Ultrasonographic prediction of lethal pulmonary hypoplasia: comparison of eight different ultrasonographic parameters

Value of fetal echocardiographic examination in pregnancies complicated by preterm premature rupture of membranes

OBJECTIVES

Cardiopulmonary and infectious complications are more common in preterm newborns after preterm premature rupture of membranes (pPROM). Fetal echocardiography may be helpful in predicting neonatal condition. Our aim was to assess the cardiovascular changes in fetuses from pregnancies complicated by pPROM and possible utility in predicting the intrauterine or neonatal infection, and neonatal heart failure (HF).

METHODS

It was a prospective study enrolling 46 women with singleton pregnancies complicated by pPROM between 18+0 and 33+6 weeks of gestation and followed until delivery. 46 women with uncomplicated pregnancies served as a control group. Fetal echocardiographic examinations with the assessment of cardiac structure and function (including pulmonary circulation) were performed in all patients.

RESULTS

Mean gestational age of pPROM patients was 26 weeks. Parameters suggesting impaired cardiac function in fetuses from pPROM were: higher right ventricle Tei index (0.48 vs. 0.42 p<0.001), lower blood flow velocity in Ao z-score (0.14 vs. 0.84 p=0.005), lower cardiovascular profile score (CVPS), higher rate of tricuspid regurgitation (18.2 % vs. 4.4 % p=0.04) and pericardial effusion (32.6 vs. 0 %). Intrauterine infection was diagnosed in 18 patients (39 %). 4 (8.7 %) newborns met the criteria of early onset sepsis (EOS). HF was diagnosed in 9 newborns. In fetal echocardiographic examination HF group had shorter mitral valve inflow time and higher left ventricle Tei index (0.58 vs. 0.49 p=0.007).

CONCLUSIONS

Worse cardiac function was observed in fetuses from pPROM compared to fetuses from uncomplicated pregnancies.

Lung Hypoplasia in Fetuses with Skeletal Dysplasia Determined by Fetal Lung Weight: Which Ultrasound Measurement/Ratio Has the Highest Detection Rate

INTRODUCTION

To determine lung hypoplasia in cases with fetal skeletal dysplasia based on the total lung weight at autopsy as the most accountable surrogate marker for pulmonary hypoplasia.

METHODS

This retrospective cohort study included all pregnancies with antenatal diagnosis of skeletal dysplasia (2012-2018). We included only cases in which information on fetal biometry was available within 2 weeks before delivery and had autopsy and skeletal X-rays + molecular analysis using extracted fetal DNA. We compared the predictive accuracy of fetal sonographic body-proportional ratios (BPRs) including: (1) thoracic circumference-to-abdominal circumference ratio, (2) the femur length-to-abdominal circumference (FL/AC) ratio, (3) head circumference-to-abdominal circumference ratio, and (4) foot length-to-femur length ratio. Lung hypoplasia was defined as total lung weight below -2 SD from the expected mean for gestational age.

RESULTS

Fifty three pregnancies with antenatal diagnosis of skeletal dysplasia underwent autopsy included. Lung hypoplasia was determined in 34 (64.1%). Median of gestational age at last sonographic assessment was 21.3 (19.9-24.9) weeks. FL/AC ratio demonstrated the highest area under the curve of 0.817 (95% CI: 0.685-0.949; p < 0.0001). FL/AC ≤0.1550 demonstrated the highest detection rate of 88.2% along with the highest negative predictive value of 75%.

CONCLUSION

Using a novel, more practical approach to predict lung hypoplasia in skeletal dysplasia, fetal sonographic BPRs and, specifically, FL/AC ratio demonstrate a high detection rate of lung hypoplasia.

Fetal thoracic circumference in mid-pregnancy and infant lung function

BACKGROUND AND AIM

Impaired lung function in early infancy is associated with later wheeze and asthma, while fetal thoracic circumference (TC) predicts severity of neonatal lung hypoplasia. Exploring fetal origins of lung function in infancy, we aimed to determine if fetal TC in mid-pregnancy was associated with infant lung function.

METHODS

From the prospective Scandinavian general population-based PreventADALL mother-child birth cohort, all 851 3-month-old infants with tidal flow-volume measurements in the awake state and ultrasound fetal size measures at 18 (min-max 16-22) weeks gestational age were included. Associations between fetal TC and time to peak tidal expiratory flow to expiratory time (t_PTEF /t_E ) were analyzed in linear regression models. To account for gestational age variation, we adjusted TC for simultaneously measured general fetal size, by head circumference (TC/HC), abdominal circumference (TC/AC), and femur length (TC/FL). Multivariable models were adjusted for maternal age, maternal asthma, pre-pregnancy body mass index, parity, nicotine exposure in utero, and infant sex.

RESULTS

The infants (47.8% girls) were born at mean (SD) gestational age of 40.2 (1.30) weeks. The mean (SD) t_PTEF /t_E  was 0.39 (0.08). The mean (SD) TC/HC was 0.75 (0.04), TC/AC 0.87 (0.04), and TC/FL 4.17 (0.26), respectively. Neither TC/HC nor TC/AC were associated with infant t_PTEF /t_E while a week inverse association was observed between TC/FL and t_PTEF /t_E  ( β ^ $\hat{\beta }$  = -0.03, 95% confidence interval [-0.05, -0.007], p = 0.01).

CONCLUSION

Mid-pregnancy fetal TC adjusted for fetal head or abdominal size was not associated with t_PTEF /t_E in healthy, awake 3-month-old infants, while a weak association was observed adjusting for fetal femur length.

