Systematic review on the management of term prelabour rupture of membranes

INTRODUCTION

Prelabour rupture of membranes at term affects approximately 10% of women during pregnancy, and it is often associated with a higher risk of infection than when the membranes are intact. In an attempt to control the risk of infection, two main approaches have been used most widely in clinical practice: induction of labour (IOL) soon after the rupture of membranes, also called active management (AM), and watchful waiting for the spontaneous onset of labour, also called expectant management (EM). In addition, previous studies have demonstrated that vaginal examinations increase the risk of chorioamnionitis. However, the effect of vaginal examinations in the context of prelabour rupture of membranes have not been researched to the same extent.

METHODS

This systematic review analyses and critiques the latest research on the management of term prelabour rupture of membranes, including the effect of vaginal examinations during labour, with a focus on the outcomes of both normal birth, and chorioamnionitis. Due to its complexity, three research questions were identified using the PICO diagram, and subsequently, the results from these searches were combined. The systematic review aimed to identify randomised controlled trials (RCTs) and observational studies that compared active vs expectant management, included number of vaginal examinations and had chorioamnionitis and/or normal birth as outcomes. The following databases were used: MEDLINE, EMBASE, Maternity and Infant care, LILACS, CINAHL and the Cochrane Central Register of Controlled trials. Quality was assessed using a tool developed especifically for this study that included questions from CASP and the Cochrane risk of bias tool. Due to the high degree of heterogeneity meta-analysis was not deemed appropriate. Therefore, simple narrative analysis was carried out.

RESULTS

Thirty-two studies met the inclusion criteria, of which 27 were RCTs and 5 observational studies. The overall quality of the studies wasn't high, 15 out of the 32 studies were deemed to be low quality and only 17 out of 32 studies were deemed to be of intermediate quality. The systematic review revealed that the management of term prelabour rupture of membranes continues to be controversial. Previous research has compared active management (Induction of labour shortly after the rupture of membrane) against expectant management (watchful waiting for the spontaneous onset of labour). Although previous studies have demonstrated that vaginal examinations increase the risk of chorioamnionitis, no prospective studies have included an intervention to reduce the number of vaginal examinations.

CONCLUSION

A RCT assessing the consequences of active management and expectant management as well as the effect of vaginal examinations during labour for term prelabour rupture of membranes is necessary.

Management of clinical chorioamnionitis: an evidence-based approach

This review aimed to examine the existing evidence about interventions proposed for the treatment of clinical chorioamnionitis, with the goal of developing an evidence-based contemporary approach for the management of this condition. Most trials that assessed the use of antibiotics in clinical chorioamnionitis included patients with a gestational age of ≥34 weeks and in labor. The first-line antimicrobial regimen for the treatment of clinical chorioamnionitis is ampicillin combined with gentamicin, which should be initiated during the intrapartum period. In the event of a cesarean delivery, patients should receive clindamycin at the time of umbilical cord clamping. The administration of additional antibiotic therapy does not appear to be necessary after vaginal or cesarean delivery. However, if postdelivery antibiotics are prescribed, there is support for the administration of an additional dose. Patients can receive antipyretic agents, mainly acetaminophen, even though there is no clear evidence of their benefits. Current evidence suggests that the administration of antenatal corticosteroids for fetal lung maturation and of magnesium sulfate for fetal neuroprotection to patients with clinical chorioamnionitis between 24 0/7 and 33 6/7 weeks of gestation, and possibly between 23 0/7 and 23 6/7 weeks of gestation, has an overall beneficial effect on the infant. However, delivery should not be delayed to complete the full course of corticosteroids and magnesium sulfate. Once the diagnosis of clinical chorioamnionitis has been established, delivery should be considered, regardless of the gestational age. Vaginal delivery is the safer option and cesarean delivery should be reserved for standard obstetrical indications. The time interval between the diagnosis of clinical chorioamnionitis and delivery is not related to most adverse maternal and neonatal outcomes. Patients may require a higher dose of oxytocin to achieve adequate uterine activity or greater uterine activity to effect a given change in cervical dilation. The benefit of using continuous electronic fetal heart rate monitoring in these patients is unclear. We identified the following promising interventions for the management of clinical chorioamnionitis: (1) an antibiotic regimen including ceftriaxone, clarithromycin, and metronidazole that provides coverage against the most commonly identified microorganisms in patients with clinical chorioamnionitis; (2) vaginal cleansing with antiseptic solutions before cesarean delivery with the aim of decreasing the risk of endometritis and, possibly, postoperative wound infection; and (3) antenatal administration of N-acetylcysteine, an antioxidant and antiinflammatory agent, to reduce neonatal morbidity and mortality. Well-powered randomized controlled trials are needed to assess these interventions in patients with clinical chorioamnionitis.

Evidence base multi-discipline critical strategies toward better tomorrow for very preterm infants

Despite advances in neonatal intensive care in the recent decade, a large number of very preterm infants (VPIs) remain at risk for significant neurodevelopmental impairment (NDI). Given that there are many interventions need to be implemented during the critical perinatal period so that complications of these vulnerable VPIs could be minimized, it is urgent to develop multi-discipline strategies based on evidence to be carried out. The objective of this new term evidence-based perinatal critical strategies (EBPCS), is to provide beneficial intervention towards better neurodevelopmental outcomes, specifically for preterm infants below 28 weeks gestational age. EBPCS is defined as the management of the VPIs during the perinatal period which would include antenatal counseling with team briefing and share decision making, treat the chorioamnionitis, antenatal MgS04, antenatal steroid, delayed cord clamping/milking, neonatal resuscitation team preparation, prevention of hypothermia, immediate respiratory support with continuous positive airway pressure at delivery room, less invasive surfactant administration, early surfactant with budesonide therapy, support of cardiovascular system, early initiate of probiotics administration, early caffeine, early parenteral and enteral nutrition, promptly initiating antibiotics. These critical strategies will be discussed detail in the text; nonetheless, standardized protocols, technical skills and repeated training are the cornerstones of successful of EBPCS. Further experience from different NICU is needed to prove whether these very complicate and comprehensive perinatal critical strategies could translate into daily practice to mitigate the incidence of NDI in high-risk VPIs.

