Premature rupture of membranes at 34 to 37 weeks' gestation: aggressive versus conservative management

Planned early birth versus expectant management for women with preterm prelabour rupture of membranes prior to 37 weeks' gestation for improving pregnancy outcome

BACKGROUND

Delivery after preterm prelabour rupture of the membranes (PPROM) may be initiated soon after PPROM or, alternatively, be delayed. It is unclear which strategy is most beneficial for mothers and their babies.

OBJECTIVES

To assess the effect of planned early birth compared with expectant management for pregnancies complicated with PPROM prior to 37 weeks' gestation.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (May 2009), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2009, Issue 1), MEDLINE (1996 to May 2009), EMBASE (1974 to May 2009), and reference lists of trials and other review articles.

SELECTION CRITERIA

Randomised controlled trials comparing expectant management with early delivery for women with PPROM prior to 37 weeks' gestation. We excluded quasi randomised trials.

DATA COLLECTION AND ANALYSIS

Two review authors independently evaluated trials for inclusion into the review and for methodological quality.

MAIN RESULTS

We included seven trials (690 women) in the review. We identified no difference in the primary outcomes of neonatal sepsis (risk ratio (RR) 1.33, 95% confidence interval (CI) 0.72 to 2.47) or respiratory distress (RR 0.98, 95% CI 0.74 to 1.29). Early delivery increased the incidence of caesarean section (RR 1.51, 95% CI 1.08 to 2.10). There was no difference in the overall perinatal mortality (RR 0.98, 95% CI 0.41 to 2.36), intrauterine deaths (RR 0.26, 95% CI 0.04 to 1.52) or neonatal deaths (RR 1.59, 95% CI 0.61 to 4.16) when comparing early delivery with expectant management. There was no significant difference in measures of neonatal morbidity, including cerebroventricular haemorrhage (RR 1.90 95% CI 0.52 to 6.92), necrotising enterocolitis (RR 0.58, 95% CI 0.08 to 4.08), or duration of neonatal hospitalisation (mean difference (MD) -0.33 days, 95% CI -1.06 to 0.40 days). In assessing maternal outcomes, we found that early delivery increased endometritis (RR 2.32, 95% CI 1.33 to 4.07), but that early delivery had no effect on chorioamnionitis (RR 0.44, 95% CI 0.17 to 1.14). There was a significant reduction of early delivery on the duration of maternal hospital stay (MD -1.13 days, 95% CI -1.75 to -0.51 days).

AUTHORS' CONCLUSIONS

There is insufficient evidence to guide clinical practice on the benefits and harms of immediate delivery compared with expectant management for women with PPROM. To date all of the clinical trials have had methodological weaknesses and have been underpowered to detect meaningful measures of infant and maternal morbidity.

Preterm premature rupture of membranes: clinical outcomes of late-preterm infants

OBJECTIVE

To determine gestational age-specific neonatal outcomes of late preterm infants delivered as a consequence of premature rupture of membranes (PROM).

METHODS

Retrospective cohort study of infants born to women delivered electively due to preterm PROM between 34(0/7) and 36(6/7) weeks of gestation. Neonatal outcomes were compared between those delivered at 34(0/7) to 34( 6/7) weeks, at 35(0/7) to 35(6/7) weeks, and at 36( 0/7) to 36(6/7) weeks.

RESULTS

192 infants were identified. The 34(0/7) to 34(6/7) week infants had significantly higher neonatal intensive care admission rate (72.5%) compared to those at 35( 0/7) to 35(6/7) weeks (22.8%) and at 36 to 36(6/7) weeks (17.8%) (P < .05). Neonatal respiratory distress syndrome was significantly higher at 34(0/7) to 34(6/7) weeks (35.4%) compared with 35(0/7) to 35(6/7) week and 36(0/7) to 36( 6/7) week infants (10.5% and 4.1%; P < .05). The longest hospitalization occurred in the 34(0/7) to 34(6/7) week infants (248.5 +/- 20.0 hours).

CONCLUSION

Substantial short-term morbidity occurred in late preterm infants. The greatest number of complications affected infants born at 34(0/7) to 34(6/7) weeks.

Intravenous oxytocin alone for cervical ripening and induction of labour

BACKGROUND

Oxytocin is the commonest induction agent used worldwide. It has been used alone, in combination with amniotomy or following cervical ripening with other pharmacological or non-pharmacological methods.

OBJECTIVES

To determine the effects of oxytocin alone for third trimester cervical ripening and induction of labour in comparison with other methods of induction of labour or placebo/no treatment.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2009) and bibliographies of relevant papers.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing intravenous oxytocin with placebo or no treatment, or with prostaglandins (vaginal or intracervical) for third trimester cervical ripening or labour induction.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility and carried out data extraction.

MAIN RESULTS

Sixty-one trials (12,819 women) are included.When oxytocin inductions were compared with expectant management, fewer women failed to deliver vaginally within 24 hours (8.4% versus 53.8%, risk ratio (RR) 0.16, 95% confidence interval (CI) 0.10 to 0.25). There was a significant increase in the number of women requiring epidural analgesia (RR 1.10, 95% CI 1.04 to 1.17). Fewer women were dissatisfied with oxytocin induction in the one trial reporting this outcome (5.9% versus 13.7%, RR 0.43, 95% CI 0.33 to 0.56).Compared with vaginal prostaglandins, oxytocin increased unsuccessful vaginal delivery within 24 hours in the two trials reporting this outcome (70% versus 21%, RR 3.33, 95% CI 1.61 to 6.89). There was a small increase in epidurals when oxytocin alone was used (RR 1.09, 95% CI 1.01 to 1.17).Most of the studies included women with ruptured membranes, and there was some evidence that vaginal prostaglandin increased infection in mothers (chorioamnionitis RR 0.66, 95% CI 0.47 to 0.92) and babies (use of antibiotics RR 0.68, 95% CI 0.53 to 0.87). These data should be interpreted cautiously as infection was not pre-specified in the original review protocol.When oxytocin was compared with intracervical prostaglandins, there was an increase in unsuccessful vaginal delivery within 24 hours (50.4% versus 34.6%, RR 1.47, 95% CI 1.10 to 1.96) and an increase in caesarean sections (19.1% versus 13.7%, RR 1.37, 95% CI 1.08 to 1.74) in the oxytocin group.

AUTHORS' CONCLUSIONS

Comparison of oxytocin with either intravaginal or intracervical PGE2 reveals that the prostaglandin agents probably increase the chances of achieving vaginal birth within 24 hours. Oxytocin induction may increase the rate of interventions in labour.A suggestion that for women with prelabour rupture of membranes induction with vaginal prostaglandin may increase risk of infection for mother and baby warrants further study.

A systematic review of intentional delivery in women with preterm prelabor rupture of membranes

OBJECTIVE

To evaluate the effect of intentional delivery versus expectant management in women with preterm prelabor rupture of membranes (PPROM).

METHODS

We searched electronic databases and trials registries, contacted experts, and checked reference lists of relevant studies. Studies were included if they were randomized controlled trials comparing intentional delivery versus expectant management after PPROM, the gestational age of participants was between 30 and 36 weeks, and the study reported one of several pre-determined outcomes.