Fetal Thoracic Circumference and Lung Volume and Their Relation to Fetal Size and Pulmonary Artery Blood Flow

OBJECTIVE

Research on early origins of lung disease suggests the need for studying the relationships of thoracic and lung size with fetal size and pulmonary circulation. The primary aim of this study is therefore to explore the associations between fetal thoracic circumference, lung volume, and fetal size. We also aim to assess if lung volume and thoracic circumference are associated with fetal pulmonary artery blood flow velocity measures.

METHODS

Cross-sectional assessment of singleton pregnancies from the general population (n = 447) at 30 gestational weeks (GW) was performed using ultrasound measurement of fetal thoracic circumference, lung volume, head and abdominal circumference, and femur length. We obtained Doppler blood flow velocity measures from the proximal branches of the fetal pulmonary artery. Associations between variables were studied using Pearson's correlation and multiple linear regression analyses.

RESULTS

Both thoracic circumference and lung volume correlated with fetal size measures, ranging from r = 0.64 between thoracic circumference and abdominal circumference, to r = 0.28 between lung volume and femur length. Adjustment for gestational age, maternal nicotine use, pre-pregnancy body mass index, and fetal sex marginally influenced the associations with abdominal circumference. The correlations of thoracic circumference and lung volume with pulmonary artery blood flow velocity measures were weak (r ≤ 0.17).

CONCLUSION

We found moderate to low correlation between thoracic circumference, lung volume, and fetal size at 30 GW. The closest relationship was with the abdominal circumference. We found low correlations of thoracic circumference and lung volume with pulmonary artery blood flow velocity measures.

Fetal ciliopathies: a retrospective observational single-center study

Purpose

Report on the diagnosis of prenatally suspected multisystem ciliopathies in a single center between 2002 and 2020.

Methods

Retrospective observational single-center study including pregnancies with prenatal ultrasound features of multisystem ciliopathies, such as hyperechogenic kidneys together with polydactyly and/or other skeletal and extraskeletal findings. Cases were compared according to their prenatal findings and outcomes.

Results

36 cases of multisystem ciliopathies were diagnosed. Meckel-Gruber syndrome (MKS) was the most common ciliopathy (n = 19/36, 52.8%), followed by disorders that belong to the group of short-rib thoracic dysplasia (SRTD, n = 10/36, 27.8%) McKusick–Kaufmann syndrome (MKKS, n = 4/36, 11.1%), Bardet–Biedl syndrome (BBS, n = 2/36, 5.5%) and Joubert syndrome (n = 1/36, 2.8%). All cases showed abnormalities of the kidneys, most often hyperechogenic parenchyma (n = 26/36, 72.2%), cystic dysplasia (n = 24/36, 66.7%), and/or bilateral kidney enlargement (n = 22/36, 61.1%). Oligohydramnios was mainly present in fetuses with MKS. Polydactyly (n = 18/36), abnormalities of the CNS (n = 25/36), and heart defects (n = 10/36) were associated in 50%, 69.4%, and 27.8%, respectively.

Conclusion

Prenatal detection of renal abnormalities associated with skeletal or brain abnormalities should raise the suspicion for multisystem ciliopathies. Prenatal ultrasound can help to differentiate between different diseases and pave the way for subsequent targeted genetic testing.

Pediatric rib pathologies: clinicoimaging scenarios and approach to diagnosis

Pathologies involving the ribs are diverse in nature, including entities specific to the pediatric population as well as shared pathologies with adults. These can be either localized within or adjacent to the rib, but may also cause rib alteration as a component of a systemic process. To better understand these disorders, we discuss several common rib pathologies in the context of their clinical presentation and pertinent imaging findings. In addition, we review the imaging modalities that may be used to evaluate the ribs. Encompassing both the clinical and imaging aspects of pediatric rib pathologies, this review aims to increase pediatric and musculoskeletal radiologists' awareness of the spectrum of disease and how to leverage a pattern-based approach.

Antenatal diagnostic dilemma in a pseudodominant pedigree with lamin-B receptor (LBR)-related regressive spondylometaphyseal dysplasia

The lamin-B receptor (LBR) encodes a dual-functioning inner nuclear membrane protein essential for cholesterol biosynthesis and chromatin organization. LBR pathogenic variants cause distinct phenotypes due to the dual function of LBR, including Pelger-Huët anomaly (PHA), PHA with mild skeletal anomalies (PHASK; MIM# 618019), LBR-related regressive type of spondylometaphyseal dysplasia (LBR-R-SMD), Greenberg dysplasia (MIM# 215140). We here report the first case with radiological manifestations of LBR-R-SMD in the fetal period, and milder skeletal findings in the similarly affected father. Direct sequencing of LBR revealed homozygous c.1534C>T (p.Arg512Trp) in exon 12 in both affected individuals. Our report further refines the early phenotype in LBR-R-SMD, and demonstrates that the p.Arg512Trp mutation is associated with PHA. We propose that LBR-R-SMD should be considered as a differential diagnosis in pregnancies with sonographic evidence of short and bowed tubular bones with narrow thorax. Evaluating peripheral blood smears of expectant parents for the presence of PHA may lead to a clinical diagnosis, allowing for comprehensive prenatal genetic counseling.

Prenatal features and neonatal management of severe hyperparathyroidism caused by the heterozygous inactivating calcium-sensing receptor variant, Arg185Gln: A case report and review of the literature

Background

Loss-of-function variants in the calcium-sensing receptor (CASR) gene are known to be involved in a clinical spectrum ranging from asymptomatic familial hypocalciuric hypercalcemia (FHH) to neonatal severe hyperparathyroidism (NSHPT). Homozygous or compound heterozygous variants are usually responsible for severe neonatal forms, whereas heterozygous variants cause benign forms. One recurrent pathogenic variant, p.Arg185Gln, has been reported in both forms, in a heterozygous state. This variant can be a de novo occurrence or can be inherited from a father with FHH.