Reproductive services for the patient at increased risk for morbidity and mortality during the second trimester

Some complications of pregnancy that occur in the second trimester, such as preeclampsia, bleeding placenta previa, and preterm premature rupture of membranes, require delivery to avoid maternal morbidity and mortality. When these situations occur before fetal viability, pregnancy termination, either by induction of labor or dilation and evacuation, can be lifesaving. To optimize maternal health in these situations, Maternal Fetal Medicine providers should be trained to provide all needed medical services, including termination. Currently, only the minority of Maternal Fetal Medicine providers are skilled in dilation and evacuation. Training programs should focus on ways to facilitate training in second trimester dilation and evacuation to improve care access and quality when these medically necessary procedures are needed for women in whom a healthy pregnancy is no longer an option.

The fetal inflammatory response syndrome: the origins of a concept, pathophysiology, diagnosis, and obstetrical implications

The fetus can deploy a local or systemic inflammatory response when exposed to microorganisms or, alternatively, to non-infection-related stimuli (e.g., danger signals or alarmins). The term "Fetal Inflammatory Response Syndrome" (FIRS) was coined to describe a condition characterized by evidence of a systemic inflammatory response, frequently a result of the activation of the innate limb of the immune response. FIRS can be diagnosed by an increased concentration of umbilical cord plasma or serum acute phase reactants such as C-reactive protein or cytokines (e.g., interleukin-6). Pathologic evidence of a systemic fetal inflammatory response indicates the presence of funisitis or chorionic vasculitis. FIRS was first described in patients at risk for intraamniotic infection who presented preterm labor with intact membranes or preterm prelabor rupture of the membranes. However, FIRS can also be observed in patients with sterile intra-amniotic inflammation, alloimmunization (e.g., Rh disease), and active autoimmune disorders. Neonates born with FIRS have a higher rate of complications, such as early-onset neonatal sepsis, intraventricular hemorrhage, periventricular leukomalacia, and death, than those born without FIRS. Survivors are at risk for long-term sequelae that may include bronchopulmonary dysplasia, neurodevelopmental disorders, such as cerebral palsy, retinopathy of prematurity, and sensorineuronal hearing loss. Experimental FIRS can be induced by intra-amniotic administration of bacteria, microbial products (such as endotoxin), or inflammatory cytokines (such as interleukin-1), and animal models have provided important insights about the mechanisms responsible for multiple organ involvement and dysfunction. A systemic fetal inflammatory response is thought to be adaptive, but, on occasion, may become dysregulated whereby a fetal cytokine storm ensues and can lead to multiple organ dysfunction and even fetal death if delivery does not occur ("rescued by birth"). Thus, the onset of preterm labor in this context can be considered to have survival value. The evidence so far suggests that FIRS may compound the effects of immaturity and neonatal inflammation, thus increasing the risk of neonatal complications and long-term morbidity. Modulation of a dysregulated fetal inflammatory response by the administration of antimicrobial agents, anti-inflammatory agents, or cell-based therapy holds promise to reduce infant morbidity and mortality.

Management of Chorioamnionitis-Exposed Infants in the Newborn Nursery Using a Clinical Examination-Based Approach

BACKGROUND

Antibiotic use in well-appearing late preterm and term chorioamnionitis-exposed (CE) infants was reduced by 88% after the adoption of a care approach that was focused on clinical monitoring in the intensive care nursery to determine the need for antibiotics. However, this approach continued to separate mothers and infants. We aimed to reduce maternal-infant separation while continuing to use a clinical examination-based approach to identify early-onset sepsis (EOS) in CE infants.

METHODS

Within a quality improvement framework, well-appearing CE infants ≥35 weeks' gestation were monitored clinically while in couplet care in the postpartum unit without laboratory testing or empirical antibiotics. Clinical monitoring included physician examination at birth and nurse examinations every 30 minutes for 2 hours and then every 4 hours until 24 hours of life. Infants who developed clinical signs of illness were further evaluated and/or treated with antibiotics. Antibiotic use, laboratory testing, and clinical outcomes were collected.

RESULTS

Among 319 initially well-appearing CE infants, 15 (4.7%) received antibiotics, 23 (7.2%) underwent laboratory testing, and 295 (92.5%) remained with their mothers in couplet care throughout the birth hospitalization. One infant had group B Streptococcus EOS identified and treated at 24 hours of age based on new-onset tachypnea and had an uncomplicated course.

CONCLUSIONS

Management of well-appearing CE infants by using a clinical examination-based approach during couplet care in the postpartum unit maintained low rates of laboratory testing and antibiotic use and markedly reduced mother-infant separation without adverse events. A framework for repeated clinical assessments is an essential component of identifying infants with EOS.

American Association of Pro-Life Obstetricians & Gynecologists. AAPLOG practice bulletin no. 3: Previable induction of labor for chorioamnionitis

When intrauterine infection develops prior to viability, prognosis for the fetus is guarded. Previable partuition can be pursued when infection is present, but physician must challenge themselves to do only what is indicated and avoid causing unnecessary effects by their methods of terminating pregnancy.

Amnioinfusion for chorioamnionitis

BACKGROUND

Chorioamnionitis is a leading cause of perinatal morbidity and mortality. Amnioinfusion aims at reducing the adverse effects of chorioamnionitis by dilution of the infective organisms or by an anti-microbial effect of the fluid infused.

OBJECTIVES

The objective of this review was to determine the effect of amnioinfusion on clinical and sub-clinical chorioamnionitis, fetal well-being, fetal heart rate characteristics and perinatal and maternal morbidity and mortality.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (6 July 2016), PubMed, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (6 July 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised clinical trials (RCTs) of amnioinfusion (treatment group) versus no amnioinfusion in women with chorioamnionitis.We would have also considered trials comparing amnioinfusion with sham amnioinfusion; different types or volumes of amnioinfusion fluid but none were identified.Cluster-RCTs and quasi-RCTs were eligible for inclusion but none were identified. We identified one study published in abstract form but it did not contain any numerical data and has therefore been excluded. Studies using a cross-over design are not an appropriate study design and thus were not eligible for inclusion in this review.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed potential studies for inclusion and assessed trial quality. Both review authors independently extracted data and data were checked for accuracy.

