Accuracy of imaging parameters in the prediction of lethal pulmonary hypoplasia secondary to mid-trimester prelabor rupture of fetal membranes: a systematic review and meta-analysis

Anti-infectious and anti-inflammatory effect of amniopatch in the treatment of spontaneous previable rupture of membranes

Spontaneous previable rupture of membranes complicates approximately 0.4-0.7% of pregnancies and is associated with severe maternal and neonatal morbidity and mortality. Intra-amniotic inflammation is present in up to 94.4% of cases, most often caused by a bacterial infection. In comparison, the effectiveness of antibiotic therapy in its eradication reaches less than 17%. Inflammatory activity in the amniotic cavity disrupts the physiological development of the fetus with an increase in maternal, fetal, and neonatal inflammatory morbidity through the development of fetal inflammatory response syndrome, maternal chorioamnionitis, and neonatal sepsis. Amniopatch is an invasive therapeutic technique based on intra-amniotic administration of maternal hemoderivates in the form of thromboconcentrate and plasma cryoprecipitate to provide the temporary closure of the fetal membranes defect and secondary restitution of normohydramnios with correction of pressure-volume ratios. The supposed basis of this physical-mechanical action is the aggregation of coagulant components of amniopatch in the area of the defect with the formation of a valve cap. The background for the formulation of the hypothesis on the potential anti-infectious and anti-inflammatory action of non-coagulant components of amniopatch involved: i) clinical-academic and publishing outputs of the authors based on their many years' experience with amniopatch application in the treatment of spontaneous previable rupture of membranes (2008-2019), ii) the documented absence of clinically manifested chorioamnionitis in patients treated this way with a simultaneously reduced incidence of neonatal respiratory distress syndrome compared to expectant management (tocolysis, corticotherapy, antibiotic therapy). The non-coagulant components of plasma cryoprecipitate include mainly naturally occurring isohemagglutinins, albumin, and soluble plasma fibrinogen. Although these components of the amniopatch have not been attributed a significant therapeutic role, the authors assume that due to their opsonizing and aggregative properties, they can significantly participate in optimizing the intrauterine environment through the reduction in bacterial and cytokine charge in the amniotic fluid. The authors think these facts constitute a vital stimulus to future research-academic activity and, at the same time, an idea for reconsidering the therapeutic role of amniopatch as a tool for improving perinatal results of spontaneous previable ruptures of membranes.

Impact of preterm premature rupture of membranes and oligohydramnios on in-hospital outcomes of very-low-birthweight infants

OBJECTIVE

To analyze neonatal outcomes in very-low-birthweight (VLBW) infants depending on the presence of preterm premature rupture of membranes (PPROM), oligohydramnios, or both.

METHODS

The electronic medical records of VLBW infants admitted during the study period, January 2013 to September 2018, were reviewed. Neonatal outcomes (primary outcome: neonatal death; secondary outcome: neonatal morbidity) were compared depending on whether the infant was affected by PPROM or oligohydramnios. Logistic regression analysis was performed to assess the association of PPROM and oligohydramnios with neonatal outcomes.

RESULTS

Three hundred and nineteen VLBW infants were included: (1) 141 infants in the PPROM group vs. 178 infants in the non-PPROM group, and (2) 54 infants in the oligohydramnios group vs. 265 infants in the non-oligohydramnios group. The infants affected by PPROM were at significantly younger gestational ages at birth with lower 5-min Apgar scores than those not affected by PPROM. Histologic chorioamnionitis was significantly more frequent in the PPROM group than in the non-PPROM group. The proportions of small-for-gestational-age infants and infants affected by multiple births were significantly higher in the non-PPROM group. The median (interquartile range) PPROM latency and onset were 50.5 (9.0 - 103.0) h and 26.6 (24.1 - 28.5) weeks, respectively. Based on the logistic regression analysis assessing the association of PPROM and oligohydramnios with the significant neonatal outcome, oligohydramnios was significantly associated with neonatal death (odds ratio [OR] = 2.831, 95% confidence interval [CI] 1.447 - 5.539), air leak syndrome (OR = 2.692, 95% CI 1.224 - 5.921), and persistent pulmonary hypertension (PPH) (OR = 2.380, 95% CI 1.244 - 4.555). PPROM per se was not associated with any neonatal outcome. However, early onset PPROM and prolonged PPROM latency were associated with neonatal morbidity and mortality. When PPROM was accompanied by oligohydramnios, it was associated with increased odds for PPH (OR = 2.840, 95% CI 1.335 - 6.044), retinopathy of prematurity (OR = 3.308, 95% CI 1.325 - 8.259), and neonatal death (OR = 2.282, 95% CI 1.021 - 5.103).