NSHPT leads to global hypotonia, failure to thrive, typical X-ray anomalies (diffuse demineralization, fractures, metaphyseal irregularities), and acute respiratory distress which can be fatal. Phosphocalcic markers show severe hypercalcemia, abnormal urinary calcium resorption, and hyperparathyroidism as major signs.

Classical treatment involves calcium restriction, hyperhydration, and bisphosphonates. Unfortunately, the disease often leads to parathyroidectomy. Recently, calcimimetics have been used with variable efficacy. Efficacy in NSHPT seems to be particularly dependent on CASR genotype.

Case presentation

We describe the antenatal presentation of a male with short ribs, initially suspected having skeletal ciliopathy. At birth, he presented with NSHPT linked to the pathogenic heterozygous CASR variant, Arg185Gln, inherited from his father who had FHH. Postnatal therapy with cinacalcet was successful.

Discussion

An exhaustive literature review permits a comparison with all reported cases of Arg185Gln and to hypothesize that cinacalcet efficacy depends on CASR genotype. This confirms the importance of pedigree and parental history in antenatal short rib presentation and questions the feasibility of phosphocalcic exploration during pregnancy or prenatal CASR gene sequencing in the presence of specific clinical signs. It could in fact enable early calcimimetic treatment which might be effective in the CASR variant Arg185Gln.

Anatomical Considerations of Embryology and Development of the Musculoskeletal System: Basic Notions for Musculoskeletal Radiologists

The musculoskeletal (MSK) system begins to form in the third week of intrauterine development. Multiple genes are involved in the complex different processes to form the skeleton, muscles and joints. The embryonic period, from the third to the eighth week of development, is critical for normal development and therefore the time when most structural defects are induced. Many of these defects have a genetic origin, but environmental factors may also play a very important role. This review summarizes the embryology of the different components of the MSK system and their configuration as an organ-system, analyzes the clinical implications resulting from failures in the process of organogenesis, and describes the first approach to diagnosis of skeletal abnormalities using prenatal ultrasound.

Imaging of Congenital Skeletal Disorders

Osteochondrodysplasias are the result of the expression of gene mutations. The phenotypes in osteochondrodysplasias evolve through life, with the possibility that previously unaffected bones may be involved at later stages of growth. Due to the variable time of onset, the diagnosis may be made prenatally, at birth, or later. Certainty in the diagnosis is sometimes only achieved as the patient matures and the disease evolves. Radiographic evaluation is a fundamental part of the diagnostic work-up of congenital skeletal disorders and in most cases the first tool used to arrive at a diagnosis. This review describes the imaging characteristics, specific signs, and evolution of several skeletal dysplasias in which diagnosis may be directly or indirectly suggested by radiologic findings. A definitive accurate diagnosis of a congenital skeletal abnormality is necessary to help provide a prognosis of expected outcomes and to counsel parents and patients.

Current Overview of Osteogenesis Imperfecta

Osteogenesis imperfecta (OI), or brittle bone disease, is a heterogeneous disorder characterised by bone fragility, multiple fractures, bone deformity, and short stature. OI is a heterogeneous disorder primarily caused by mutations in the genes involved in the production of type 1 collagen. Severe OI is perinatally lethal, while mild OI can sometimes not be recognised until adulthood. Severe or lethal OI can usually be diagnosed using antenatal ultrasound and confirmed by various imaging modalities and genetic testing. The combination of imaging parameters obtained by ultrasound, computed tomography (CT), and magnetic resource imaging (MRI) can not only detect OI accurately but also predict lethality before birth. Moreover, genetic testing, either noninvasive or invasive, can further confirm the diagnosis prenatally. Early and precise diagnoses provide parents with more time to decide on reproductive options. The currently available postnatal treatments for OI are not curative, and individuals with severe OI suffer multiple fractures and bone deformities throughout their lives. In utero mesenchymal stem cell transplantation has been drawing attention as a promising therapy for severe OI, and a clinical trial to assess the safety and efficacy of cell therapy is currently ongoing. In the future, early diagnosis followed by in utero stem cell transplantation should be adopted as a new therapeutic option for severe OI.

Fetal lung maturity assessment: A historic perspective and Non - invasive assessment using an automatic quantitative ultrasound analysis (a potentially useful clinical tool)

Immature fetal lung is associated with many adverse outcomes including respiratory distress syndrome and transient tachypnoea of the newborn. Several methods/tools have been used over several decades to assess fetal lung maturity prior to delivery. Some of the methods that have been used to assess fetal lung maturity include amniocentesis for the biochemical markers, lecithin and sphingomyelin, lamellar body counts, gray scale ultrasound scan and magnetic resonance imaging. Amniocentesis an invasive procedure which carries a small risk of miscarriage has almost become obsolete. Magnetic resonance imaging on the other hand is expensive and not very practical. Quantitative ultrasound fetal lung maturity (quantusFLM) assessment is a new technique aimed at assessing fetal lung texture using ultrasound. The technique depends on visualization of fetal lungs at the level of the 4- chamber view. Images obtained are then uploaded via a web page application and these are analyzed remotely and results generated in minutes. The analysis depends on studying changes in the texture of lung images that depend on changes at histological level especially of collagen, fat and water. These changes are undetectable to the human eye. Randomized clinical trials have shown this technique to be accurate, reproducible, and completely non - invasive. The aim of this review was to take a historic look at methods/tools for assessing fetal lug maturity and discuss further advances and a potential non-invasive tool/method especially the non-invasive assessment that combines ultrasound scan and machine learning to accurately assess lung maturity.