RESULTS

Four studies were included in the meta-analysis. No difference was found between intentional delivery and expectant management in neonatal intensive care unit (NICU) length of stay (LOS) (weighted mean difference (WMD) -0.81 day, 95% confidence interval (CI) -1.66, 0.04), respiratory distress syndrome (risk difference (RD) -0.01, 95% CI -0.07, 0.06), and confirmed neonatal sepsis (RD -0.01, 95% CI -0.05, 0.04). One study found a significantly lower incidence of suspected neonatal sepsis among the intentional delivery group (RD -0.31, 95% CI -0.50, -0.12; number needed to treat (NNT) 3, 95% CI 2, 8). Maternal LOS was significantly shorter for the intentional delivery group (WMD -1.39 day, 95% CI -2.03, -0.75). There was a significant difference in the incidence of clinical chorioamnionitis favoring intentional delivery (RD -0.16, 95% CI -0.23, -0.10; NNT 6, 95% CI 5, 11). There was no significant difference in the incidence of other maternal outcomes, including cesarean section (RD 0.05, 95% CI -0.01, 0.11).

CONCLUSIONS

Intentional delivery may be favorable to expectant management for some maternal outcomes (chorioamnionitis and LOS). There is insufficient evidence to suggest that either strategy is beneficial or harmful for the baby. Large multicenter trials with primary neonatal outcomes are required to assess whether intentional delivery is associated with less neonatal morbidity.

Indications for delivery and short-term neonatal outcomes in late preterm as compared with term births

OBJECTIVE

The objective of the study was to evaluate the indications for late preterm birth and compare outcomes by gestational age among late preterm (34-36 weeks) and term (> or = 37 weeks) neonates at our institution.

STUDY DESIGN

This was a retrospective analysis of delivery indications and short-term neonatal outcomes in women who delivered at the University Hospital between January 1, 2005 and Dec. 31, 2006. Data were analyzed using chi(2), Student's t-test, analysis of variance, and post hoc Tukey tests.

RESULTS

One hundred forty-nine late preterm (n = 49 for 34, n = 50 for 35, n = 50 for 36 weeks) and 150 term infants (n = 50 for 37, n = 50 for 38, n = 50 for 39 weeks or longer) were evaluated. Differences among groups (ie, 34 vs 35 vs 36 vs 37, etc) as well as combinations of differences between 2 groups (ie, 34-36 weeks vs > or = 37 or > or = 38 weeks) were analyzed. Spontaneous labor and/or rupture of membranes were the most common indications for late preterm delivery (92%). Compared with term, late preterm infants had longer hospital stays (5 days vs 2.4 days; P < .001) and higher rates of neonatal intensive care unit (NICU) admissions (56% vs 4%; P < .001), feeding problems (36% vs 5%; P < .001), hyperbilirubinemia (25% vs 3%; P < .001), and respiratory complications (20% vs 5%; P < .001). Neonatal complications were minimal at 38 weeks or longer.

CONCLUSION

Rates of neonatal intensive care unit admission, length of stay, and neonatal morbidities are significantly higher in late preterm as compared with term births.

Cystic periventricular leukomalacia in preterm infants: an analysis of obstetric risk factors

OBJECTIVE

To identify obstetric risk factors and to elucidate the effect of prolonged rupture of the membranes on the development of cystic periventricular leukomalacia (PVL) in preterm infants.

METHODS

A retrospective case-control study of 95 preterm infants with the diagnosis of PVL and 245 healthy controls matched for gestational age. A total of 52 antenatal, intrapartum and neonatal characteristics were studied by univariate methods and logistic regression.

RESULTS

Preterm premature rupture of membranes (PPROM) (odds ratio 2.1 [95% CI 1.3-3.4], P=.003), gestational age at PPROM (P=.025), prolonged rupture of membranes (P<.0001), administration of tocolytic agents (1.8 [1.1-3.0], P=.019) and antibiotics (1.9 [1.2-3.1], P=.008) were associated with PVL. The use of tocolytic agents >24 h (P=.008), prolonged latency between the increase in maternal leukocyte count and birth (P=.034), spontaneous onset of labor (1.8 [1.0-2.9], P=.026), vaginal delivery (1.7 [1.1-2.8], P=.029) and male gender (1.5 [1.0-2.0], P=.04) were found more frequently in PVL cases. Preeclampsia (0.4 [0.1-0.9], P=.034), hypertension at booking (P=.009), sonographic IUGR (P=.020), abnormal blood flow of the umbilical artery (P=.032) and cesarean section without labor (0.5 [0.3-0.8], P=.006) were found less frequently. In logistic regression analysis, prolonged rupture of the membranes (P=.748), preeclampsia (P=.973), the use of antibiotics (P=.617) and beta-sympathomimetic tocolytic agents (P=.563) lost statistical significance, whereas birth weight (P=.036) became significant.

CONCLUSION

PPROM and prolonged rupture of the membranes may provoke adverse effects on the neurodevelopmental outcome of the preterm fetus. These findings may have implications on the obstetric management of PPROM beyond 30 weeks of gestation. Cesarean section without labor was less likely associated with the diagnosis of PVL.

Indications for induction of labour: a best-evidence review

BACKGROUND

Rates of labour induction are increasing.

OBJECTIVES

To review the evidence supporting indications for induction.

SEARCH STRATEGY

We listed indications for labour induction and then reviewed the evidence. We searched MEDLINE and the Cochrane Library between 1980 and April 2008 using several terms and combinations, including induction of labour, premature rupture of membranes, post-term pregnancy, preterm prelabour rupture of membranes (PROM), multiple gestation, suspected macrosomia, diabetes, gestational diabetes mellitus, cardiac disease, fetal anomalies, systemic lupus erythematosis, oligohydramnios, alloimmunization, rhesus disease, intrahepatic cholestasis of pregnancy (IHCP), and intrauterine growth restriction (IUGR). We performed a review of the literature supporting each indication.

SELECTION CRITERIA

We identified 1387 abstracts and reviewed 418 full text articles. We preferentially included high-quality systematic reviews or large randomised trials. Where no such studies existed, we included the best evidence available from smaller randomised trials and observational studies.

MAIN RESULTS

We included 34 full text articles. For each indication, we assigned levels of evidence and grades of recommendation based upon the GRADE system. Recommendations for induction of labour for post-term gestation, PROM at term, and premature rupture of membranes near term with pulmonary maturity are supported by the evidence. Induction for IUGR before term reduces intrauterine fetal death, but increases caesarean deliveries and neonatal deaths. Evidence is insufficient to support induction for women with insulin-requiring diabetes, twin gestation, fetal macrosomia, oligohydramnios, cholestasis of pregnancy, maternal cardiac disease and fetal gastroschisis.

AUTHORS' CONCLUSIONS

Research is needed to determine risks and benefits of induction for many commonly advocated clinical indications.