MAIN RESULTS

We included one small trial (with data from 34 participants) comparing transcervical amnioinfusion with no amnioinfusion. The trial was considered to be at a high risk of bias overall, due to small numbers, inconsistency in the reporting and lack of information on blinding. Meta-analysis was not possible. Transcervical amnioinfusion was with room temperature saline at 10 mL per minute for 60 minutes, then 3 mL per minute until delivery versus no amnioinfusion. All women received intrauterine pressure catheter, acetaminophen and antibiotics (ampicillin or, if receiving Group B beta streptococcal prophylaxis, penicillin and gentamycin). We did not identify any trials that used transabdominal amnioinfusion.Compared to no amnioinfusion, transcervical amnioinfusion had no clear effect on the incidence of postpartum endometritis (risk ratio (RR) 1.50, 95% confidence interval (CI) 0.29 to 7.87; absolute risk 176/1000 (95% CI 34 to 96) versus 118/1000;low-quality evidence). Nor was there a clear effect in the incidence of neonatal infection (RR 3.00, 95% CI 0.13 to 68.84; absolute risk 0/1000 (95% CI 0 to 0) versus 0/1000; low-quality evidence). The outcome of perinatal death or severe morbidity (such as neonatal encephalopathy, intraventricular haemorrhage, admission to intensive/high care) was not reported in the included trial.In terms of this review's secondary outcomes, the rate of caesarean section was the same in both groups (RR 1.00, 95% CI 0.35 to 2.83; absolute risk 294/1000 (95% CI 103 to 832) versus 294/1000; low-quality evidence). There was no clear difference in the duration of maternal antibiotic treatment between the amnioinfusion and no amnioinfusion control group (mean difference (MD) 16 hours, 95% CI -1.75 to 33.75); nor in the duration of hospitalisation (MD 3.00 hours, 95% CI -15.49 to 21.49). The study did not report any information about how many babies had a low Apgar score at five minutes after birth.Women in the amnioinfusion group had a lower temperature at delivery compared to women in the control group (MD -0.38°C, 95% CI -0.74 to -0.02) but this outcome was not pre-specified in the protocol for this review.The majority of this review's secondary outcomes were not reported in the included study.

AUTHORS' CONCLUSIONS

There is insufficient evidence to fully evaluate the effectiveness of using transcervical amnioinfusion for chorioamnionitis and to assess the safety of this intervention or women's satisfaction. We did not identify any trials that used transabdominal amnioinfusion. The evidence in this review can neither support nor refute the use of transcervical amnioinfusion outside of clinical trials. We included one small study that reported on a limited number of outcomes of interest in this review. The numbers included in this review are too small for meaningful assessment of substantive outcomes, where reported. For those outcomes we assessed using GRADE (postpartum endometritis, neonatal infection, and caesarean section), we downgraded the quality of the evidence to low - with downgrading decisions based on small numbers and a lack of information on blinding. The included study did not report on this review's other primary outcome (perinatal death or severe morbidity).The reduction in pyrexia, though not a pre-specified outcome of this review, may be of relevance in terms of benefits to the fetus of reduced exposure to heat. We postulate that the temperature reduction found may be a direct cooling effect of amnioinfusion with room temperature fluid, rather than reduction of infection. Larger trials are needed to confirm and extend the findings of the trial reviewed here. These should be randomised controlled trials; participants, women with chorioamnionitis; interventions, amnioinfusion; comparisons, no amnioinfusion; outcomes, maternal and perinatal outcomes including neurodevelopmental measures.Further research is justified to determine possible benefits or risks of amnioinfusion for chorioamnionitis, and to investigate possible benefits of reducing temperature in fetuses considered at risk of neurological damage. Research should include randomised trials to examine transcervical or transabdominal amnioinfusion compared with no infusion for chorioamnionitis and examine outcomes listed in the methods of this review.

[Management of preterm prelabor rupture of membranes with respect to the inflammatory complications - our experiences]

OBJECTIVE

Preterm prelabor rupture of membranes is responsible for approximately one third of all preterm deliveries. The most common complications associated with this pregnancy pathology are microbial invasion of the amniotic cavity, intraamniotic inflammation, intraamniotic infection and histological chorioamnionitis. This article explains these complicatioss and their relation to the optimal management of preterm prelabor rupture of membranes.

DESIGN

Overview study.

SETTING

Department of Obstetrics and Gynecology, Charles University in Prague, Faculty of Medicine and University Hospital Hradec Kralove.

METHODS

To analyze current knowledge and our own experiences regarding inflammatory complications of preterm prelabor rupture of membranes.

CONCLUSION

Inflammatory complications of preterm prelabor rupture of membranes are associated with risk of development of early onset sepsis. Nevertheless, gestational age is a main confounder affecting neonatal morbidity and mortality.

Hyperthermia, inflammation, and perinatal brain injury

Hyperthermia at the time of or following a hypoxic-ischemic insult has been associated with adverse neurodevelopmental outcome. Moreover, an elevation in temperature during labor has been associated with a variety of other adverse neurologic sequelae such as neonatal seizures, encephalopathy, stroke, and cerebral palsy. These outcomes may be secondary to a number of deleterious effects of hyperthermia including an increase in cellular metabolic rate and cerebral blood flow alteration, release of excitotoxic products such as free radicals and glutamate, and hemostatic changes. There is also an association between chorioamnionitis at the time of delivery and cerebral palsy, which is thought to be secondary to cytokine-mediated injury. We review experimental and human studies demonstrating a link between hyperthermia and perinatal brain injury.

Practice variation in late-preterm deliveries: a physician survey

OBJECTIVE

Late-preterm (LPT) neonates account for over 70% of all preterm births in the US. Approximately 60% of LPT births are the result of non-spontaneous deliveries. The optimal timing of delivery for many obstetric conditions at LPT gestations is unclear, likely resulting in obstetric practice variation. The purpose of this study is to identify variation in the obstetrical management of LPT pregnancies.