Prenatal prediction of neonatal haemodynamic adaptation after maternal hyperoxygenation

Abstract

The reactivity of the pulmonary vascular bed to the administration of oxygen is well established in the post-natal circulation. The vasoreactivity demonstrated by the fetal pulmonary artery Doppler waveform in response to maternal hyperoxia has been investigated. We sought to investigate the relationship between the reactivity of the fetal pulmonary arteries to hyperoxia and subsequent neonatal cardiac function in the early newborn period.

Methods

This explorative study with convenience sampling measured pulsatility index (PI), resistance index (RI), acceleration time (AT), and ejection time (ET) from the fetal distal branch pulmonary artery (PA) at baseline and following maternal hyperoxygenation (MH). Oxygen was administered for 10 min at a rate of 12 L/min via a partial non-rebreather mask. A neonatal functional echocardiogram was performed within the first 24 h of life to assess ejection fraction (EF), left ventricular output (LVO), and neonatal pulmonary artery AT (nPAAT). This study was conducted in the Rotunda Hospital, Dublin, Ireland.

Results

Forty-six women with a singleton pregnancy greater than or equal to 31 weeks’ gestational age were prospectively recruited to the study. The median gestational age was 35 weeks. There was a decrease in fetal PAPI and PARI following MH and an increase in fetal PAAT, leading to an increase in PA AT:ET. Fetuses that responded to hyperoxygenation were more likely to have a higher LVO (135 ± 25 mL/kg/min vs 111 ± 21 mL/kg/min, p < 0.01) and EF (54 ± 9% vs 47 ± 7%,p = 0.03) in the early newborn period than those that did not respond to MH prenatally. These findings were not dependent on left ventricular size or mitral valve (MV) annular diameter but were related to an increased MV inflow. There was no difference in nPAAT.

Conclusion

These findings indicate a reduction in fetal pulmonary vascular resistance (PVR) and an increase in pulmonary blood flow and left atrial return following MH. The fetal response to hyperoxia reflected an optimal adaptation to postnatal life with rapid reduction in PVR increasing measured cardiac output.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-020-03403-y.

Obstetric complications in pregnancies with life-limiting malformations

PURPOSE OF REVIEW

The implementation of palliative care at birth has led to a significant rise in the number of couples who choose to continue with pregnancies complicated by life-limiting malformations (LLMs). Prenatal counselling and appropriate antenatal/perinatal management in these cases are poorly studied and may pose significant challenges. The purpose of this review is to outline specific obstetric risks and to suggest management for mothers who choose to continue with pregnancies with the most common LLMs.

RECENT FINDINGS

In pregnancies complicated by LLMs where parents opt for expectant management, clinicians should respect parental wishes, whilst openly sharing potential serious maternal medical risks specific for the identified abnormalities. The focus of both antenatal and perinatal care should be maternal wellbeing rather than foetal survival. Follow-up ultrasound examinations and maternal surveillance should be aimed at achieving timely diagnosis and effective management of obstetric complications. A clear perinatal plan, agreed with the couples by a multi-disciplinary team including a foetal medicine specialist, a neonatologist and a geneticist, is crucial to reduce maternal morbidity.

SUMMARY

This review provides a useful framework for clinicians who face the challenges of counselling and managing cases complicated by LLMs where parents opt for pregnancy continuation.

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.

Fetal micromelia, thoracic dysplasia and polydactyly revisited: A case-based antenatal sonographic approach

Introduction

Skeletal dysplasia is a condition associated with various abnormalities of the skeleton and comprises multiple groups of disorders. Antenatal ultrasonographic assessment of the skeletal dysplasia requires a robust and systematic assessment of the long bones, fetal thorax, skull, spine, pelvis, hands and the feet. Large number of diseases, their overlapping phenotypic features and the lack of systematic approach lead to diagnostic inefficiency. A precise molecular diagnosis also requires an elaborate antenatal sonographic assessment to reach a final diagnosis.

Case report

A fetus with micromelia, thoracic dysplasia and polydactyly was detected on prenatal sonography. An algorithmic approach of this rare combination on prenatal sonography is highlighted.

Discussion

Fetal micromelia is a relatively common entity which can be subclassified into mild and severe types. The lethal nature of the condition requires assessment of the thoracic biometry which may further narrow down the diagnostic possibilities. The red flags or highlighting features of various conditions like polydactyly, hitch-hiker thumb deformity, ovoid tibia and absent fibula may lead to a specific diagnosis.

Conclusion

A background knowledge of various types of micromelia, their lethal nature, associations and specific features of various differential skeletal dysplasia will always be useful, if employed in a systematic manner.

Pulmonary hypoplasia in fetuses with congenital conotruncal defects

OBJECTIVES

We sought to investigate pulmonary hypoplasia (PH) and associated risk factors in fetuses with congenital conotruncal defect (CTD).

METHODS

A total of 75 fetuses with CTD (gestational age (GA): 22-32 weeks) and 150 normal GA-matched fetuses as the control group were studied. We measured diameters of aorta (Ao); main, left, and right pulmonary artery (PA); and their Z-scores by fetal echocardiography (FE). We also measured the lung area, lung area/chest area ratio (LCR), lung-to-head circumference ratio (LHR), right lung area/head circumference² (quantitative lung index, QLI), and Z-scores.

RESULTS

The PA, left pulmonary artery (LPA), RPA, and their Z-scores and the lung area measurements (except for QLI) were significantly smaller in the CTD group, compared with the normal control group. Subgroup analysis showed the following: (1) CTD with right ventricular outflow tract obstruction (RVOTO) had smaller main and branch PA dimensions and small lung areas in contrast to CTD without RVOTO. (2) CTD with pulmonary atresia had smaller LPA and RPA dimensions but no difference in lung areas. (3) In the common types of CTD, lung area variables were mostly smaller in double outlet right ventricle (DORV) and tetralogy of Fallot (TOF), but there was no difference in transposition of the great arteries (TGA).