Uncultivated bacteria as etiologic agents of intra-amniotic inflammation leading to preterm birth

Intra-amniotic infection and inflammation are major causes of preterm birth (PTB). However, intra-amniotic inflammation is often detected in the absence of infection. This may partly be due to the culturing methods employed in hospital laboratories, which are unable to detect the uncultivated species. In this study, intra-amniotic microbial infections associated with PTB were examined by both culture and 16S rRNA-based culture-independent methods and were corroborated by the presence of intra-amniotic inflammation. Amniotic fluid (AF) specimens from 46 pregnancies complicated by PTB and 16 asymptomatic women were analyzed. No bacterial DNA was amplified in AF collected from the asymptomatic women. Among the 46 samples associated with PTB, bacterial DNA was amplified from all (16/16) of the culture-positive samples and 17% (5/30) of the culture-negative samples. In the culture-positive group, additional species were detected in more than half (9/16) of the cases by PCR and clone analysis. Altogether, approximately two- thirds of the species detected by the culture-independent methods were not isolated by culture. They included both uncultivated and difficult-to-cultivate species, such as Fusobacterium nucleatum, Leptotrichia (Sneathia) spp., a Bergeyella sp., a Peptostreptococcus sp., Bacteroides spp., and a species of the order Clostridiales. To examine intra-amniotic inflammation, an AF proteomic fingerprint (mass-restricted score) was determined by surface-enhanced laser desorption ionization-time-of-flight mass spectrometry. Inflammation was detected in all five samples which were culture negative but PCR positive. Women who were PCR positive more often had elevated interleukin-6 levels in their AF, histological chorioamnionitis, and funisitis and delivered neonates with early-onset neonatal sepsis. Previously unrecognized, uncultivated, or difficult-to-cultivate species may play a key role in the initiation of PTB.

Fetal heart rate monitoring patterns in women with amniotic fluid proteomic profiles indicative of inflammation

We hypothesized that abnormal fetal heart rate monitoring patterns (FHR-MPs) occur more often in pregnancies complicated by intra-amniotic inflammation. Therefore, our objective was to examine the relationships among FHR-MP abnormalities, intra-amniotic inflammation and/or infection, acute histological chorioamnionitis, and early-onset neonatal sepsis (EONS) in pregnancies complicated by preterm birth. Additionally, the ability of various FHR-MPs to predict EONS was investigated. FHR-MPs from 87 singleton premature neonates delivered within 48 hours from amniocentesis (gestational age, mean +/- SD: 28.9 +/- 3.3 weeks) were analyzed blindly using strict National Institute of Child Health and Human Development criteria. Strips were evaluated at three time points: at admission, at amniocentesis, and prior to delivery. Intra-amniotic inflammation was established based on a previously validated proteomic fingerprint (mass-restricted score). Diagnoses of histological chorioamnionitis and EONS were based on well-recognized pathological, clinical, and laboratory criteria. We determined that fetuses of women with severe intra-amniotic inflammation had a higher FHR baseline throughout the entire monitoring period and an increased frequency of a nonreactive FHR-MP at admission. Of all FHR-MPs, a nonreassuring test at admission had 32% sensitivity, 95% specificity, 73% positive predictive value, 77% negative predictive value, and 76% accuracy in predicting EONS. Although a nonreassuring FHR-MP at admission was significantly associated with EONS after correcting for gestational age (odds ratio, 5.6; 95% confidence interval, 1.2 to 26.2; P = 0.030), the majority of the neonates that developed EONS had an overall reassuring FHR-MP. Nonreassuring FHR-MPs at either amniocentesis or delivery had no association with EONS. We conclude that in cases complicated by preterm birth, a nonreassuring FHR-MP at the initial evaluation is a specific but not a sensitive predictor of EONS. An abnormal FHR-MP can thus raise the level of awareness that a fetus with EONS may be born, but it is not a useful clinical indicator of the need for antibiotic treatment of the neonate.

The influence of obstetric practices on late prematurity

In this article, the authors review the standard management of several maternal and fetal complications of pregnancy and examine the effect these practices may have on the late preterm birth rate. Given the increasing rate of late preterm birth and the increased recognition of the morbidity and mortality associated with delivery between 34 and 37 weeks, standard obstetric practices and practice patterns leading to late preterm birth should be critically evaluated. The possibility of expectant management of some pregnancy complications in the late preterm period should be investigated. Furthermore, prospective research is warranted to investigate the role of antenatal corticosteroids beyond 34 weeks.

Late preterm infants, early term infants, and timing of elective deliveries

Delivery of infants who are physiologically mature and capable of successful transition to the extrauterine environment is an important priority for obstetric practitioner. A corollary of this goal is to avoid iatrogenic complications of prematurity and maternal complications from delivery. The purpose of this review is to describe the consequences of birth before physiologic maturity in late preterm and term infants, to identify factors contributing to the decline in gestational age of deliveries in the United States, and to describe strategies to reduce premature delivery of late preterm and early term infants.

Multidimensional proteomics analysis of amniotic fluid to provide insight into the mechanisms of idiopathic preterm birth

Background

Though recent advancement in proteomics has provided a novel perspective on several distinct pathogenetic mechanisms leading to preterm birth (inflammation, bleeding), the etiology of most preterm births still remains elusive. We conducted a multidimensional proteomic analysis of the amniotic fluid to identify pathways related to preterm birth in the absence of inflammation or bleeding.

Methodology/Principal Findings

A proteomic fingerprint was generated from fresh amniotic fluid using surface-enhanced laser desorbtion ionization time of flight (SELDI-TOF) mass spectrometry in a total of 286 consecutive samples retrieved from women who presented with signs or symptoms of preterm labor or preterm premature rupture of the membranes. Inflammation and/or bleeding proteomic patterns were detected in 32% (92/286) of the SELDI tracings. In the remaining tracings, a hierarchical algorithm was applied based on descriptors quantifying similarity/dissimilarity among proteomic fingerprints. This allowed identification of a novel profile (Q-profile) based on the presence of 5 SELDI peaks in the 10–12.5 kDa mass area. Women displaying the Q-profile (mean±SD, gestational age: 25±4 weeks, n = 40) were more likely to deliver preterm despite expectant management in the context of intact membranes and normal amniotic fluid clinical results. Utilizing identification-centered proteomics techniques (fluorescence two-dimensional differential gel electrophoresis, robotic tryptic digestion and mass spectrometry) coupled with Protein ANalysis THrough Evolutionary Relationships (PANTHER) ontological classifications, we determined that in amniotic fluids with Q-profile the differentially expressed proteins are primarily involved in non-inflammatory biological processes such as protein metabolism, signal transduction and transport.

Conclusion/Significance

Proteomic profiling of amniotic fluid coupled with non-hierarchical bioinformatics algorithms identified a subgroup of patients at risk for preterm birth in the absence of intra-amniotic inflammation or bleeding, suggesting a novel pathogenetic pathway leading to preterm birth. The altered proteins may offer opportunities for therapeutical intervention and future drug development to prevent prematurity.

Nucleated red blood cells are a direct response to mediators of inflammation in newborns with early-onset neonatal sepsis

OBJECTIVE

The objective of the study was to test the hypothesis that inflammation modulates fetal erythroblastosis and/or the release of nucleated red blood cells (NRBCs) independent of hypoxia or fetal stress. We sought to determine whether fetal inflammation is associated with an elevation in neonatal NRBC count in the setting of inflammation-associated preterm birth.