STUDY DESIGN

We surveyed obstetrical providers in North Carolina identified from North Carolina Medical Board and North Carolina Obstetrical and Gynecological Society membership lists. Participants answered demographic questions and six multiple-choice vignettes on management of LPT pregnancies.

RESULT

We obtained 215/859 (29%) completed surveys which are as follows: 167 (78%) from obstetrics/gynecology, 27 (13%) from maternal-fetal medicine, and 21 (10%) from family medicine physicians. Overall, we found more agreement on respondents' management of chorioamnionitis (97% would proceed with delivery), mild pre-eclampsia (84% would delay delivery/expectantly manage) and fetal growth restriction (FGR) (80% would delay delivery/expectantly manage). We found less agreement on the management of severe preeclampsia (71% would proceed with delivery), premature preterm rupture of membranes (69% would proceed with delivery) and placenta previa (67% would delay delivery/expectantly manage). Management of LPT pregnancies complicated by preterm premature rupture of membranes, FGR and placenta previa vary by specialty.

CONCLUSION

Obstetrical providers report practice variation in the management of LPT pregnancies. Variation might be influenced by provider specialty. The absence of widespread agreement on best practice might be a source of modifiable LPT birth.

Diagnosis and management of clinical chorioamnionitis

Chorioamnionitis is a common complication of pregnancy associated with significant maternal, perinatal, and long-term adverse outcomes. Adverse maternal outcomes include postpartum infections and sepsis whereas adverse infant outcomes include stillbirth, premature birth, neonatal sepsis, chronic lung disease, and brain injury leading to cerebral palsy and other neurodevelopmental disabilities. Research in the past 2 decades has expanded understanding of the mechanistic links between intra-amniotic infection and preterm delivery as well as morbidities of preterm and term infants. Recent and ongoing clinical research into better methods for diagnosing, treating, and preventing chorioamnionitis is likely to have a substantial impact on short and long-term outcomes in the neonate.

Clinical management of intra-amniotic infection and chorioamnionitis: a review of the literature

Intra-amniotic infection (IAI), or chorioamnionitis, complicates up to 10% of all pregnancies and up to 2% of labors at term. There is a significant risk of complications for the mother and the neonate following IAI, including sepsis and pneumonia. In addition, there is a correlation between IAI and premature rupture of membranes, preterm premature rupture of membranes, preterm labor, and preterm birth. Research in the last decade has also revealed a complex and significant association between IAI and cerebral palsy and other central nervous system damage in both the preterm and term fetus. Timely diagnosis and treatment of IAI can significantly reduce the risk of both maternal and neonatal complications.

Impact of subclinical chorioamnionitis on maternal and neonatal outcomes

BACKGROUND

Chorioamnionitis is considered to be one of the main causes of preterm labor and has been associated with an adverse perinatal outcome in preterm infants. The controversy about the benefits/risks of delaying labor is a critical issue concerning the management of chorioamnionitis.

METHODS

The database between July 2001 and March 2006 was reviewed for women with singleton pregnancies between 22 and 28 weeks of gestation and with chorioamnionitis diagnosed on admission by amniotic fluid neutrophil elastase level. Women were classified according to the severity of chorioamnionitis (group A, amniotic fluid neutrophil elastase level of 0.15-1 microg/ml; B, 1-10 microg/ml; and C, > or = 10 microg/ml). During expectant management, serum C-reactive protein levels monitored the remission and aggravation of chorioamnionitis. Following deliveries, placentas were examined for histologic chorioamnionitis.

RESULTS

One hundred women were enrolled (group A, 38; B, 34; C, 28). The latency period until delivery was significantly longer in group A than in groups B and C. C-reactive protein levels just before delivery were higher than those on admission in 61% of the overall cases. Histologic chorioamnionitis and funisitis were manifested in 90.4% and 65.5%, respectively. Intrauterine fetal demise (4 cases) and neonatal and postneonatal deaths during admission (10 cases) were observed. Bronchopulmonary dysplasia was the most common major morbidity noted in groups B and C.

CONCLUSION

Chorioamnionitis could be controlled but is hard to cure. Higher levels of amniotic fluid neutrophil elastase are associated with a shorter interval from admission to delivery in women with subclinical chorioamnionitis.

Chorioamnionitis with or without funisitis increases the risk of hypotension in very low birthweight infants on the first postnatal day but not later

OBJECTIVE

To evaluate the relation between chorioamnionitis and hypotension in very low birthweight infants.

METHODS

Retrospective cohort study in infants with a birth weight of <1500 g born between January 2002 and September 2004. The placentas were examined for evidence of chorioamnionitis and funisitis. Hypotension was defined by the use of vasopressors.

RESULTS

Of 105 infants, 37 (35%) were chorioamnionitis positive. The onset of hypotension had a skewed distribution: day 1 for 30 episodes and scattered from day 2 to day 19 for the remaining 22. Of the 30 infants who developed hypotension on day 1, 17 (57%) were chorioamnionitis positive. The mean maturity of the chorioamnionitis positive group was 27.91 weeks, marginally less than the mean maturity of 29.05 weeks of the chorioamnionitis negative group (p = 0.05). After adjustment of the effects for confounding variables (birth weight, gestation, surfactant therapy, mechanical ventilation on day 1, high frequency oscillatory ventilation, patent ductus arteriosus), chorioamnionitis was the significant factor in line with hypotension developing on day 1 (adjusted odds ratio 5.14, 95% confidence interval 1.51 to 17.50). There was no evidence that hypotension developing after day 1 was associated with chorioamnionitis.

CONCLUSIONS

There is a strong association between chorioamnionitis and hypotension developing on day 1 in very low birthweight infants.

[Diagnosis and management of infection and its role in preterm labor]

OBJECTIVE

Analysis of contemporary knowledge of infection and its role in etiology and pathogenesis of preterm labor.

DESIGN

Review article.

SETTING

Department of Gynecology and Obstetrics, 1st Faculty of Medicine, Charles University, Prague.

METHODS

An overview of published data.