CONCLUSIONS

CTD is associated with hypoplastic main and branch pulmonary arteries as well as PH. Risk factors for PH included defect types (DORV and TOF but not TGA) and RVOTO. It is plausible that pulmonary blood flow, rather than the type of CTD, RVOTO, or pulmonary artery dimensions, plays a key role in PH.

Postmortem Characteristics of Lung Hypoplasia at Diaphragmatic Hernia: MRI – Pathomorphological Comparisons

Purpose: the study of postmortem MRI possibilities for the diagnosis of lung hypoplasia in congenital diaphragmatic hernia.

Materials and methods. A comparison of the results of postmortem MRI study and data of pathoanatomical autopsy of 23 newborns was performed. In group I, the bodies of 10 deceased newborns with congenital diaphragmatic hernia without operative intervention were examined. In group II – the bodies of 7 newborns who died after surgery for congenital diaphragmatic hernia. Group III (control) included 6 bodies of newborns without diaphragmatic hernia and signs of lung hypoplasia. Before the autopsy, an MRI study was performed on a 3T Magnetom Verio device (Siemens, Germany) in standard T1 and T2 modes. The volumes of the lungs and chest cavity were calculated in the analysis of the tomograms data and their 3D reconstruction. The stage of the lung development and number of radial alveoli were identified at the microscopic study of histological preparations.

Results.As a result of the postmortem MRI study, it was established that the observations of group I are characterized by minimal lung volumes. The mean lung volume on the side of the diaphragmatic hernia was 4.1 times less than the contralateral lung (p < 0.01), and the mean values of the volume of both lungs were 4.6 times less than the corresponding values of the control group (p < 0.01) . The average value of the specific volume of the lungs in newborns who died as a result of congenital diaphragmatic hernia (group I) was 8.8%, which is 4.2 times less than the control group (p < 0.01) and was accompanied by histological signs of hypoplasia. The operation in Group II observations led to an increase in lung size. However, the specific volume of the lungs in this group remained by 18.6% less than the control group, and on histological specimens there were signs of lung hypoplasia.

Conclusion.The postmortem MRI of dead newborns allows for an objective quantification of lung volumes and verifies the presence of hypoplasia. This helps to clarify the pathogenesis and determine the immediate cause of death. Indices of specific lung volume relative to the chest cavity of less than 20% indicate lung hypoplasia as the immediate cause of death of the newborn.

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.

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.

Approach to the diagnosis of skeletal dysplasias: Experience at a center with limited resources

PURPOSE

A fetus with skeletal disorder poses diagnostic challenges in a resource-poor setting with limited management options. The objective of the study was to develop a step-by-step approach for the diagnosis of skeletal dysplasia in light of the limited resources available.

METHODS

An algorithmic approach was used. The assessment for lethality was the first step, followed by the evaluation for fractures. In cases without evidence of fracture, severe constriction of thorax or associated polydactyly were searched for. In cases without severe thoracic constriction, the severity of micromelia was evaluated. After delivery, fetal examination was done to ascertain the etiology.

RESULTS

During the 6-year period, 41 cases with shortened long bones were fully evaluated. Lethality was suspected in 30 cases. Fracture and beading were present in eight cases, and severe thoracic constriction with polydactyly was observed in seven cases. Mild micromelia was seen in 19 cases and severe micromelia in 7 cases. Among lethal skeletal dysplasias, thanatophoric dysplasia was most common (six cases). Among nonlethal skeletal dysplasias, achondroplasia was seen in eight cases.

CONCLUSIONS

Lethality of skeletal dysplasia could be predicted on prenatal ultrasound with 100% accuracy. The step-by-step approach was helpful to characterize skeletal dysplasias. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:529-539, 2016.

Prediction of lethal pulmonary hypoplasia by means fetal lung volume in skeletal dysplasias: a three-dimensional ultrasound assessment

OBJECTIVE

The aim of this study was to assess the capacity of three-dimensional ultrasound (3DUS) for predicting lethality in fetuses with skeletal dysplasia.

METHODS

Twenty-four fetuses between 20 and 32 weeks of gestation were assessed. Bilateral lung volume scans were performed three times in each fetus during one ultrasound session. The virtual organ computer-aided analysis method was used to obtain a sequence of six sections of each lung around a fixed axis, and a rotation angle of 30° was adopted. Fetal lung volume measurements were analyzed according to the reference range. After birth, lung hypoplasia was diagnosed considering clinical and radiological criteria.

RESULTS

Of all cases of skeletal dysplasia, 18 (75%) were lethal. Among the lethal cases, after postnatal diagnosis, four were osteogenesis imperfecta type II, three were thanatophoric dysplasia and two were campomelic dysplasia. The remaining nine cases remained without a definitive diagnosis. The accuracy of 3DUS in predicting lethality in fetuses with skeletal dysplasia was high, with a sensitivity of 83.3%, specificity of 100%, positive predictive value of 100% and negative predictive value of 66.7%. The kappa index of 0.174 showed a good agreement between the possibility of lethality when the 3DUS volume measurement was altered and real lethality after birth (p < 0.001).

CONCLUSION

This study suggests that the 3DUS lung volume measurement is a good predictor of lethal pulmonary hypoplasia in fetuses with skeletal dysplasia, with high accuracy.