CONCLUSION

PPROM and oligohydramnios affect neonatal outcomes differently. Oligohydramnios, but not PPROM, is a significant risk factor for adverse neonatal outcomes, which is presumably related to pulmonary hypoplasia. Prenatal inflammation appears to complicate neonatal outcomes in infants affected by early PPROM and prolonged PPROM latency.

Assessment of normal pulmonary development using functional magnetic resonance imaging techniques

BACKGROUND

The mainstay of assessment of the fetal lungs in clinical practice is via evaluation of pulmonary size, primarily using 2D ultrasound and more recently with anatomical magnetic resonance imaging. The emergence of advanced magnetic resonance techniques such as T2* relaxometry in combination with the latest motion correction post-processing tools now facilitates assessment of the metabolic activity or perfusion of fetal pulmonary tissue in vivo.

OBJECTIVE

This study aimed to characterize normal pulmonary development using T2* relaxometry, accounting for fetal motion across gestation.

METHODS

Datasets from women with uncomplicated pregnancies that delivered at term, were analyzed. All subjects had undergone T2-weighted imaging and T2* relaxometry on a Phillips 3T magnetic resonance imaging system antenatally. T2* relaxometry of the fetal thorax was performed using a gradient echo single-shot echo planar imaging sequence. Following correction for fetal motion using slice-to-volume reconstruction, T2* maps were generated using in-house pipelines. Lungs were manually segmented and mean T2* values calculated for the right and left lungs individually, and for both lungs combined. Lung volumes were generated from the segmented images, and the right and left lungs, as well as both lungs combined were assessed.

RESULTS

Eighty-seven datasets were suitable for analysis. The mean gestation at scan was 29.9±4.3 weeks (range: 20.6-38.3) and mean gestation at delivery was 40±1.2 weeks (range: 37.1-42.4). Mean T2* values of the lungs increased over gestation for right and left lungs individually and for both lungs assessed together (P=.003; P=.04; P=.003, respectively). Right, left, and total lung volumes were also strongly correlated with increasing gestational age (P<.001 in all cases).

CONCLUSION

This large study assessed developing lungs using T2* imaging across a wide gestational age range. Mean T2* values increased with gestational age, which may reflect increasing perfusion and metabolic requirements and alterations in tissue composition as gestation advances. In the future, evaluation of findings in fetuses with conditions known to be associated with pulmonary morbidity may lead to enhanced prognostication antenatally, consequently improving counseling and perinatal care planning.

Assessment of the fetal lungs in utero

Antenatal diagnosis of abnormal pulmonary development has improved significantly over recent years because of progress in imaging techniques. Two-dimensional ultrasound is the mainstay of investigation of pulmonary pathology during pregnancy, providing good prognostication in conditions such as congenital diaphragmatic hernia; however, it is less validated in other high-risk groups such as those with congenital pulmonary airway malformation or preterm premature rupture of membranes. Three-dimensional assessment of lung volume and size is now possible using ultrasound or magnetic resonance imaging; however, the use of these techniques is still limited because of unpredictable fetal motion, and such tools have also been inadequately validated in high-risk populations other than those with congenital diaphragmatic hernia. The advent of advanced, functional magnetic resonance imaging techniques such as diffusion and T2* imaging, and the development of postprocessing pipelines that facilitate motion correction, have enabled not only more accurate evaluation of pulmonary size, but also assessment of tissue microstructure and perfusion. In the future, fetal magnetic resonance imaging may have an increasing role in the prognostication of pulmonary abnormalities and in monitoring current and future antenatal therapies to enhance lung development. This review aims to examine the current imaging methods available for assessment of antenatal lung development and to outline possible future directions.

Treatment of Classic Mid-Trimester Preterm Premature Rupture of Membranes (PPROM) with Oligo/Anhydramnion between 22 and 26 Weeks of Gestation by Means of Continuous Amnioinfusion: Protocol of a Randomized Multicentric Prospective Controlled TRIAL and Review of the Literature