CONCLUSION

Infection is considered the most significant cause of preterm labor. The current research tend towards searching for local cervicovaginal markers of infection. An important role in the prenatal care is played by cervical ultrasonography which together with cervicovaginal markers can sort out the group of women with high risk of the preterm labor. Cervicovaginal markers can reveal microbial invasion into higher parts of the birth canals during the intrapartal care and justify the administration of antibiotics especially to women with the premature rupture of membranes. The routine administration of antibiotics was reevaluated in the management of preterm labor. The question of optimal antibiotics remains open.

An Evidence-Based Approach to the Evaluation and Treatment of Premature Rupture of Membranes: Part I

Preterm premature rupture of membranes (PPROM) occurs in 3% of pregnancies and is responsible for one third of all preterm births. PPROM will affect 120,000 women in the United States each year. It is associated with significant maternal, fetal, and neonatal morbidity and mortality resulting from infection, umbilical cord compression, abruptio placentae, and prematurity. The etiology is multifactorial, but the most significant risk factors are previous preterm birth and previous preterm premature rupture of membranes. Accurate diagnosis is extremely important to assure proper treatment. Evaluation is based on patient history and clinical examination. This review presents the available evidence and grades it according to the U.S. Preventative Task Force recommendations. In part I of this review, the definition, pathophysiology, and methods of PPROM diagnosis are presented. In part II, the management, treatment, neonatal outcome, and the maternal and fetal evaluation of women with PPROM in the presence of cerclage and medical complications is reviewed.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to define the term: preterm premature rupture of membranes, to list the factors associated with premature rupture of membranes, and to outline the tests available for the diagnosis of intra-amniotic infection.

The Maternal-Fetal Medicine Units cesarean registry: chorioamnionitis at term and its duration-relationship to outcomes

OBJECTIVE

The purpose of this study was to evaluate the relationship between chorioamnionitis and its duration to adverse maternal, fetal, and neonatal outcomes.

STUDY DESIGN

This was a 13-university center, prospective observational study. All women at term carrying a singleton gestation who underwent primary cesarean from January 1, 1999 to December 31, 2000 were eligible. Data abstraction was systematic and performed by trained research nurses. Selected adverse outcomes were compared between pregnancies with, and without, clinically diagnosed chorioamnionitis using relative risks (RRs) and 95% CIs. The duration of chorioamnionitis was stratified into 5 intervals (<or=3 h,>3-6 h,>6-9 h,>9-12 h, and>12 h), and respective outcomes compared by Mantel-Haenszel test for trend. Additionally, regression analysis was used to compute odds ratios (ORs) and 95% CIs for chorioamnionitis duration length as a continuous explanatory variable.

RESULTS

16,650 pregnancies were analyzed, 1965 (12%) with chorioamnionitis, which was associated with significantly increased risks of maternal blood transfusion, uterine atony, septic pelvic thrombophlebitis, and pelvic abscess (RR 2.3-3.7), as well as 5-minute Apgar <or=3, neonatal sepsis, and seizures (RR 2.1-2.8). By test of trend, only uterine atony (P <.01), maternal blood transfusion (P=.03), maternal admission to intensive care unit (P=.02), and 5-minute Apgar <or=3 (P <.01) were associated with duration of chorioamnionitis. By logistic analysis, only uterine atony (OR for each hour of chorioamnionitis 1.03, 95% CI 1.00-1.06), 5-minute Apgar <or=3 (OR 1.09, 95% CI 1.00-1.16), and neonatal mechanical ventilation within 24 hours of birth (OR 1.07, 95% CI 1.01-1.12) were significantly associated with chorioamnionitis duration.

CONCLUSION

Chorioamnionitis was associated with increased rates of morbidity after cesarean at term. The duration of chorioamnionitis, however, was not related to most measures of adverse maternal or fetal-neonatal outcome.

Infection with Ureaplasma urealyticum: is there a specific clinical and radiological course in the preterm infant?

BACKGROUND

Despite having mild early respiratory disease, many preterm babies develop chronic lung disease (CLD). Intrauterine infection with Ureaplasma urealyticum has been associated with preterm labour and CLD.

OBJECTIVE

To test the hypothesis that infection with U urealyticum results in a specific clinical and radiological picture in the first 10 days of life.

METHODS

Retrospective study of 60 ventilated babies < 30 weeks gestation, who had tracheal secretions tested for U urealyticum. Placental histology was reviewed by a paediatric pathologist for signs of chorioamnionitis. Chest radiographs were independently reviewed by two paediatric radiologists according to previously agreed criteria. All reviewers were blinded to the infection status of the babies.

RESULTS

Twenty five babies were U urealyticum positive. These were more likely to experience chorioamnionitis (p = 0.004), premature rupture of membranes (p = 0.01), and spontaneous vaginal delivery (p = 0.09). U urealyticum positive babies had fewer signs of respiratory distress syndrome on early chest radiographs (p = 0.038), and they could be weaned from their ventilation settings (fraction of inspired oxygen (FIO(2)) and mean airway pressure) more quickly in the first few days. Subsequently U urealyticum positive babies deteriorated clinically and radiologically. More often they required ventilation to be restarted (p = 0.051), a higher proportion being ventilated on day 10 (p = 0.027) with higher FIO(2) (p = 0.001) and mean airway pressure (p = 0.002). Their chest radiographs showed more emphysematous changes as early as day 5 (p = 0.045), with a pronounced difference by day 10 (p = 0.009).

CONCLUSIONS

Preterm ventilated babies with U urealyticum in their tracheal secretions have a different clinical and radiological course, with less acute lung disease but early onset of CLD, compared with those with negative cultures.

Post-partum endomyometritis diagnosis and treatment: A review

Over the past 80 years, obstetrical treatment strategies devised to control current problems have resulted in the emergence of new types of infection. These, in turn, have caused modifications in diagnostic techniques and treatment specifics. Currently, the two most obvious changes influencing post-partum infection care are shortened post-partum hospital care, and the widespread use of intra-partum antibiotics to prevent early onset Group B streptococcal sepsis in the newborn. In the present review, risk factors for post-partum infection are delineated and strategies for prophylaxis and treatment are given.