Antenatal Diagnosis of Jeune Syndrome (Asphyxiating Thoracic Dysplasia) with Micromelia and Facial Dysmorphism on Second-Trimester Ultrasound

Background

Jeune syndrome is a rare congenital malformation with a reported incidence of 1 in 100,000–130,000 live births. Thoracic hypoplasia is the most striking abnormality of this disorder. Here we report a case of Jeune syndrome with marked thoracic hypoplasia, micromelia and facial dysmorphism, which was diagnosed on a second-trimester antenatal real-time three-dimensional ultrasound.

Case Report

A 24-year-old primigravida came for routine anomaly scan at 19 weeks of gestation. Transabdominal grey scale and real time 3D ultrasound (US) was done with GE Logiq P5 with curvilinear array transducers (4C and 4D3C-L). US findings were consistent with the diagnosis of Jeune syndrome (Asphyxiating thoracic dysplasia).

Conclusions

Jeune syndrome is an extremely rare congenital disorder with a spectrum of abnormalities of which thoracic hypoplasia is the most striking. It can be diagnosed on early antenatal US by its characteristic skeletal and morphological features which can guide further management of pregnancy in form of termination or preparation for surgical correction of the deformity.

Prenatal diagnosis of fetal respiratory function: evaluation of fetal lung maturity using lung-to-liver signal intensity ratio at magnetic resonance imaging

Objective

The purpose of this retrospective study is to determine the fetal lung-to-liver signal intensity ratio (LLSIR) on T2-weighted images for the prediction of neonatal respiratory outcome.

Methods

One hundred ten fetuses who underwent magnetic resonance imaging (MRI) examination for various indications after 22 weeks of gestation participated in this study. LLSIR was measured as the ratio of signal intensities of the fetal lung and liver on T2-weighted images at MRI. We examined the changes of the ratio with advancing gestation and the relations between LLSIR and the presence of the severe respiratory disorder (SRD) after birth. The best cut-off value of the LLSIR to predict respiratory outcome after birth was calculated using receiver operating characteristic (ROC) curve analysis.

Results

Lung-to-liver signal intensity ratio correlated significantly with advancing gestational age (R = 0.35, p < 0.001). The non-SRD group had higher LLSIR compared with the SRD group (2.15 ± 0.30 vs. 1.53 ± 0.40, p < 0.001). ROC curve analysis showed that fetuses with an LLSIR < 2.00 were more likely to develop SRD [sensitivity: 100%, 95% confidence interval (CI): 52–100%; specificity: 73%, 95% CI 54–88%].

Conclusion

The fetal LLSIR on T2-weighted images is an accurate marker to diagnose the fetal lung maturity. © 2014 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd.

Fibrochondrogenesis: prenatal diagnosis and outcome

We studied 20 cases with fibrochondrogenesis (FCG) diagnosed prenatally. Four cases were diagnosed at our fetal unit, and 16 cases were identified through a review of literature (in English). The prenatal diagnosis of FCG was made in 4/20 (20%). Six (30%) patients opted for termination of pregnancy (TOP). A total of 13 cases delivered at term. Four (30.8%) had a caesarean section. Four neonates (30.7%) were stillborn and seven (53.8%) neonates died within 3 months. Two infants survived beyond 3 years of age, but both had severe global developmental delay. A molecular study of the surviving children revealed two null homozygous mutations in COL11A1 [c.4084C > T (p.R1362X) and c.3708 + c.437T > G]. We concluded that the prenatal diagnosis of fibrochondrogenesis is feasible. Fibrochondrogenesis is usually a fatal disease and survivors suffer from severe physical and neurological impairment.

Advances in evaluating the fetal skeleton

In this review, we discuss aspects of the prenatal diagnosis of fetal skeletal malformations, concentrating on the advantages offered by different imaging techniques and the approaches that are of value in evaluating a suspected skeletal dysplasia. We also briefly address the findings in some of the commoner malformations of the fetal skeleton that may be encountered.

New anatomical landmarks to study the relationship between fetal lung area and thoracic circumference by three-dimensional ultrasonography

OBJECTIVE

To evaluate the relation between total lung area (TLA) and thoracic circumference (TC) ratio by three-dimensional (3D) ultrasonography applying new anatomical landmarks as the fetal aorta and inferior angle of the scapula.

METHODS

A longitudinal prospective study was conducted with 56 uncomplicated pregnancies between 24 and 32 weeks of gestation. Polynomial regressions were used to evaluate the correlation between TC and gestational age (GA) as well as TC and estimated fetal weight (EFW). A simple linear regression was used to evaluate the correlation between TLA and Total thoracic area (TTA) and GA. The intraclass correlation coefficient (ICC) was used to assess the intra and interobserver variability.

RESULTS

127 examinations were performed. TC values ranged from 150 to 174 mm (mean 166 mm) at 24 weeks and 215-248 mm (mean 231 mm) at 32 weeks. The TLA/TC ratio ranged from a mean of 0.64 at 24 weeks (range 0.56-0.70) to 0.90 at 32 weeks gestation (range 0.79-1.01). The intraobserver variability using the ICC was of 0.919 for TC; 0.916 for TTA; 0.860 for right lung area (RLA) and 0.910 for left lung area (LLA). Interobserver reproducibility was with an ICC of 0.970 for TC; 0.984 for RLA and 0.910 for LLA.

CONCLUSIONS

Measurement of fetal TC and the relationship between TLA and TC by 3D-ultrasonography applying new anatomical landmarks shows good reproducibility and allows a new assessment of thoracic and lung growth.