Background: The classic mid-trimester preterm premature rupture of membranes (PPROM) is defined as a rupture of the fetal membranes prior to 28 weeks of gestation (WG) with oligo/anhydramnion; it complicates approximately 0.4–0.7% of all pregnancies and is associated with very high neonatal mortality and morbidity. Antibiotics have limited success to prevent bacterial growth, chorioamnionitis and fetal inflammation. The repetitive amnioinfusion does not work because fluid is lost immediately after the intervention. The continuous amnioinfusion through the transabdominal port system or catheter in patients with classic PPROM shows promise by flushing out the bacteria and inflammatory components from the amniotic cavity, replacing amniotic fluid and thus prolonging the PPROM-to-delivery interval. Objective: This multicenter trial aims to test the effect of continuous amnioinfusion on the neonatal survival without the typical major morbidities, such as severe bronchopulmonary dysplasia, intraventricular hemorrhage, cystic periventricular leukomalacia and necrotizing enterocolitis one year after the delivery. Study Design: We plan to conduct a randomized multicenter trial with a two-arm parallel design. Randomization will be between 22/0 and 26/0 SSW. The control group: PPROM patients between 20/0 and 26/0 WG who will be treated with antibiotics and corticosteroids (from 22/0 SSW) in accordance with the guidelines of German Society of Obstetrics and Gynecology (standard PPROM therapy). In the interventional group, the standard PPROM therapy will be complemented with the Amnion Flush Method, with the amnioinfusion of Amnion Flush Solution through the intra-amnial catheter (up to 100 mL/h, 2400 mL/day). Subjects: The study will include 68 patients with classic PPROM between 20/0 and 26/0 WG. TRIAL-registration: ClinicalTrials.gov ID: NCT04696003. German Clinical Trials Register: DRKS00024503, January 2021.

Fetal Lung Echo Texture in Pregnancies at Risk for Pulmonary Hypoplasia

Pulmonary hypoplasia is associated with severe respiratory distress immediately after birth and frequently leads to neonatal death. In this study, we compared the fetal lung echo texture in pregnancies at high and low risk for pulmonary hypoplasia. Ultrasonic tissue heterogeneity was determined by a dynamic range calculation. This quantification uses a dithering technique based on the Floyd-Steinberg algorithm, in which the pixels are transformed into a binary map. Pregnancies at high risk for pulmonary hypoplasia showed decreased fetal lung heterogeneity on ultrasound imaging. This image-processing technique may allow improved risk stratification, patient counseling, and treatment approaches for pulmonary hypoplasia.

Branch pulmonary artery Doppler parameters predict early survival-non-survival in premature rupture of membranes

BACKGROUND

Preterm premature rupture of membrane (pPROM) leads to high neonatal mortality due in part to severe lung hypoplasia (LH). In other causes of severe LH, fetal echo-based parameters of smaller branch pulmonary arteries (PA), shorter acceleration to ejection time ratio (AT/ET), increased peak early diastolic reverse flow (PEDRF), and higher pulsatility index (PI) are predictive of worse neonatal outcome. We sought to determine whether these parameters correlated with worse clinical outcome in pPROM.

METHODS

Twenty-five pregnancies complicated by pPROM were prospectively recruited. Fetal echocardiography was used to evaluate branch PA diameters and Doppler parameters. Clinical records were reviewed. Fetal echo findings were compared between early survivors and non-survivors.

RESULTS

Of 25 pPROM cases, 5 had early neonatal demise (≤3 days) due to respiratory insufficiency. While gestational age at pPROM, fetal echo, and at birth did not differ, amniotic fluid index (AFI) was significantly lower in early non-survivors compared to survivors (p = 0.05). No difference was observed in PA diameter, PEDRF, or PI; however, branch PA AT/ET was significantly shorter in non-survivors (right PA median 0.12 (0.11-0.16) vs. survivors 0.17 (0.14-0.21), p = 0.046 and left PA 0.12 (0.09-0.13) vs. survivors 0.16 (0.11-0.21), p = 0.042).

CONCLUSIONS

We found a significantly lower AFI and shorter fetal bilateral branch PA AT/ET to be associated with early neonatal demise following pPROM.

Periviable Premature Rupture of Membranes

Periviable deliveries (less than 26 weeks) are a small percentage of deliveries but account for a disproportionately high number of long-term morbidities. Few studies describe interventions and outcomes for periviable preterm premature rupture of membranes (PPROM). The available reports may include only those neonates who received resuscitation, making interpretation and application difficult. Counseling should consider the impact of oligohydramnios on fetal lung development. This article discusses standard and experimental interventions that may offer neonatal benefit. Antenatal corticosteroids, antibiotics, and magnesium sulfate may improve outcomes but data to support an improvement in outcome are limited. Studies specifically evaluating these interventions are needed.