Outcome of prolapsed chorioamniotic membrane: relationship between the degree of herniation, infection, and pregnancy prolongation

Our objective was to determine the outcome predictor of conservative bed rest therapy for prolapsed chorioamniotic membrane. We could perform tocolysis for 61 women, 41 of visible membrane (group A) and 20 of protruding membrane (group B). The duration of pregnancy prolongation and gestational age (in weeks) at delivery in group A were significantly larger than in group B ( p < 0.05). Outcome of neonates was also significantly different between two groups ( p < 0.05). In 37 women of group A (90%) and 10 of group B (50%; group D), signs of infection were negative throughout the admission to delivery with conservative therapy (white blood cell counts </= 13000/microL and CRP values </= 1.0 mg/dL). In group D, pregnancy was prolonged 23.9 days, which was significantly longer than in group B ( p < 0.05). This study suggests that pregnancy prolongation for prolapsed membrane with conservative therapy depends on the success of prophylactic treatment for infection.

Changing obstetric practices associated with decreasing incidence of meconium aspiration syndrome

OBJECTIVE

To describe changes in neonatal and obstetric practices that may have contributed to the decreasing incidence of meconium aspiration syndrome in our population during this time.

METHODS

We compared neonatal and obstetric characteristics of 61 infants diagnosed with meconium aspiration syndrome with 1365 infants born through moderate or thick meconium-stained amniotic fluid at more than 37 weeks' completed gestation. Data were prospectively collected, and all respiratory diagnoses were concurrently made. Three distinct birth year groups were analyzed based on changing obstetric practice paradigms.

RESULTS

Meconium aspiration syndrome decreased nearly four-fold from 1990-1992 to 1997-1998 (5.8% to 1.5% of meconium-stained infants more than 37 weeks; P <.003). The only change in neonatal characteristics was a 33% decrease in births more than 41 weeks with a reciprocal 33% increase in births 38-39 weeks during 1997-1998. Significant changes in obstetric practice included more frequent diagnosis of nonreassuring fetal heart rate patterns, greater use of amnioinfusion, and increased cesarean delivery rate in 1997-1998. By logistic regression analysis, the only consistent risk factor for meconium aspiration syndrome across all three epochs was the presence of tracheal meconium.

CONCLUSION

Reduction in post-term delivery was the most important factor in reducing meconium aspiration syndrome.

Management of premature rupture of membranes

The management of patients with PROM, regardless of gestational age, remains controversial. Generally, when patients are in labor, have infection, or there is irreversible fetal distress, there are few options other than delivery. For those not in labor, especially in premature gestational ages, the complexities of the many combinations of decisions to be made regarding the best methods for evaluating patients, prolonging gestation, reducing complications of prematurity, and choosing the timing and route of delivery make studying and solving the problem of the best option for management difficult at best. The administration of corticosteroids and broad-spectrum antibiotics of those patients in the very early premature gestational age groups has now been shown clearly to improve outcome. Beyond that, the remainder of these problems are somewhat unresolved and several reasonable options often exist and are likely to remain so for some time to come.

[Effect of perinatal inflammation syndrome on lung maturation and development]

Despite improvement in neonatal care, the incidence of bronchopulmonary dysplasia has not decreased over the last decade. Moreover, chronic lung disease still occurs in very premature infants who do not require ventilatory support at birth. This review presents the growing body of epidemiological, experimental and clinical evidence suggesting that the occurrence of an inflammatory reaction triggered in utero or immediately after birth is associated with the subsequent development of chronic lung disease. However, stimulators of inflammation or specific proinflammatory cytokines may also have beneficial on lung maturation. How proinflammatory mediators interfere with lung maturation and alveolarization needs to be better understood in order to pave the way for new immunomodulatory strategies to prevent chronic lung disease in very preterm infants.

[Efferent methods in the therapy of puerperal and postoperative complications]

Ninety-six patients with chorioamnionitis in labor were treated. Clinical observations and laboratory findings demonstrated high efficiency of multiple-modality treatment including use of efferent methods: plasmapheresis, incubation of cell mass with antibiotics, and ultra-violet exposure of the blood.

[Premature rupture of fetal membranes at term: sequelae of conservative management. An analysis of a personal patient sample]

Few procedures are less standardised than the procedure in case of pre-labour rupture of the membranes at term (PROM). We propose that management should be reviewed regularly on the basis of one's own data and be modified accordingly if necessary. For the duration of three months we analysed 400 pregnancies retrospectively. Patients with PROM were observed expectantly for 24 hours. If there were no spontaneous uterine contractions, labour was induced, depending on the degree of cervical dilatation. 10 percent of the cases studied had PROM. Of these a high proportion of 73 percent were primigravida, likewise 73 percent had an unripe cervix. The average time between PROM and delivery was 27 h. 50 percent of the babies were born 24 h after PROM. If delivery occurred more than 24 h after PROM, the rate of caesarean section (15 vs. 30 percent), the rate of forceps deliveries (11 vs. 20 percent), the rate of amnionitis (16 vs. 35 percent) and the number of admissions to the newborn-ICU (16 vs. 25 percent) almost doubled. The patients were examined vaginally relatively often prior to delivery (up to 18 times, with a mean of 8 times). We therefore recommend active management 6-8 h after PROM, should there be no onset of spontaneous uterine contractions. This is particularly beneficial to primigravida with an unripe cervix.

Does amniotomy influence the prognosis of babies in cases with severe chorioamnionitis? Report of a twin pregnancy with varying outcome

We report our experience in a woman with a twin pregnancy. The patient suffered severe Escherichia coli chorioamnionitis and the outcomes were different between the two babies after birth. The first baby had only a mild infection, but the second suffered sepsis and subsequent perinatal death. These differences in outcome appeared to be due to amniotomy performed for the first baby after late labor stage I to augment uterus contractions. Removal of infectious amniotic fluid from the amniotic cavity might thus have prevented the spread of the chorioamnionitis. E. coli sometimes causes severe infection during pregnancy and the perinatal period. In this case, a large number of enteropathogenic E. coli (serotype O-6) was cultured from blood, stool, pharyngeal swab, gastric juice and puncture fluid from the thoracic cavity of the second baby. O-6 is classified an enterotoxigenic strain mainly causing diarrhea because of endotoxin released from bacteria. O-6 has not hitherto been reported as a cause of severe infection in chorioamnionitis and perinatal sepsis.