STUDY DESIGN

The relationships between peripheral NRBC count, histological chorioamnionitis, umbilical cord interleukin (IL)-6, erythropoietin (EPO), cortisol, and acid-base status were analyzed in 68 preterm singletons, born to mothers who had an amniocentesis to rule out infection. Proteomic profiling of amniotic fluid identified presence of intraamniotic inflammation according to established parameters. NRBC counts were assessed within 1 hour of birth. Early-onset neonatal sepsis (EONS) was established based on hematological and microbiological indices. IL-6, EPO, and cortisol levels were measured by immunoassays. Fetal acid-base status was determined within 10 minutes of delivery. Parametric or nonparametric statistics were used.

RESULTS

Fetuses with EONS (n = 19) were delivered at earlier gestational ages (mean +/- SD: 27.1 +/- 2.8 weeks, P = .001) and more often by mothers with intraamniotic inflammation (P = .022) and histological chorioamnionitis (P < .001). Neonates with EONS had higher absolute NRBC counts (P = .011). NRBC counts were directly correlated with cord blood IL-6 levels (P < .001) but not with EPO, cortisol or parameters of acid-base status levels regardless of EONS status. These relationships remained following correction for gestational age, diabetes, intrauterine growth restriction, and steroid exposure.

CONCLUSION

In the setting of inflammation-associated preterm birth and in the absence of hypoxia, elevations in NRBCs in the early neonatal period may be a direct response of exposure to inflammatory mediators in utero.

Using proteomic analysis of the human amniotic fluid to identify histologic chorioamnionitis

OBJECTIVE

To estimate the relationship between histologic chorioamnionitis and four amniotic fluid proteomic biomarkers characteristic of inflammation (defensins 2 and 1, calgranulins C and A).

METHODS

One hundred fifty-eight women with singleton pregnancies had a clinically indicated amniocentesis to rule out inflammation and infection in the context of preterm labor or preterm premature rupture of membranes. A proteomic fingerprint (Mass Restricted score) was generated from amniotic fluid using surface-enhanced laser desorption ionization time-of-flight mass spectrometry. The Mass Restricted score ranges from 0 to 4 (none to all four biomarkers present) in direct relationship with severity of intra-amniotic inflammation. Presence or absence of biomarkers was analyzed in relationship to placental pathology. Criteria for severity of histologic chorioamnionitis were 3 stages and 4 grades of inflammation of the amnion, choriodecidua and chorionic plate.

RESULTS

The prevalence of histologic chorioamnionitis was 64% (stage I 12%, stage II 16%, and stage III 37%). The Mass Restricted score significantly correlated with stages of histologic chorioamnionitis (r=0.539, P<.001), grades of choriodeciduitis (r=0.465, P<.001), and amnionitis (r=0.536, P<.001). African-American women were overrepresented in the group with severe inflammation (Mass Restricted score 3-4, P=.022). Of the four biomarkers of the Mass Restricted score, calgranulin C had the strongest relationship with presence of stage III chorioamnionitis, independent of race, amniocentesis-to-delivery interval, and gestational age.

CONCLUSION

Proteomic analysis of amniotic fluid provides an opportunity for early recognition of histologic chorioamnionitis. This methodology may in the future identify candidates for antenatal therapeutic interventions.

LEVEL OF EVIDENCE

II.

Neonatal mortality and morbidity rates in late preterm births compared with births at term

OBJECTIVE

To analyze neonatal mortality and morbidity rates at 34, 35, and 36 weeks of gestation compared with births at term over the past 18 years at our hospital and to estimate the magnitude of increased risk associated with late preterm births compared with births later in gestation.

METHODS

We performed a retrospective cohort study of births at our hospital over the past 18 years. The study included all liveborn singleton infants between 34 and 40 weeks of gestation and without anomalies that were delivered to women who received prenatal care in our hospital system. Neonatal outcomes for late preterm births were compared with those for infants delivered at 39 weeks.

RESULTS

Late preterm singleton live births constituted approximately 9% of all deliveries at our hospital and accounted for 76% of all preterm births. Late preterm neonatal mortality rates per 1,000 live births were 1.1, 1.5, and 0.5 at 34, 35, and 36 weeks, respectively, compared with 0.2 at 39 weeks (P<.001). Neonatal morbidity was significantly increased at 34, 35, and 36 weeks, including ventilator-treated respiratory distress, transient tachypnea, grades 1 or 2 intraventricular hemorrhage, sepsis work-ups, culture-proven sepsis, phototherapy for hyperbilirubinemia, and intubation in the delivery room. Approximately 80% of late preterm births were attributed to idiopathic preterm labor or ruptured membranes and 20% to obstetric complications.

CONCLUSION

Late preterm births are common and associated with significantly increased neonatal mortality and morbidity compared with births at 39 weeks. Preterm labor was the most common cause (45%) for late preterm births.

LEVEL OF EVIDENCE

II.

Induction of labour versus expectant management in women with preterm prelabour rupture of membranes between 34 and 37 weeks (the PPROMEXIL-trial)

BACKGROUND

Preterm prelabour rupture of the membranes (PPROM) is an important clinical problem and a dilemma for the gynaecologist. On the one hand, awaiting spontaneous labour increases the probability of infectious disease for both mother and child, whereas on the other hand induction of labour leads to preterm birth with an increase in neonatal morbidity (e.g., respiratory distress syndrome (RDS)) and a possible rise in the number of instrumental deliveries.

METHODS/DESIGN

We aim to determine the effectiveness and cost-effectiveness of immediate delivery after PPROM in near term gestation compared to expectant management. Pregnant women with preterm prelabour rupture of the membranes at a gestational age from 34+0 weeks until 37+0 weeks will be included in a multicentre prospective randomised controlled trial. We will compare early delivery with expectant monitoring. The primary outcome of this study is neonatal sepsis. Secondary outcome measures are maternal morbidity (chorioamnionitis, puerperal sepsis) and neonatal disease, instrumental delivery rate, maternal quality of life, maternal preferences and costs. We anticipate that a reduction of neonatal infection from 7.5% to 2.5% after induction will outweigh an increase in RDS and additional costs due to admission of the child due to prematurity. Under these assumptions, we aim to randomly allocate 520 women to two groups of 260 women each. Analysis will be by intention to treat. Additionally a cost-effectiveness analysis will be performed to evaluate if the cost related to early delivery will outweigh those of expectant management. Long term outcomes will be evaluated using modelling.

DISCUSSION

This trial will provide evidence as to whether induction of labour after preterm prelabour rupture of membranes is an effective and cost-effective strategy to reduce the risk of neonatal sepsis. CONTROLLED CLINICAL TRIAL REGISTER: ISRCTN29313500.