Neonatal Survivability following Previable PPROM after Hospital Readmission for Intervention

Objective  To describe our hospital's experience following expectant management of previable preterm prelabor rupture of membranes (pPPROM). Study Design  Retrospective review of neonatal survival and maternal and neonatal outcomes of pPPROM cases between 2012 and 2019 at a tertiary referral center in South Central Louisiana. Regression analyses were performed to identify predictors of neonatal survival. Results  Of 81 cases of pPPROM prior to 23 weeks gestational age (WGA), 23 survived to neonatal intensive care unit discharge (28.3%) with gestational age at rupture ranging from 18 ^0/7 to 22 ^6/7 WGA. Increased latency (adjusted odds ratio [aOR] = 1.30, 95% confidence interval [CI] = 1.11, 1.52) and increased gestational age at rupture (aOR = 1.62, 95% CI = 1.19, 2.21) increased the probability of neonatal survival. Antibiotics prior to delivery were associated with increased latency duration (adjusted hazard ratio = 0.55, 95% CI = 0.42, 0.74). Conclusion  Neonatal survival rate following pPPROM was 28.3%. Later gestational age at membrane rupture and increased latency periods are associated with increased neonatal survivability. Antibiotic administration following pPPROM increased latency duration.

Prelabor Rupture of Membranes: ACOG Practice Bulletin, Number 217

Preterm birth occurs in approximately 10% of all births in the United States and is a major contributor to perinatal morbidity and mortality (). Prelabor rupture of membranes (PROM) that occurs preterm complicates approximately 2-3% of all pregnancies in the United States, representing a significant proportion of preterm births, whereas term PROM occurs in approximately 8% of pregnancies (). The optimal approach to assessment and treatment of women with term and preterm PROM remains challenging. Management decisions depend on gestational age and evaluation of the relative risks of delivery versus the risks (eg, infection, abruptio placentae, and umbilical cord accident) of expectant management when pregnancy is allowed to progress to a later gestational age. The purpose of this document is to review the current understanding of this condition and to provide management guidelines that have been validated by appropriately conducted outcome-based research when available. Additional guidelines on the basis of consensus and expert opinion also are presented. This Practice Bulletin is updated to include information about diagnosis of PROM, expectant management of PROM at term, and timing of delivery for patients with preterm PROM between 34 0/7 weeks of gestation and 36 6/7 weeks of gestation.

Can sonographic assessment of pulmonary vascular reactivity following maternal hyperoxygenation predict neonatal pulmonary hypertension? (HOTPOT study protocol)

Background

Persistent pulmonary hypertension of the newborn (PPHN) is a condition that occurs in 0.5–7 per 1000 live births and can result in significant cardiovascular instability in the newborn. It occurs when there is a failure of the normal circulatory transition in the early newborn period. Recent studies have shown that fetal pulmonary vasculature reacts to maternal hyperoxygenation (MH). The aim of the study is to assess if the in-utero response to MH can predict pulmonary hypertension in the early newborn period.

Methods

We will perform a prospective cohort study. It will evaluate the use of fetal echocardiographic Doppler assessment of the pulmonary vasculature prior to and following MH to predict fetuses that may develop pulmonary hypertension in the neonatal period. The study will be undertaken in the Rotunda Hospital, Dublin, Ireland. A fetal ultrasound and echocardiography will be performed on fetuses in the third trimester. Blood flow velocity waveforms will be recorded during periods of fetal quiescence. Pulsatility index (PI), Resistance index (RI), Peak systolic (PSV) and end diastolic velocity (EDV), time-averaged velocity (TAV), acceleration time (AT), and ejection time (ET) will be measured within the fetal distal pulmonary artery (PA). The acceleration-to-ejection time ratio (AT: ET) will be used to assess pulmonary vascular resistance (PVR). Doppler measurements will be taken at baseline and repeated immediately following MH for 10 min (O2 100% v/v inhalational gas) at a rate of 12L/min via a partial non-rebreather mask. Doppler waveform measurements from the umbilical artery (UAD), middle cerebral artery (MCA) ductus arteriosus (DA), aortic isthmus (AoI) and ductus venosus (DV) will also be obtained. After birth, a comprehensive neonatal functional echocardiogram will be performed within the first 24 hours of life.

Discussion

This study proposes to validate methods described to date in investigating the fetal pulmonary vascular response to MH, with expansion of the study subjects to include fetuses at risk of PPHN. Evaluation of the different at-risk subgroups will be informative in relation to the fetal circulatory adaptation close to term. Prediction of neonatal pulmonary hypertension may help guide the pharmacological and neonatal ICU strategies that optimise postnatal survival.