Prophylactic amnioinfusion in preganancies complicated by chorioamnionitis: a prospective randomized trial

The objective of this article is to prospectively investigate the efficacy of amnioinfusion as a means to reduce febrile morbidity in pregnancies complicated by chorioamnionitis. All laboring patients with a temperature > or =100.1 degrees F were approached for study participation. Exclusion criteria included amnionitis diagnosed at greater than 8 cm dilation, multiple gestation, placental abruption, or a nonreassuring fetal heart rate tracing. Consenting patients were randomized to receive antibiotics (ampicillin or penicillin with gentamicin) and acetaminophen with or without amnioinfusion. All patients received intrauterine pressure catheter placement. For study patients, normal saline at room temperature was infused at 10 mL/min for 60 min, then 3 mL/min until delivery. Postpartum endometritis was defined as a temperature = 100.4 degrees F accompanied by uterine tenderness more than 12 hr after delivery. Statistical analysis was performed using the Student's t-test for continuous data and Chi-square for discrete variables. Thirty-six patients were enrolled, and complete data were available for 34 patients (17 in each group). There were no differences between groups with respect to maternal age, gravidity, race, or gestational age. There were also no differences between groups in duration of rupture of membranes, temperature at randomization, interval from randomization to delivery, cesarean section rate, or umbilical cord arterial pH. The mean temperature at the time of delivery was 99.8+/-0.9 degrees F for the amnioinfusion group versus 100.5+/-1.0 degrees F for the control group (p=0.046). Three of 17 amnioinfusion patients and 3 of 17 control patients had postpartum endometritis. There was 1 neonatal infection in the treatment group and no neonatal infections among the control patients. Prophylactic amnioinfusion was associated with a decline in temperature at the time of delivery. No untoward effects from the amnioinfusion were identified.

Perinatal bacterial infection: an update

This article reviews the current trends in the evaluation and management of bacterial infection involving the uterus, placenta, membranes, amniotic fluid, and fetus occurring near the time of birth. The discussion includes information regarding risk, incidence, pathophysiology, bedside diagnosis, interventional options including antibiotics, corticosteroids, fetal monitoring, and delivery, and possible preventive measures which affect the outcome. The adequate evaluation and management of perinatal infection requires a team approach with obstetricians and pediatricians. Clinical screening is useful in developing the diagnosis, but amniotic fluid evaluation remains the proposed gold standard. The role of cytokines is becoming increasingly important, as is seen in the association of IL-6 with positive amniotic fluid cultures and periventricular leukomalacia. Prompt recognition and management of the pregnancy affected by infection can improve perinatal outcomes. A management protocol is presented to help structure the approach to suspected infection. Premature delivery due to perinatal infection may be preventable.

Intra-amniotic infection and premature rupture of the membranes

The outcome of fetuses and newborn infants often is linked to maternal complications. IAI and PROM are key risk factors for neonatal sepsis.

Chorioamnionitis and endometritis

Chorioamnionitis complicates 1% to 2% of all pregnancies and may affect 10% of women with certain risk factors. Intraamnionic infection may result in devastating morbidity for both the fetus and the mother. Also, chorioamnionitis is associated with higher cesarean section rates. As demonstrated earlier, endometritis is a common complication of cesarean delivery alone. Nevertheless, antibiotic prophylaxis has been shown to reduce postpartum morbidity. In the face of chorioamnionitis and a cesarean delivery, the risk of developing endometritis increases exponentially. However, if appropriate antibiotic therapy is instituted at the time of diagnosis, fetal and maternal outcomes improve dramatically. Similar to chorioamnionitis, endometritis is usually polymicrobial in nature. The preponderance of the organisms isolated are anaerobic. Established risk factors include operative delivery, prolonged ruptured fetal membranes, and prolonged labor. The diagnosis is based primarily on clinical examination with fever and the exclusion of other sources of extrapelvic infection. Once the diagnosis is established, appropriate empiric antibiotics are instituted. Antibiotic therapy should be continued until the patient is afebrile and asymptomatic for 24 to 36 hours. Over the past 20 years, the use of single-agent therapy in these serious infections has been shown to be safe as well as effective. Once successful therapy is completed, the patient is discharged home with no oral antibiotics.

[Premature rupture of fetal membranes: problems and obstetric management]

The treatment of a premature rupture of the foetal membrane (prom) has up to now been a subject of controversy. Depending on the stage of gestation, the prompt birth ensuing as a result of prom, involves the risk of immaturity of the child. Conservative waiting by contrast, exposes mother and child to a potential risk of infection. The retrospective study presented, summarises the strategies for treating prom used at the Cologne University Department of Obstetrics and Gynaecology during the period from 1984 to 1989, and attempts to develop from these data proposals for the treatment of prom. With an increase in latency of over 24 hours between prom and delivery, the maternal and neonatal rate of infection also increased significantly. An effective result of a prophylaxis with antibiotics could only be shown in the reduction of incidence of infection in the mother. An effect on the neonatal rate of infection could not be seen. Inducing prepartually lung-maturity with glucocorticoides or ambroxol resulted in a significant decrease of the RDS-rate in new born children up to the 34th week of gestation. Beyond the 34th week of gestation, this effect could not be found. Whereas after completion of the 37th week of gestation, the preferred treatment used by doctors is allowing the shortest possible time of latency between prom and delivery, the expected pulmonary immaturity before the 34th week of gestation has to be treated by prolonging the pregnancy and inducing pulmonary maturity under antibiotic prophylaxis and at the same time controlling infection.(ABSTRACT TRUNCATED AT 250 WORDS)

[The amnioinfusion therapy of saline solution for premature rupture of the membranes before 27 weeks' gestational age]

Saline solution amnioinfusion was performed for 12 cases of preterm PROM before 27 weeks gestational age complicated by oligohydramnios in order to suppress chorioamnionitis, prevent fetal pulmonary hypoplasia and delay delivery. The results were as follows. 1. The mean gestational ages at diagnosis of premature rupture of membranes and initiating saline solution amnioinfusion were 23.6 +/- 2.9 weeks and 24.9 +/- 1.5 weeks, respectively. The mean duration of saline solution amnioinfusion was 14.7 +/- 11.9 days. The mean gestational age at delivery was 27.2 +/- 1.7 weeks. The mean birth weight was 1,056 +/- 220g. 2. Saline solution amnioinfusion was effective in relieving oligohydramnios in all cases. No pulmonary hypoplasia was observed in the infants. 3. Clinically saline solution amnioinfusion was effective in suppressing chorioamnionitis in 9 cases out of 12. Histologically the picture of chorioamnionitis was revealed in 10 cases out of 12. no serious infection was observed in the infants. 4. Nine infants out of 12 survived. There were 2 IUFD and one neonatal death. The perinatal survival rate was 75%. 5. It is concluded from the above results that saline solution amnioinfusion is an effective treatment for preterm PROM before 27 weeks' gestational age.