Proteomic biomarkers of intra-amniotic inflammation: relationship with funisitis and early-onset sepsis in the premature neonate

Our goal was to determine the relationship between 4 amniotic fluid (AF) proteomic biomarkers (human neutrophil defensins 2 and 1, calgranulins C and A) characteristic of intra-amniotic inflammation, and funisitis and early-onset sepsis in premature neonates. The mass restricted (MR) score was generated from AF obtained from women in preterm labor (n = 123). The MR score ranged from 0-4 (none to all biomarkers present). Funisitis was graded histologically and interpreted in relation to the MR scores. Neonates (n = 97) were evaluated for early-onset sepsis. There was significant correlation between the severity of AF inflammation and the presence (53/123) and grades of funisitis (p < 0.001). Funisitis occurred independently of the amniocentesis-to-delivery interval or status of the membranes and was best predicted by an MR score 3-4 and an earlier gestational age (GA) at delivery. Neonates born to women with an MR score 3-4 had an increased incidence of suspected/confirmed sepsis, even after adjusting for GA at birth. Calgranulin C had the highest association with clinically significant funisitis, while calgranulin A had the strongest association with early-onset sepsis. To conclude, AF proteomic analysis shows that women with MR scores 3-4 are more likely to have histologic funisitis, and deliver neonates with early-onset sepsis.

Proteomic profiling of the amniotic fluid to detect inflammation, infection, and neonatal sepsis

BACKGROUND

Proteomic analysis of amniotic fluid shows the presence of biomarkers characteristic of intrauterine inflammation. We sought to validate prospectively the clinical utility of one such proteomic profile, the Mass Restricted (MR) score.

METHODS AND FINDINGS

We enrolled 169 consecutive women with singleton pregnancies admitted with preterm labor or preterm premature rupture of membranes. All women had a clinically indicated amniocentesis to rule out intra-amniotic infection. A proteomic fingerprint (MR score) was generated from fresh samples of amniotic fluid using surface-enhanced laser desorption ionization (SELDI) mass spectrometry. Presence or absence of the biomarkers of the MR score was interpreted in relationship to the amniocentesis-to-delivery interval, placental inflammation, and early-onset neonatal sepsis for all neonates admitted to the Newborn Special Care Unit (n = 104). Women with "severe" amniotic fluid inflammation (MR score of 3 or 4) had shorter amniocentesis-to-delivery intervals than women with "no" (MR score of 0) inflammation or even "minimal" (MR score of 1 or 2) inflammation (median [range] MR 3-4: 0.4 d [0.0-49.6 d] versus MR 1-2: 3.8 d [0.0-151.2 d] versus MR 0: 17.0 d [0.1-94.3 d], p < 0.001). Nonetheless, a "minimal" degree of inflammation was also associated with preterm birth regardless of membrane status. There was a significant association between the MR score and severity of histological chorioamnionitis (r = 0.599, p < 0.001). Furthermore, neonatal hematological indices and early-onset sepsis significantly correlated with the MR score even after adjusting for gestational age at birth (OR for MR 3-4: 3.3 [95% CI, 1.1 to 9.2], p = 0.03). When compared with other laboratory tests routinely used to diagnose amniotic fluid inflammation and infection, the MR score had the highest accuracy to detect inflammation (white blood cell count > 100 cells/mm3), whereas the combination of Gram stain and MR score was best for rapid prediction of intra-amniotic infection (positive amniotic fluid culture).

CONCLUSIONS

High MR scores are associated with preterm delivery, histological chorioamnionitis, and early-onset neonatal sepsis. In this study, proteomic analysis of amniotic fluid was shown to be the most accurate test for diagnosis of intra-amniotic inflammation, whereas addition of the MR score to the Gram stain provides the best combination of tests to rapidly predict infection.

Late preterm gestation: physiology of labor and implications for delivery

The late preterm infant represents a significant portion of preterm deliveries. Historically, this cohort has been referred to as near-term, which may not address adequately the increased perinatal morbidity these neonates experience. The changing demographics of pregnant women also are increasing the number of inductions in this gestational age group. More women with chronic hypertension, diabetes, and other chronic medical problems are getting pregnant, and often these pregnancies may require induction during this gestational age. The increasing numbers of multi-fetal gestations also have an average gestational age at delivery in this range of 34 to 36.6 weeks. Preeclampsia is another factor that can lead to delivery and induction during this gestational age. This article discusses some of the physiologic causes behind late preterm deliveries.

Neonatal mortality and morbidity after aggressive long-term tocolysis for preterm premature rupture of the membranes

OBJECTIVE

To test the hypothesis that predischarge morbidity and mortality are not increased for infants admitted to our neonatal intensive care unit and whose mothers had tocolysis for >48 h plus antibiotics and steroids (aggressive long-term tocolysis) after preterm premature rupture of the membranes (PPROM) as compared with gestational age-matched infants born to mothers not treated for PPROM.

METHODS

A retrospective cohort study was conducted on live preterm births (<or=36.0 weeks) admitted to the neonatal intensive care unit between January 1, 1999 and June 30, 2003, comparing singletons born to mothers with PPROM+tocolysis for >48 h (n=137, group 1) with singletons born to all other mothers matched for group-1 gestational age at delivery (n=628, group 2), excluding severe maternal complications such as insulin-dependent diabetes and preeclampsia in both groups. Primary outcome was the predischarge mortality and morbidity of the neonates.

RESULTS

In the group with post-PPROM tocolysis which lasted for 14.4+/-14.0 days with a latency of 15.3+/-15.3 days (time from PPROM to delivery) and 14.4+/-14.0 days (time from the start of tocolysis to delivery), the predischarge mortality and morbidity was not increased compared to the non-treated group. The 1- and 10-min Apgar scores of between 1 and 7 were less frequent with tocolysis (p<0.05), and oxygen use was less frequent (26.3 vs. 36.3%, p=0.03) and shorter (8.7 vs. 19.6 days, p=0.03). However, amniotic fluid infection syndrome and latency (i.e. >1 week) are the most potential predictors of the respiratory distress syndrome in addition to gestational age at delivery in pregnancies with post-PPROM tocolysis.

CONCLUSIONS

Amniotic fluid infection syndrome and a latency of >1 week achieved by aggressive post-PPROM tocolysis lessens the advantages of extended gestational age and decreased predischarge neonatal morbidity. These findings may have important implications for the clinical management of PPROM.

Spontaneous preterm labor and premature rupture of membranes at late preterm gestations: to deliver or not to deliver

Nationwide the American College of Obstetricians and Gynecologists noted in 1995 that the survival rate for newborns at 34 weeks is within 1% of those born at or beyond 37 weeks. Newborn major morbidity is slightly but significantly increased from 34(0) to 36(6) compared with 37 or greater weeks. These data form the basis for and reflect the perinatal outcomes associated with the standardized obstetric practices of effecting delivery for women with amnion rupture and also of not attempting tocolysis for preterm labor at or beyond 34(0) weeks gestation. Pragmatically, a prospective randomized management trial of women at late preterm gestation (34(0) to 36(6)) and with spontaneous preterm labor or amnion rupture would require multi-institutional support to achieve a required study population.

Protocol for the immediate delivery versus expectant care of women with preterm prelabour rupture of the membranes close to term (PPROMT) Trial [ISRCTN44485060]

Background

Preterm prelabour rupture of membranes (PPROM) complicates up to 2% of all pregnancies and is the cause of 40% of all preterm births. The optimal management of women with PPROM prior to 37 weeks, is not known. Furthermore, diversity in current clinical practice suggests uncertainty about the appropriate clinical management.