Prenatal Diagnosis of Autosomal Recessive Renal Tubular Dysgenesis with Anhydramnios Caused by a Mutation in the AGT Gene

Autosomal recessive renal tubular dysgenesis (ARRTD) is a rare and lethal disorder that causes stillbirth or early neonatal death. Most of the reported cases are diagnosed postnatally by a histopathological hallmark of the absence or paucity of differentiated proximal tubules in kidneys. Prenatal diagnosis of ARRTD is challenging because only a few fetal features (e.g., oligohydramnios/anhydramnios, anuria) are associated with this condition. In this study, we report a fetus with ARRTD, which showed anhydramnios and invisible urinary bladder since the second trimester, followed by growth restriction and reversed end diastolic flow in the middle cerebral artery (MCA-REDF). No morphological anomaly was detected on the fetal kidneys during an ultrasound scan. The baby died of refractory hypotension the day after their birth. Genetic analysis of genes that are involved in the renin-angiotensin-aldosterone system (RAAS), which are the known genetic causes of ARRTD, identified a novel, biparental-origin homozygous c.857-619_1269+243delinsTTGCCTTGC mutation in the AGT gene. The mutation is considered as pathogenic because it is cosegregated with ARRTD and detected in other unrelated ARRTD families. Our findings link the fetal ultrasound manifestations to the ARRTD, highlighting clues that are useful for prenatal diagnosis, which warrants confirmatory genotyping of the RAAS genes including oligohydramnios/anhydramnios, anuria (absent filling of a fetal urinary bladder), MCA-REDF, and a morphologically normal kidney.

Imagiological methods for prediction of fetal pulmonary hypoplasia: a systematic review

OBJECTIVE

To compare the different imagiological methods for prediction of fetal pulmonary hypoplasia (PH) in general diseases and associated with preterm rupture of membranes (PROM), and congenital diaphragmatic hernia (CDH).

METHODS

According to PRISMA guidelines, all the literature on PH from 1988 to 2018 was reviewed. Twenty-nine articles were selected and analyzed for two- and three- dimensional-ultrasounds (2D and 3D-US) as predictors for the lethal outcome.

RESULTS

Overall, the results identify a general gap correlating prenatal pulmonary measurements and survival at birth; discrepant predictive values for the same imagiological methods are explained by the group heterogeneity in terms of diseases and degree of severity, with the 2D measurements being more affected than 3D; 2D and 3D-US present equally predictive values for groups with 0% of survival. Regarding PROM, results demonstrate comparable accuracies for similar survival rates suggesting a useful predictive value of 2D-US in outcome estimation; they also identify ultrasonographic methods as a more accurate prognostic factor than gestational age at rupture, latency or amniotic fluid index. In CDH, consistent with previous studies, our review shows magnetic resonance imaging as a better survival predictor followed by the 3D and 2D methods, while 2D-LHR was the more precise prognosticator correlating prenatal PH, survival at birth, and the need for neonatal respiratory support.

CONCLUSION

Ultrasonographic methods can be valuable predictors for lethal PH and should be validated for a broad set of diseases (e.g. PROM). For that, restricted studies for disease groups and correlating fetal PH with the needed of neonatal support, and survival at birth is critically recommended.

[Antenatal management in case of preterm premature rupture of membranes before fetal viability: CNGOF Preterm Premature Rupture of Membranes Guidelines]

OBJECTIVES

To evaluate the maternal, perinatal and long-term prognosis in the event of previable premature rupture of the membranes (PROM) and to specify the interventions likely to reduce the risks and improve the prognosis.

METHODS

The PubMed database, the Cochrane Library and the recommendations from the French and foreign obstetrical societies or colleges have been consulted.

RESULTS

Previable PROM is a rare event whose frequency varies from 0.3 to 1% according to estimates (NP4). When occurring as a complication of amniocentesis, the prognosis is generally better than when spontaneous (NP3). Between 23 and 39% of women will deliver in the week following PROM and nearly 40% of women will not have given birth 2 weeks after (NP3). The frequency of medical termination of pregnancy varies greatly according to the studies (NP4), as does that of fetal death (NP4). Hospital survival and survival rates without major morbidity as a proportion of conservatively treated patients range from 17-55% and 26-63%, respectively (NP4). Neonatal prognosis is largely dominated by prematurity and its complications (NP3). The frequency of maternal sepsis varies from 0.8 to 4.8% in the most recent studies (NP4). Only one case of maternal death is reported, although 3 cases were identified in France between 2007 and 2012 (NP3). Information is a major component of the care to be provided to women and their partners (Professional consensus). An initial period of hospitalization may be proposed after previable PROM (Professional consensus). Thereafter, there is no argument to recommend hospital management rather than extra-hospital management when there is no argument in favour of intrauterine infection (Professional consensus). An evaluation of the amount of amniotic fluid by ultrasound may be proposed at the initial consultation and after a period of 7 to 14 days if pregnancy continues (Professional consensus). Prophylactic antibiotic treatment is recommended as soon as PROM is diagnosed (Professional consensus). The gestational age at which corticosteroid therapy may be proposed will depend on the thresholds selected for neonatal resuscitation care. In particular, it will take into account parental positioning (Professional consensus). From the time of the decision to perform neonatal resuscitation until the gestational age of 32 weeks, it is recommended to administer MgSO₄ to the woman whose delivery is imminent (Grade A). Tocolysis is not recommended in this context (Professional consensus). In certain situations, meeting strictly the conditions mentioned by the CSP article L. 2213-1, a maternal request for medical interruption of pregnancy may be discussed.