Perinatal placental pathology

Examination of the placenta may be viewed as a diary of the pregnancy. Apart from its immediate diagnostic value, it can also broadly serve two purposes: 1) it provides a method of auditing antenatal clinical judgment by clinicopathologic correlation, and 2) it makes an important contribution in the context of unsolved clinical problems. The placenta's strategic location at the fetomaternal interphase mirrors disorders of both mother and fetus; however, "merged images" still cause some confusion, eg, villitis. This review summarizes recent areas of clinicopathologic correlation that have enhanced our understanding of placental function and the fetoplacental unit.

[Perinatal listeriosis--a case report]

Listeria monocytogenes, an uncommon perinatal infection in human, has been reported to be correlated with abortion, premature labor, intrauterine fetal sepsis, intrauterine fetal death and neonatal infections. Reported here was the first case of perinatal listeriosis complicated with Listeria monocytogenes chorioamnionitis at 33 weeks' gestation in Taiwan. The transabdominal amniocentesis in this particular case confirmed the diagnosis. An live premature male fetus was delivered by emergency cesarean section on the next day of hospitalization due to acute fetal distress. The acute ill baby developed signs of meningitis on the following day. Blood culture of Listeriosis monocytogenes indicated early onset neonatal listeriosis. Brain sonography showed hydrocephalus after a one-month period antibiotic treatment, he was lost to follow-up one month later. A review of the literature is presented to describe the clinical, epidemiological and pathological findings and to highlight their variable presentations and procedures for management. Thus it is of great importance for obstetricians to include listeriosis as a differential diagnosis in cases of fever of unknown origin during pregnancy. Promptly obtaining proper cultures and instituting appropriate antibiotics therapy is emphasized.

Management of preterm premature rupture of membranes

In conclusion, the suggested management for PROM follows two general principles. The first principle, which is accepted by most, consists of searching for a positive history of PROM, confirming PROM (by speculum examination, pooling, positive Nitrazine testing, and ferning), and obtaining cervical and vaginal cultures (for group B streptococcus/gonococcus and chlamydia). If free-flowing fluid from the cervix is seen, or if pooling is present, a sample should be sent for L-S and PG analysis. The cervix is assessed (for position, dilatation, and abnormalities), monitoring of maternal vital signs and fetal heart rate is done, white blood cell and differentials are obtained, and finally, immediate ultrasonogrpahy should be performed to document fetal position and viability, the number of fetuses, the amount of amniotic fluid, fetal anatomy, gestational age, and estimated weight. The other principle is a controversial one. It involves the use of amniocentesis for determination of fetal lung maturity and the presence of bacteria (if technically feasible); the use of a short course of tocolysis (terbutaline, 0.250 mg subcutaneously, or a similar medication for patient evaluation) if patient has contractions and all information is not yet available; the administration of steroids to accelerate fetal lung maturity; and finally, the administration of prophylactic antibiotics. In any event, delivery is indicated if there is clinical evidence of chorioamnionitis, as evidenced by maternal fever and tachycardia, tender uterus, fetal tachycardia, elevated white blood cell count with bands or left shift, and a positive Gram stain on examination of amniotic fluid. Antibiotic prophylaxis or treatment is only used if group B streptococcus or N. gonorrhea, or both, are present. Cesarean sections are reserved for obstetrical indications only. Furthermore, delivery is also indicated if there is evidence of lung maturity, fetal distress, active labor or advanced cervical dilatation (greater than or equal to 4 cm), PROM before the 20th to 22nd week of gestation, advanced gestational age of more than 36 weeks, or hemorrhage. In all circumstances, monitoring of the fetus with PROM is essential, with a nonstress test performed every other day to assess variable decelerations or a daily biophysical profile performed, as previously recommended. Even though no absolute recommendation exists as to the frequency of intrapartum testing, evaluation of the fetus with PROM should be done frequently, even on a daily basis.(ABSTRACT TRUNCATED AT 400 WORDS)

Transplacental passage of intravenous immunoglobulin in the last trimester of pregnancy

Immunoglobulin G was given intravenously (IVIgG) to pregnant women (27 to 36 weeks gestation) with signs of chorioamnionitis who were at risk for preterm delivery. Twenty-four patients received antibiotics alone (control group). Twenty-seven patients received the same antibiotics in combination with IVIgG, either 12 gm in 12 hours (low IVIgG dosage) or 24 gm on each of 5 consecutive days (high IVIgG dosage). Transplacental passage of IVIgG was shown to be a function of gestational age and of dose. Up to the thirty-second week of gestation, IgG infusions had no effect on IgG concentrations in cord sera. After that time, cord serum IgG levels were significantly higher in the high-dose group compared with the low-dose and control groups. All four subclasses of IgG, and two different antibodies present in the IVIgG preparation passed from the mother to the fetus. Thus the infused IgG mimicked the transplacental passage of endogenous IgG.

Premature rupture of the membranes. A review

Premature rupture of the membranes remains a significant problem area in obstetrics. When the fetal lung maturity is inadequate and there is no evidence of intrauterine infection, a delay in delivery is recommended. When fetal lung maturity is expected or documented, lengthy delays in delivery should be avoided. Assays for phosphatidylglycerol in amniotic fluid collected from the vagina are most helpful in determining the maturity status. Therapeutic agents to accelerate lung maturity, stop labor or prevent infections must be considered investigational when used during the latency phase of premature rupture of the membranes.