Hypophosphatasia: nonlethal disease despite skeletal presentation in utero (17 new cases and literature review)

Hypophosphatasia (HPP) is caused by deactivating mutation(s) within the gene that encodes the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). Patients manifest rickets or osteomalacia and dental disease ranging from absence of skeletal mineralization in utero to only loss of adult dentition. Until recently, HPP skeletal disease in utero was thought to always predict a lethal outcome. However, several reports beginning in 1999 emphasized a benign prenatal form of HPP (BP-HPP) where skeletal disease detected in utero had a mild postnatal course. Here we describe prenatal and postnatal findings of 17 additional BP-HPP patients among our 178 pediatric HPP patients. Their findings are compared with those of their siblings with HPP, carrier parents, and others with identical TNSALP mutations. New information concerning 7 previously published BP-HPP patients accompanies a review of the HPP literature. Among our 17 BP-HPP patients, prenatal ultrasound showed normal chest or abdominal circumferences where recorded. Sometimes, poor skeletal mineralization, fetal crowding, and third-trimester improvement were observed. Postnatally, extremity bowing further improved (13 patients). BP-HPP severity postnatally spanned the "infantile" to "odonto" HPP phenotypes, resembling our patients who harbored identical TNSALP mutation(s). Eight had autosomal dominant (AD) and 9 had autosomal recessive (AR) BP-HPP. Fourteen of our 15 mothers were HPP carriers or affected. Of the 41 cumulative BP-HPP patients (24 literature cases meriting a BP-HPP diagnosis since 1996 plus our 17 patients), 63% had AR BP-HPP. Maternally transmitted HPP involved 11 of the 13 total AD BP-HPP probands (p = 0.01), supporting a maternal in utero effect on the baby. Fetal crowding, normal fetal mineralization and chest size, and TNSALP heterozygosity seem to identify BP-HPP. However, bowed fetal long bones with AR HPP, specific TNSALP mutations, or poor skeletal mineralization before the third trimester do not reliably diagnose HPP lethality.

FGFR3 related skeletal dysplasias diagnosed prenatally by ultrasonography and molecular analysis: presentation of 17 cases

Fibroblast Growth Factor Receptor 3 (FGFR3) related skeletal dysplasias are caused by mutations in the FGFR3 gene that result in increased activation of the receptors causing alterations in the process of endochondral ossification in all long bones, and include achondroplasia, hypochondroplasia, thanatophoric dysplasia, and SADDAN. Reports of prenatal diagnosis of FGFR3 related skeletal dysplasias are not rare; however, the correlation between 2nd trimester ultrasonographic findings and underlying molecular defect in these cases is relatively poor. There is a need for specific ultrasound (U/S) predictors than can distinguish lethal from non-lethal cases and aid an earlier prenatal diagnosis. Here we present one familial and 16 sporadic cases with FGFR3 related skeletal dysplasia, and we evaluate biometric parameters and U/S findings consistent with the diagnosis of skeletal dysplasia. U/S scan performed even at the 18th week of gestation can indicate a decreased rate of development of the femora (femur length (FL) <5th centile), while the mean gestational age at diagnosis is still around the 26th week. The utility of other biometric parameters and ratios is discussed (foot length, BPD, HC, FL/foot, and FL/AC). Prenatal cytogenetic and molecular genetic analyses were performed. A final diagnosis was reached by molecular analysis. In two cases of discontinued pregnancy, fetal autopsy led to a phenotypic diagnosis and confirmed the prenatal prediction of lethality. We conclude that the combination of U/S and molecular genetic approach is helpful for establishing an accurate diagnosis of FGFR3-related skeletal dysplasias in utero and subsequently for appropriate genetic counselling and perinatal management.

Three-dimensional ultrasound fetal lung volumes and infant respiratory outcome: a prospective observational study

OBJECTIVE

To determine if fetal lung volumes (FLVs), determined by three-dimensional rotational ultrasound and virtual organ computer-aided analysis software (vocal), correlated with neonatal respiratory outcomes in surviving infants who had a high risk [fetuses with congenital diaphragmatic hernia (CDH)], lower risk [fetuses with anterior wall defects (AWDs)] and no risk (controls) of abnormal antenatal lung growth.

DESIGN

Prospective observational study.

SETTING

Tertiary fetal medicine and neonatal intensive care units.

POPULATION

Sixty fetuses (25 with CDH, 25 with AWDs and ten controls).

METHODS

FLVs were measured and expressed as the percentage of the observed compared with the expected for gestational age.

MAIN OUTCOME MEASURES

Neonatal respiratory outcome was determined by the duration of supplemental oxygen, mechanical ventilation and dependencies, and assessment of lung volume using a gas dilution technique to measure functional residual capacity (FRC).

RESULTS

The infants with CDH had lower FLV results than both the infants with AWDs (P=0.05) and the controls (P<0.05). The infants with CDH had longer durations of mechanical ventilation (P<0.001) and supplementary oxygen (P<0.001) dependence, compared with infants with AWDs. The infants with CDH had a lower median FRC than both the infants with AWDs (P<0.001) and the controls (P<0.001). FLV results correlated significantly with the durations of dependency on ventilation (r= -0.744, P<0.01) and oxygen (r= -0.788, P<0.001), and with FRC results (r=0.429, P=0.001).

CONCLUSIONS

These results suggest that FLVs obtained using three-dimensional rotational ultrasound might be useful in predicting neonatal respiratory outcome in surviving infants who had varying risks of abnormal lung growth. Larger and more comprehensive studies are needed to clarify the role that lung volume measurements have in assessing lung function and growth.

Prenatal management of urogenital disorders

Antenatal sonography has markedly increased the detection of urogenital anomalies, including those conditions that lead to significant morbidity and mortality. Prenatal intervention is feasible to arrest and sometimes reverse the sequelae of bladder outlet obstruction but not necessarily renal damage. Myelomeningoceles, the most severe form of spina bifida, can be corrected in utero, with improvements in hydrocephalus seen along with a decreased incidence of ventricular shunting postnatally. Medical therapy to prevent virilization associated with congenital adrenal hyperplasia has been successful, with improved ability to detect its presence prenatally now possible. As further techniques evolve to correct underlying disease processes, it becomes important to critically assess the therapies, particularly with long-term outcome data.