CONCLUSION

The levels of evidence of scientific work on the management of previable PROM are low, therefore, most of the recommendations proposed here are based on professional agreement by "reasonable" extension of recommendations valid for later gestational ages.

Mid-trimester preterm premature rupture of membranes (PPROM): etiology, diagnosis, classification, international recommendations of treatment options and outcome

Mid-trimester preterm premature rupture of membranes (PPROM), defined as rupture of fetal membranes prior to 28 weeks of gestation, complicates approximately 0.4%-0.7% of all pregnancies. This condition is associated with a very high neonatal mortality rate as well as an increased risk of long- and short-term severe neonatal morbidity. The causes of the mid-trimester PPROM are multifactorial. Altered membrane morphology including marked swelling and disruption of the collagen network which is seen with PPROM can be triggered by bacterial products or/and pro-inflammatory cytokines. Activation of matrix metalloproteinases (MMP) have been implicated in the mechanism of PPROM. The propagation of bacteria is an important contributing factor not only in PPROM, but also in adverse neonatal and maternal outcomes after PPROM. Inflammatory mediators likely play a causative role in both disruption of fetal membrane integrity and activation of uterine contraction. The "classic PPROM" with oligo/an-hydramnion is associated with a short latency period and worse neonatal outcome compared to similar gestational aged neonates delivered without antecedent PPROM. The "high PPROM" syndrome is defined as a defect of the chorio-amniotic membranes, which is not located over the internal cervical os. It may be associated with either a normal or reduced amount of amniotic fluid. It may explain why sensitive biochemical tests such as the Amniosure (PAMG-1) or IGFBP-1/alpha fetoprotein test can have a positive result without other signs of overt ROM such as fluid leakage with Valsalva. The membrane defect following fetoscopy also fulfils the criteria for "high PPROM" syndrome. In some cases, the rupture of only one membrane - either the chorionic or amniotic membrane, resulting in "pre-PPROM" could precede "classic PPROM" or "high PPROM". The diagnosis of PPROM is classically established by identification of nitrazine positive, fern positive watery leakage from the cervical canal observed during in specula investigation. Other more recent diagnostic tests include the vaginal swab assay for placental alpha macroglobulin-1 test or AFP and IGFBP1. In some rare cases amniocentesis and infusion of indigo carmine has been used to confirm the diagnosis of PPROM. The management of the PPROM requires balancing the potential neonatal benefits from prolongation of the pregnancy with the risk of intra-amniotic infection and its consequences for the mother and infant. Close monitoring for signs of chorioamnionitis (e.g. body temperature, CTG, CRP, leucocytes, IL-6, procalcitonine, amniotic fluid examinations) is necessary to minimize the risk of neonatal and maternal complications. In addition to delayed delivery, broad spectrum antibiotics of penicillin or cephalosporin group and/or macrolide and corticosteroids have been show to improve neonatal outcome [reducing risk of chorioamnionitis (average risk ratio (RR)=0.66), neonatal infections (RR=0.67) and abnormal ultrasound scan of neonatal brain (RR=0.67)]. The positive effect of continuous amnioinfusion through the subcutaneously implanted perinatal port system with amniotic fluid like hypo-osmotic solution in "classic PPROM" less than 28/0 weeks' gestation shows promise but must be proved in future prospective randomized studies. Systemic antibiotics administration in "pre-PPROM" without infection and hospitalization are also of questionable benefit and needs to be further evaluated in well-designed randomized prospective studies to evaluate if it is associated with any neonatal benefit as well as the relationship to possible adverse effect of antibiotics on to fetal development and neurological outcome.