There are two options for managing PPROM, expectant management (a wait and see approach) or early planned birth. Infection is the main risk for women in which management is expectant. This risk need to be balanced against the risk of iatrogenic prematurity if early delivery is planned. The different treatment options may also have different health care costs. Expectant management results in prolonged antenatal hospitalisation while planned early delivery may necessitate intensive care of the neonate for problems associated with prematurity.

Methods/Design

We aim to evaluate the effectiveness of early planned birth compared with expectant management for women with PPROM between 34 weeks and 36⁶ weeks gestation, in a randomised controlled trial. A secondary aim is a cost analysis to establish the economic impact of the two treatment options and establish the treatment preferences of women with PPROM close to term.

The early planned birth group will be delivered within 24 hours according to local management protocols. In the expectant management group birth will occur after spontaneous labour, at term or when the attending clinician feels that birth is indicated according to usual care. Approximately 1812 women with PPROM at 34–36⁶ weeks gestation will be recruited for the trial.

The primary outcome of the study is neonatal sepsis. Secondary infant outcomes include respiratory distress, perinatal mortality, neonatal intensive care unit admission, assisted ventilation and early infant development. Secondary maternal outcomes include chorioamnionitis, postpartum infection treated with antibiotics, antepartum haemorrhage, induction of labour, mode of delivery, maternal satisfaction with care, duration of hospitalisation, and maternal wellbeing at four months postpartum.

Discussion

This trial will provide evidence on the optimal care for women with PPROM close to term (34–37 weeks gestation). Consideration of both the clinical and economic sequelae of the management of PPROM will enable informed decision making and guideline development.

Preterm prelabour rupture of the membranes: a survey of current practice

BACKGROUND

Preterm prelabour rupture of the membranes (PPROM) complicates 1-2% of all pregnancies. Risks of remaining in utero need to be balanced against the risks of iatrogenic prematurity if early birth is planned.

AIMS

To assess and further define the current management of women with pregnancies complicated with PPROM in Australia.

METHODS

A mail out questionnaire was sent to all Australian Members and Fellows of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG).

RESULTS

There were 731 responses from RANZCOG Fellows and Members. Corticosteroids were used routinely in the setting of PPROM by 99% (95% confidence intervals (CI) 98.4-100.0%) of obstetricians. Tocolysis was used commonly by 75% (95% CI 98.4-100.0%). Antibiotics are also used routinely by 63% (95% CI 58.8-67.3%) of Australian obstetricians. For women presenting with PPROM less than 34 weeks' gestation 56% (95% CI 48.1-60.0%) of obstetricians would plan to deliver these women prior to term, while for women presenting with PPROM greater than 34 weeks' gestation 50% (95% CI 46.0-54.8%) would offer delivery to such women prior to term.

CONCLUSIONS

There is significant variation in clinical practice in the management of women who present with PPROM in Australia. There is little consensus regarding the optimal timing of delivery for babies of women with pregnancies complicated with PPROM. The present survey supports the need and feasibility of a randomised controlled trial to assess the appropriate gestation at which to deliver women with PPROM near to term.

Preterm premature rupture of the membranes: current approaches to evaluation and management

Preterm premature rupture of the membranes (PROM) complicates 3% of pregnancies and is responsible for approximately one third of all preterm births. Because preterm PROM presents a clinical situation where early delivery is to be anticipated and prenatal and neonatal complications are common, the physician caring for women with this common obstetric complication has an opportunity to intervene in a manner that can improve perinatal outcome. This article addresses clinically relevant questions regarding the evaluation and management of preterm PROM.

Morbidité néonatale après attitude d'expectative suivie d'une naissance systématique à 34 semaines d'aménorrhée en situation de rupture prématurée des membranes

OBJECTIVE

To evaluate the neonatal morbidity and its risks factors in case of uncomplicated preterm rupture of membranes managed conservatively with subsequent planned delivery at 34 weeks of gestation.

PATIENTS AND METHODS

We studied retrospectively 42 consecutive neonates systematically delivered at 34 weeks of gestation after more than 48 hours of conservative management for uncomplicated preterm rupture of membranes. Conservative management was conducted in a single tertiary care center and consisted in corticotherapy and in antibiotherapy (amoxycilline during 7 days). We evaluated the neonatal mortality rate, the incidence of infection, respiratory distress, neurological disorders, and we looked for their prenatal risks factors.

RESULTS

Forty-two neonates were included. The median gestational age at rupture was 31.1 weeks of gestation (from 25 to 33.9 weeks). The median duration of expectant management was 20 days (from 2.4 to 65 days). We observed 7 cases of neonatal infection but no septic failure, 18 cases of respiratory distresses among which 9 required a tracheal intubation for a mean duration of 3.7 days, no perinatal encephalopathy (5 cases of subependymal haemorrhage) and no neonatal death. We isolated one single risk factor that was the lowest gestational age at rupture in case of subsequent respiratory distress (29.6 vs 31.9 weeks; P=0.02).

DISCUSSION AND CONCLUSION

Neonatal morbidity in this population consisted mainly in respiratory distresses with an increased incidence when gestational age at rupture decreased.

Prevalence, Management, and Outcomes of Preterm Prelabour Rupture of the Membranes of Women in Canada

OBJECTIVES

To determine the prevalence of preterm prelabour rupture of the membranes (PPROM) at Canadian university-affiliated perinatal referral centres, to assess the different management strategies, and to review neonatal outcomes.

METHODS

Twelve Canadian university-affiliated perinatal referral centres provided information on their management of PPROM, and 9 participated in data collection to determine prevalence. All women presenting with PPROM during a 2-week period were observed until delivery, and obstetric and neonatal outcome data were subsequently obtained. The total number of deliveries in each centre was recorded for the same time period. We also determined the incidence of PPROM and the neonatal outcome for all women presenting with PPROM at the Kingston General Hospital from January 1999 to December 2001 by retrospective chart review.

RESULTS

In the 9 academic centres, 27 women (1 with a twin pregnancy) presented with PPROM during the 2-week period. There were 1168 deliveries during the same time period, giving a prevalence of PPROM of 2.3%. Overall, 53% of placentas submitted for histopathology after PPROM demonstrated evidence of chorioamnionitis. In the retrospective chart review, we found 153 cases of confirmed PPROM from January 1999 to December 2001,an incidence of 2.8%. Clinical management in all centres was similar for most women who presented with PPROM prior to 34 weeks' gestation. Management after 34 weeks' gestation varied among the 12 centres, ranging from immediate induction of labour to expectant management and induction at a greater gestational age (GA).

CONCLUSIONS

The increased neonatal morbidity associated with PPROM appears to be inversely related to GA. Increased risk of chorioamnionitis is related to increased time from PPROM to delivery.

