 22 7 (9.6) presence of organism or positive cul- Gestational age was estimated ture—with or without low glucose using the date of the patient’s last men- 23 15 (20.5) levels (Ͻ14 mg/dL)—would also be strual period and/or ultrasound dating. 24 5 (6.8) indicative of infection. The attending physician ordered an Indications for delivery included ultrasound evaluation for every patient 25 13 (17.8) clinical chorioamnionitis, non-reassuring after hospital admission. Pelvic exami- 26 7 (9.6) assessment for fetal well-being, fetal nation using a sterile speculum was per- death, advanced labor, or failed tocol- formed. Digital examination was ysis. If infection was identified, delivery avoided unless the patient was com- was expedited and the use of broad- * Percentages reported were rounded for each mitted to delivery. Diagnosis of preterm group by gestational age. Therefore, the sum spectrum antibiotics was initiated. PROM was based on history and con- of these percentages may not equal 100%. Following delivery, all newborns firmed by the presence of pooled amni- were admitted to the neonatal inten- otic fluid on a sterile speculum, positive sive care unit and antibiotic therapy results from a ferning test, and transvaginal ultrasonographic with ampicillin and gentamicin sulfate were initiated while the evaluation that demonstrated oligohydramnios. Amnioinfu- results of the septic work up were prepared. As a routine eval- sion with warm physiologic saline solution and instillation of uation for potential intraventricular hemorrhage, roentgenog- indigo carmine permitted a more comprehensive ultrasono- raphy of the head was ordered by the attending physician for graphic evaluation to assist attending physicians in the diag- all newborns at 1 week of age—and as needed thereafter. nosis of oligohydramnios. Diagnosis of respiratory distress syndrome was based Each patient was observed in the labor and delivery suite on clinical and physical signs of respiratory distress and radio- for at least 24 hours. At viability, external fetal monitoring graphic characteristics of the chest. Bronchopulmonary dys- assessed fetal well-being. Patients without evidence of infec- plasia was defined as the need for oxygen supplementation at tion were transferred to the high-risk maternal ward. Antenatal 36 weeks of gestational age. assessment included daily nonstress tests and an evaluation every 4 hours of patients’ vital signs and body temperatures. Results Fetal growth was assessed every 3 to 4 weeks by ultra- Among the 73 patients included in this retrospective study, the sound. At viability, patients with spontaneous preterm labor mean maternal age was 26 years (range 16–38 years). but no evidence of infection were treated with intravenous Thirty (41.1%) patients were nulliparous. Thirteen (17.8%) magnesium sulfate (MgSO4) and prophylactic antibiotics: patients had a history of tobacco use, seven (9.6%) had a his- ampicillin sodium or, for patients with a hypersensitivity to tory of preterm delivery, and 8 (11%) had a history of preterm penicillin, erythromycin. Treatment with MgSO4 was stopped PROM. and calcium channel blocker (20 mg of nifedipine orally every During the current pregnancy, 3 (4.1%) patients under- 6 hours) was started as a maintenance tocolysis once uterine went cervical cerclage. Of the 3 patients who underwent this quiescence was achieved for at least 48 hours. Patients received procedure, 2 cases were prophylactic and 1 was rescue. two intramuscular injections of antenatal corticosteroids (12 mg Among these 73 patients, the gestational age distribution of betamethasone every 24 hours followed by a single weekly at the onset of PROM (Table 1) ranged between 16 and 538 • JAOA • Vol 104 • No 12 • December 2004 Yang et al • Original Contribution ORIGINAL CONTRIBUTION Table 2 Rupture of Membranes: Perinatal Outcome by Gestational Age (N=73) Stillbirth Neonatal death Survival Gestational Age, wk No. (%)* No. (%) Ͻ23 33 (45.2) 20 (60.6) 9 (27.3) 4 (12.1) 23 15 (20.5) 2 (13.3) 4 (26.7) 9 (60) 24 to 26 25 (34.2) ... ... 25 (100) Total 73 (100) 22 (30.1) 13 (17.8) 38 (52.1) * Percentages reported were rounded for each group by gestational age. Therefore, the sum of these percentages may not equal 100%. 26.9 weeks (mean 22.1 weeks; median 23 weeks). The mean ges- treated with broad-spectrum antibiotics, recovering without tational age at delivery was 23.8 weeks and the mean latency any sequela.