ACOG Practice Bulletin No. 188: Prelabor Rupture of Membranes

Preterm delivery occurs in approximately 12% of all births in the United States and is a major factor that contributes to perinatal morbidity and mortality (1, 2). Preterm prelabor rupture of membranes (also referred to as premature rupture of membranes) (PROM) complicates approximately 3% of all pregnancies in the United States (3). The optimal approach to clinical assessment and treatment of women with term and preterm PROM remains controversial. Management hinges on knowledge of gestational age and evaluation of the relative risks of delivery versus the risks of expectant management (eg, infection, abruptio placentae, and umbilical cord accident). The purpose of this document is to review the current understanding of this condition and to provide management guidelines that have been validated by appropriately conducted outcome-based research when available. Additional guidelines on the basis of consensus and expert opinion also are presented.

Prenatal prediction of pulmonary hypoplasia

Pulmonary hypoplasia, although rare, is associated with significant neonatal morbidity and mortality. Conditions associated with pulmonary hypoplasia include those which limit normal thoracic capacity or movement, including skeletal dysplasias and abdominal wall defects; those with mass effect, including congenital diaphragmatic hernia and pleural effusions; and those with decreased amniotic fluid, including preterm, premature rupture of membranes, and genitourinary anomalies. The ability to predict severe pulmonary hypoplasia prenatally aids in family counseling, as well as obstetric and neonatal management. The objective of this review is to outline the imaging techniques that are widely used prenatally to assess pulmonary hypoplasia and to discuss the limitations of these methods.

Practice Bulletin No. 172: Premature Rupture of Membranes

Preterm delivery occurs in approximately 12% of all births in the United States and is a major factor that contributes to perinatal morbidity and mortality (1, 2). Preterm premature rupture of membranes (PROM) complicates approximately 3% of all pregnancies in the United States (3). The optimal approach to clinical assessment and treatment of women with term and preterm PROM remains controversial. Management hinges on knowledge of gestational age and evaluation of the relative risks of delivery versus the risks of expectant management (eg, infection, abruptio placentae, and umbilical cord accident). The purpose of this document is to review the current understanding of this condition and to provide management guidelines that have been validated by appropriately conducted outcome-based research when available. Additional guidelines on the basis of consensus and expert opinion also are presented.

Evaluating skeletal dysplasias on prenatal ultrasound: an emphasis on predicting lethality

Lethal skeletal dysplasias can be diagnosed by prenatal ultrasound (US) using several sonographic parameters. Degree of femoral shortening, lung volumes, femur length to abdominal circumference ratio, and chest circumference to abdominal circumference ratio are the most sensitive and specific predictors. Although there are more than 450 different skeletal dysplasias, only a few are lethal in the perinatal period. We review current fetal US literature and present an updated algorithmic approach to first establish lethality and, second, evaluate for hallmark sonographic features to help determine a specific diagnosis.

Reference ranges for 2-dimensional sonographic lung measurements in healthy fetuses: a longitudinal study

OBJECTIVES

The purpose of this study was to establish reference ranges for 2-dimensional sonographic measurements of fetal lungs from longitudinal data.

METHODS

A total of 214 fetal lung measurements were longitudinally evaluated in 62 healthy fetuses between 20 and 36 weeks' menstrual age. Both right and left lung areas were measured in the heart 4-chamber view using lung area tracing and axis diameter methods. Multilevel modeling was used to evaluate the expected values and variability with respect to menstrual age and to generate reference ranges for the lung area, lung-to-head ratio, quantitative lung index, and observed-to-expected lung-to-head ratio for both lungs.

RESULTS

The expected values varied with menstrual age for all parameters. Variance was menstrual age dependent for all parameters except the longest diameter area measurements and their lung-to-head ratios.

CONCLUSIONS

Models are presented for expected 2-dimensional sonographic lung size parameters and their variance as a function of menstrual age. These data have been used to generate age-specific reference ranges for both measurements and indices.

Incorporating quality assessments of primary studies in the conclusions of diagnostic accuracy reviews: a cross-sectional study

Background

Drawing conclusions from systematic reviews of test accuracy studies without considering the methodological quality (risk of bias) of included studies may lead to unwarranted optimism about the value of the test(s) under study. We sought to identify to what extent the results of quality assessment of included studies are incorporated in the conclusions of diagnostic accuracy reviews.

Methods

We searched MEDLINE and EMBASE for test accuracy reviews published between May and September 2012. We examined the abstracts and main texts of these reviews to see whether and how the results of quality assessment were linked to the accuracy estimates when drawing conclusions.