Preterm premature rupture of membranes: diagnosis, evaluation and management strategies

Preterm premature rupture of the membranes (PPROM) is responsible for one-third of all preterm births and affects 120,000 pregnancies in the United States each year. Effective treatment relies on accurate diagnosis and is gestational age dependent. The diagnosis of PPROM is made by a combination of clinical suspicion, patient history and some simple tests. PPROM is associated with significant maternal and neonatal morbidity and mortality from infection, umbilical cord compression, placental abruption and preterm birth. Subclinical intrauterine infection has been implicated as a major aetiological factor in the pathogenesis and subsequent maternal and neonatal morbidity associated with PPROM. The frequency of positive cultures obtained by transabdominal amniocentesis at the time of presentation with PPROM in the absence of labour is 25-40%. The majority of amniotic fluid infection in the setting of PPROM does not produce the signs and symptoms traditionally used as diagnostic criteria for clinical chorioamnionitis. Any evidence of infection by amniocentesis should be considered carefully as an indication for delivery. Documentation of amniotic fluid infection in women who present with PPROM enables us to triage our therapeutic decision making rationally. In PPROM, the optimal interval for delivery occurs when the risks of immaturity are outweighed by the risks of pregnancy prolongation (infection, abruption and cord accident). Lung maturity assessment may be a useful guide when planning delivery in the 32- to 34-week interval. A gestational age approach to therapy is important and should be adjusted for each hospital's neonatal intensive care unit. Antenatal antibiotics and corticosteroid therapies have clear benefits and should be offered to all women without contraindications. During conservative management, women should be monitored closely for placental abruption, infection, labour and a non-reassuring fetal status. Women with PPROM after 32 weeks of gestation should be considered for delivery, and after 34 weeks the benefits of delivery clearly outweigh the risks.

Preterm Premature Rupture of Membranes: Is There an Optimal Gestational Age for Delivery?

OBJECTIVE

To characterize neonatal and maternal morbidity and mortality rates in pregnancies complicated by preterm premature rupture of membranes (PROM) and determine whether there is an optimal delivery gestational age.

METHODS

We reviewed maternal and neonatal outcomes of women with PROM 24 weeks or more that resulted in delivery at less than 37 weeks at our institution from August 1998 to August 2000. Standardized management included the use of antibiotics, betamethasone at less than 32 weeks, and expectant management until 24 weeks or more. Outcomes evaluated included neonatal mortality, composite major and minor neonatal morbidity, individual major and minor neonatal morbidity rates, maternal infection morbidity, and maternal and neonatal length of stay. Gestational age-specific maternal and neonatal outcomes were compared with a referent group of pregnancies complicated by preterm PROM that delivered between 36 0/7 and 36 6/7 weeks of gestation.

RESULTS

During the study interval, 430 women with preterm PROM were identified. Composite major neonatal morbidity was significantly higher among pregnancies delivered at 33 weeks of gestation or less after preterm PROM as compared with those who delivered at 36 weeks. Composite neonatal minor morbidity was significantly higher among pregnancies delivered at 34 weeks or less after preterm PROM as compared with those who delivered at 36 weeks. However, there was no improvement in the composite major and minor neonatal morbidity rates for those pregnancies delivered beyond 34 weeks of gestation. Both maternal and infant length of stay were significantly longer for cases of preterm PROM delivered at 34 weeks or less as compared with those who delivered at 36 weeks.

CONCLUSION

Our findings suggest that expectant management of women at 34 weeks and beyond is of limited benefit.

Preterm premature rupture of the membranes: diagnosis and management

Preterm premature rupture of the membranes (preterm PROM) is a common and significant cause of preterm birth and perinatal morbidity and mortality. The obstetric caregiver has the opportunity significantly to alter pregnancy and perinatal outcome for women suffering from this complication. Although management is often predetermined by the presence of clinical infection, vaginal bleeding, labor, or nonreassuring fetal heart-rate pattern on admission, a gestational age-based approach to the management of the stable patient with preterm PROM offers the potential to reduce perinatal infectious and gestational age-dependent morbidity for patients who are amenable to conservative management.

Contemporary management of preterm premature rupture of membranes (PPROM): a survey of maternal-fetal medicine providers

OBJECTIVE

This study was undertaken to characterize variations in the management for women with preterm premature rupture of membranes (PPROM) among maternal-fetal medicine (MFM) specialists in the context of current recommendations for clinical practice and evidenced-based practice.

STUDY DESIGN

We performed a Web-based survey of 1375 MFM providers. Participants were queried on practice characteristics and management issues including use of tocolytics, antibiotics, steroids, and timing of delivery.

RESULTS

A total of 508 providers (37%), representing all 50 states and 13 countries, responded to the survey. Only 30% reported a formal departmental protocol for managing women with PPROM. Consistent use of steroids (99.4%) and antibiotics (99.6%) were reported. Administration of steroids was confined to < or =32 weeks by 37%, and < or =34 weeks by 51% of practitioners. Repeated dosing of steroids was uncommon (16%). The antibiotics use and rationale for use varied among respondents. Tocolytics were used by 73% of respondents with magnesium sulfate the main agent used (98%). Use of tocolytics was generally used for 48 hours or less to attain steroid benefit (88%). Amniocentesis was used by 66% of practitioners in the acute evaluation of PPROM. Fetal lung maturity testing was reported by 78% with variability noted with respect to the test used. Outpatient management of women with PPROM after viability was noted by 43% of respondents. Gestational age at which expectant management is abandoned in women with PPROM varied significantly between respondents: > or =34 weeks by 56%, > pr =35 weeks by 26%, > or =36 weeks by 12%, and > or =37 weeks by 4.0%.

CONCLUSION

Although many management practices for women with PPROM are consistent with currently available evidence and practice recommendations, substantial variations still exist among MFM providers.

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

Preterm premature rupture of membranes (PPROM) occurs in 3% of pregnancies and is responsible for one third of all preterm births. In part I of this series, the definition, pathophysiology, and diagnosis of PPROM was reviewed. In this part, treatment is discussed. Adjunctive antibiotic and corticosteroid therapy has the strongest evidence for improving neonatal outcome. Treatment is gestational age-dependent and will be influenced by local neonatal intensive-care unit (NICU) survival statistics. This review presents the available evidence and grades it according to the U.S. Preventative Task Force recommendations.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to summarize the data on the use of labor inhibition in the setting of PPROM, list potential antibiotics regimens that are recommended for prophylaxis in patients with PPROM, to describe the benefits of corticosteroid administration in patients with PPROM, and to outline potential management strategies for patients with PPROM based on gestational age.

Maternal and obstetric risk factors for sudden infant death syndrome in the United States

OBJECTIVE

The objectives of this study were to 1). study the incidence of sudden infant death syndrome (SIDS) among singleton births in the United States and 2). identify maternal and obstetric risk factors for SIDS.

METHODS

A cohort of all live births in the United States from 1995 to 1998, formed the source population (n = 15627404). The data were obtained from the National Centers for Health Statistics Linked Births and Infant Deaths File. A nested case-control study was used to examine risk factors for SIDS. From this birth cohort, all SIDS deaths (n = 12404) were first identified (case group). From the remaining non-SIDS births, a 4-fold larger sample (n = 49616) was randomly selected as a control group.

RESULTS

The overall incidence of SIDS was 81.7 per 100000 live births. More mothers in the case group than in the control group were reported to have placenta previa (odds ratio [OR]: 1.70; 95% confidence interval [CI] 1.24, 2.33), abruptio placentae (OR 1.57; 95% CI 1.24, 1.98), premature rupture of membranes (OR 1.48; 95% CI 1.33, 1.66), or small for gestational age (OR 1.40; 95% CI 1.30, 1.50 for the 10th percentile). SIDS cases were also more likely to be male. Mothers of cases were more likely to be younger, less educated, and nonwhite, and more of them smoked during pregnancy and did not attend prenatal care.

CONCLUSION

This analysis confirms the importance of several well known demographic and lifestyle risk factors for SIDS. In addition, placental abnormalities were risk factors for SIDS.

LEVEL OF EVIDENCE

II-2

The timing of elective delivery in preterm premature rupture of the membranes: a survey of members of the Society of Maternal-Fetal Medicine

OBJECTIVE

We sought to assess the gestational age at which elective delivery is considered in an otherwise uncomplicated patient with preterm premature rupture of the membranes (PROM) by members of the Society of Maternal Fetal-Medicine (SMFM).

STUDY DESIGN

A 3-page survey was mailed to members of the SMFM for this observational study. Information solicited included demographic data and practice patterns for the timing of delivery in patients with preterm PROM.

RESULTS

Seven hundred seventeen questionnaires (40%) were completed. The majority (81%) did not believe there is a consensus regarding the gestational age for elective delivery in patients with preterm PROM. With confirmed fetal lung maturity, the greatest number of respondents selected 32 and 34 weeks as the earliest gestational age for elective delivery. In the absence of fetal pulmonary maturity testing, the majority of respondents chose 34 weeks.

CONCLUSION

Most SMFM respondents electively deliver uncomplicated patients with preterm PROM by 34 weeks' gestation.

The association between respiratory distress and nonpulmonary morbidity at 34 to 36 weeks' gestation

OBJECTIVE

The study was undertaken to determine whether respiratory distress syndrome (RDS) is associated with an increased risk of nonpulmonary morbidity in neonates born between 34 to 36 weeks' gestation.

STUDY DESIGN

We performed a matched case-control study of 75 infants with (cases) and 75 without (controls) RDS, delivered between 34 and 36 weeks' gestation. Infants with RDS and no other causes for respiratory failure (anomalies, hydrops, asphyxia) were included. Controls were matched for gestational age at birth, year of care, gender, plurality, and race. Inpatient records were reviewed for the incidence of nonpulmonary morbidities before discharge. McNemar test and conditional logistic regression were used to evaluate differences between cases and controls.

RESULTS

Our study cohort was 69% male, 48% white, 33% African American, and 19% Hispanic. Cases had longer hospital (11 vs 7days) and neonatal intensive care unit stays (10 vs 7 days), and more frequent apnea-bradycardia (30% vs 5%), pneumonia (12% vs 1%), and suspected sepsis diagnoses (27% vs 3%), P <or=.008 for each. Antibiotic use (96% vs 45%), transfusion (20% vs 0%), phototherapy (57% vs 29%), and hyperalimentation (57% vs 4%) were more common in the RDS group, P <or=.002 for each. Other major morbidities (intraventricular hemorrhage, patent ductus arteriosus, necrotizing enterocolitis, bronchopulmonary dysplasia) were uncommon in cases and controls. Similar results were obtained when controlling for mode of delivery and antenatal steroid use.

CONCLUSION

RDS at 34 to 36 weeks is associated with increased morbidity and neonatal interventions. In the absence of RDS, major morbidity is uncommon.

Therapies administered to mothers at risk for preterm birth and neurodevelopmental outcome in their infants

A decrease in the rate of preterm births and the prevention of prematurity-associated neurodevelopmental morbidity are critical for the reduction of neurodevelopmental disability. Efforts to reduce the overall preterm delivery rate have been unsuccessful. Although progress has been achieved in the prevention of short-term neonatal morbidity over the past several decades, the majority of the improvements have resulted from improved neonatal care. Whether obstetric interventions can improve neurodevelopmental outcome is unknown. The ability to adequately assess obstetric interventions is hampered by the limited number of interventional studies that included long-term outcome assessment. Thus, it is incumbent upon ongoing and future interventional studies to consider long-term outcome assessment as a critical component of the overall evaluation of efficacy of obstetric therapies.

[Prediction of the latency period by cervical ultrasonography in premature rupture of the membranes before term]

OBJECTIVE

To assess the value of ultrasonographic measurement of cervical length for predicting the duration of the latency period from admission to delivery in women with preterm premature rupture of the membranes (PROM).

METHOD

Prospective study in 88 women with preterm PROM before 34 weeks of amenorrhea. The median gestational age at admission was of 30.1 weeks. The clinical management included: no digital examination of the uterine cervix, antenatal corticosteroids, antibiotics (amoxicillin & clavulanic acid) for 7 days, and hoding back until 34 weeks. Cervical length at admission was determined with transvaginal ultrasonography. The duration of the latency period was studied in relation with cervical length, serum C-reactive protein (CRP) level and white blood cell (WBC) count at admission.

RESULTS

The median latency period was longer in women with a cervical length > or = 25 mm (10 vs 5 days; p = 0.04), but this was not associated with a significant increase in birth weight. The median latency period was also longer in women with CRP < 20 mg/l (10 vs 3 days; p < 0.001) and this was associated with a significant increase in birth weight (1716 +/- 549 vs 1201 +/- 485 g; p < 0.01). Moreover, increased CRP levels were more frequent in women with a cervical length < 25 mm, and cervical length was no more predictive of the duration of the latency period in the subgroup of women with CRP < 20 mg/l and WBC < 20,000 cells/mm3.

CONCLUSION

In women with preterm PROM, the latency period from admission to delivery is shorter when cervical length is < 25 mm. However, the clinical value of transvaginal ultrasonography is limited in comparison with serum CRP.

Accuracy of the TDx-FLM assay of amniotic fluid: a comparison of vaginal pool samples with amniocentesis

OBJECTIVE

The purpose of this study was to evaluate the use of the TDx-FLM fluorescence polarization assay on vaginal pool fluid in patients with preterm premature rupture of membranes (PPROM).

METHODS

A prospective matched-pairs study was performed at a tertiary care center. For each patient enrolled, amniotic fluid samples were obtained by sterile speculum examination and by amniocentesis within 12 h of each other. Inclusion criteria were the presence of PPROM and a gestational age of 30-36 weeks. The samples were analyzed separately using the TDx-FLM assay in the same laboratory. The results were compared using a paired Student t test.

RESULTS

A total of 16 patients received both amniocentesis and vaginal collection of amniotic fluid. The mean gestational age at amniocentesis was 33.3 weeks (SD 1.9). In every case, the vaginal pool TDx-FLM result was lower than the amniocentesis result. The mean difference in the assays between the two fluid sources was 35% (range 17-63%, p < 0.001). Amniocentesis suggested a mature result in 12 cases (75%), an indeterminate result in two cases (12.5%), and an immature result in two cases (12.5%). Vaginal pool fluid suggested a mature result in four cases (25%), an indeterminate result in nine cases (56%), and an immature result in three cases (19%). Using the cut-off values validated for amniocentesis specimens as a standard for comparison, vaginal pool TDx-FLM assay had 42% sensitivity, 100% specificity, 100% positive predictive value and 36% negative predictive value for predicting lung maturity.

CONCLUSIONS

The TDx-FLM assay on vaginal pool samples of amniotic fluid yielded results that were significantly different from those of amniocentesis samples. At this point, the assay is only clinically useful for vaginal pool samples when a mature result is obtained.