Results

We included 65 reviews of which 53 contained a meta-analysis. Sixty articles (92%) had formally assessed the methodological quality of included studies, most often using the original QUADAS tool (n = 44, 68%). Quality assessment was mentioned in 28 abstracts (43%); with a majority (n = 21) mentioning it in the methods section. In only 5 abstracts (8%) were results of quality assessment incorporated in the conclusions. Thirteen reviews (20%) presented results of quality assessment in the main text only, without further discussion. Forty-seven reviews (72%) discussed results of quality assessment; the most frequent form was as limitations in assessing quality (n = 28). Only 6 reviews (9%) further linked the results of quality assessment to their conclusions, 3 of which did not conduct a meta-analysis due to limitations in the quality of included studies. In the reviews with a meta-analysis, 19 (36%) incorporated quality in the analysis. Eight reported significant effects of quality on the pooled estimates; in none of them these effects were factored in the conclusions.

Conclusion

While almost all recent diagnostic accuracy reviews evaluate the quality of included studies, very few consider results of quality assessment when drawing conclusions. The practice of reporting systematic reviews of test accuracy should improve if readers not only want to be informed about the limitations in the available evidence, but also on the associated implications for the performance of the evaluated tests.

Adverse respiratory outcome after premature rupture of membranes before viability

AIM

To determine whether preterm premature rupture of membranes (PPROM) before 24 weeks is an independent risk factor for poor outcome in preterm neonates.

METHODS

A retrospective comparative cohort study was conducted, including viable premature infants born between 25 and 34-weeks gestation. Each preterm case with early PPROM was matched with two preterm controls of the same gestational age at birth, sex and birth date and who were born spontaneously with intact membranes. Logistic regression was performed to identify independent risk factors associated with composite respiratory and perinatal adverse outcomes for the overall population of preterm infants.

RESULTS

Thirty-five PPROM cases were matched with 70 controls. Extreme prematurity (26-28 weeks) was an independent risk factor for composite perinatal adverse outcomes [odds ratio (OR) 43.9; p = 0.001]. Extreme prematurity (OR 42.9; p = 0.001), PPROM (OR 7.1; p = 0.01), male infant (OR 5.2; p = 0.02) and intrauterine growth restriction (IUGR, OR 4.8; p = 0.04) were factors for composite respiratory adverse outcomes.

CONCLUSION

Preterm premature rupture of membranes before viability represents an independent risk factor for composite respiratory adverse outcomes in preterm neonates. Extreme prematurity may represent the main risk factor for both composite respiratory and perinatal adverse outcomes.

Economical Analysis of Different Clinical Approaches in Pre-Viability Amniorrhexis-A Case Series

Prolonged oligohydramnios following extreme preterm prelabour rupture of membranes (EPPROM) is traditionally associated with a high morbidity and mortality to both the mother and the baby. The clinical maternal evaluation and fetal ultrasound assessment may provide important prognostic information for the clinicians and should be taken into account when counselling the patients so as to provide them with enough information to make decision of continuing or interrupting the pregnancy. Current financial constraints on the National Healthcare Service (NHS) resources make it imperative for clinical decision-makers and budgetary planners to make the right decision of continuing or terminating a second trimester pre-viability amniorrhexis for desperate parents. To assess the economic consequences following EPPROM, the risk of infection to both baby and mother, psychological impact on the parents and associated complications and further disability after delivery on this fragile group of patients to the NHS resources. We review the clinical course, outcome, and the challenges to parents and health care professionals on three pregnancies complicated by EPPROM, occurring before 24 weeks’ gestation with a membrane rupture to delivery interval (latent period) of 14 days or more. The anticipated birth of an extremely premature infant poses many challenges for parents and health care professionals. As parents are faced with difficult decisions that can have a long-term impact on the infant, family and country’s resources, it is critical to provide the type of information and support that is needed by them. Taking all these into consideration with the period of ventilation and respiratory assistance in Neonatal Intensive Care Unit (NICU) is essential to provide maximum chances for survival, minimizing the risk for long term sequelae of the neonate and provides the parents enough time to decide on making the right decision with the associated guidance of the healthcare provider.

Practice bulletins No. 139: premature rupture of membranes

Preterm delivery occurs in approximately 12% of all births in the United States and is a major factor that contributes to perinatal morbidity and mortality (). Preterm premature rupture of membranes (PROM) complicates approximately 3% of all pregnancies in the United States (). The optimal approach to clinical assessment and treatment of women with term and preterm PROM remains controversial. Management hinges on knowledge of gestational age and evaluation of the relative risks of delivery versus the risks of expectant management (eg, infection, abruptio placentae, and umbilical cord accident). The purpose of this document is to review the current understanding of this condition and to provide management guidelines that have been validated by appropriately conducted outcome-based research when available. Additional guidelines on the basis of consensus and expert opinion also are presented.