Suspected fetal skeletal malformations or bone diseases: how to explore

Skeletal dysplasias are a heterogeneous and complex group of conditions that affect bone growth and development and result in various anomalies in shape and size of the skeleton. Although US has proved reliable for the prenatal detection of skeletal abnormalities, the precise diagnosis of a dysplasia is often difficult to make before birth (especially in the absence of a familial history) due to their various phenotypic presentations, the variability in the time at which they manifest and often, the lack of precise molecular diagnosis. In addition to the accuracy of the antenatal diagnosis, it is very important to establish a prognosis. This is a clinically relevant issue as skeletal dysplasias may be associated with severe disability and may even be lethal. We will therefore describe the respective role of two-dimensional (2-D) US, three-dimensional (3-D) US and CT in the antenatal assessment of skeletal malformations.

The management of preterm premature rupture of the membranes near the limit of fetal viability

Preterm premature rupture of the membranes near the limit of fetal viability is an uncommon complication of pregnancy, affecting approximately 4 in 1000 gravidas. However, maternal, fetal, and neonatal complications resulting from this condition are significant and include chorioamnionitis, pulmonary hypoplasia, restriction deformities, fetal loss, and complications of extreme prematurity among surviving infants. In this article, we review the literature regarding pregnancy outcomes after preterm premature rupture of the membranes near the limit of viability, and the data on traditional and nontraditional interventions to improve outcomes. An approach to patients who present with preterm premature rupture of the membranes near the limit of viability will be proposed.

Guidelines for the prenatal diagnosis of fetal skeletal dysplasias

The osteochondrodysplasias, or skeletal dysplasias are a genetically heterogeneous group of over 350 distinct disorders, and many of them can present in the prenatal period as demonstrated by ultrasound. Differentiating these disorders in the prenatal period can be challenging because they are rare and many of the ultrasound findings are not necessarily pathognomic for a specific disorder. However, differentiating known lethal disorders from nonlethal disorders, providing differential diagnoses before delivery, determining postdelivery management plans and ultimately determining accurate recurrences risks to the at-risk couples improves patient care. These guidelines provide an approach to a fetus suspected of manifesting a skeletal dysplasia.

Fetal skeletal dysplasia: an approach to diagnosis with illustrative cases

Skeletal dysplasias are a heterogeneous group of conditions associated with various abnormalities of the skeleton. These conditions are caused by widespread disturbance of bone growth, beginning during the early stages of fetal development and evolving throughout life. Despite recent advances in imaging, fetal skeletal dysplasias are difficult to diagnose in utero due to a number of factors, including the large number of skeletal dysplasias and their phenotypic variability with overlapping features, lack of precise molecular diagnosis for many disorders, lack of a systematic approach, the inability of ultrasonography (US) to provide an integrated view, and variability in the time at which findings manifest in some skeletal dysplasias. US of suspected skeletal dysplasia involves systematic imaging of the long bones, thorax, hands and feet, skull, spine, and pelvis. Assessment of the fetus with three-dimensional US has been shown to improve diagnostic accuracy, since additional phenotypic features not detectable at two-dimensional US may be identified. The radiologist plays a major role in making an accurate diagnosis; however, representatives of other disciplines, including clinicians, molecular biologists, and pathologists, can also provide important diagnostic information.

The lung-to-thorax transverse area ratio at term and near term correlates with survival in isolated congenital diaphragmatic hernia

OBJECTIVE

The purpose of this study was to determine how well liver position, the lung area-to-head circumference (L/H) ratio, and the lung-to-thorax transverse area (L/T) ratio predicted the need for extra-corporeal membrane oxygenation (ECMO) and survival in fetuses with isolated congenital diaphragmatic hernia (CDH).

METHODS

Antenatal records of 25 fetuses with isolated left-sided CDH who were born by cesarean delivery under fetal stabilization at this institution were reviewed. The latest determinations of the L/H and L/T ratios before birth (between 34 and 38 weeks' gestation) were compared on the basis of the cutoff points for mortality: less than 1.0 versus 1.0 or greater for the L/H ratio and 0.08 or less versus greater than 0.08 for the L/T ratio. Outcome measures assessed were survival (discharge to home) and the need for ECMO.

RESULTS

Overall survival was 64% (16/25). Postnatal survival in fetuses with an L/T ratio of 0.08 or less was statistically lower than in those with an L/T ratio of greater than 0.08 (33% versus 81%; P = .0308). The percentage requiring ECMO in the group with an L/T ratio of 0.08 or less was also higher than that of the group with an L/T ratio of greater than 0.08, but the difference was not statistically significant (67% versus 25%; P = .0872). Neither the L/H ratio nor herniation of the fetal liver into the chest affected survival or the need for ECMO.

CONCLUSIONS

In fetuses with isolated CDH at term or near term, the L/T ratio may be a better predictor of outcome than the L/H ratio or liver herniation.

Predicting pulmonary hypoplasia with 2- or 3-dimensional ultrasonography in complicated pregnancies

OBJECTIVE

The aim of this study was to compare 3-dimensional (3D) lung volume measurements with 2-dimensional (2D) biometric parameters in predicting pulmonary hypoplasia in complicated pregnancies.

STUDY DESIGN

In this prospective study, 1-4 scans of the fetal lungs were obtained in 33 pregnancies complicated by various disorders or complications with regard to pulmonary hypoplasia. The 3D lung volumes vs gestational age or estimated fetal weight, the thoracic circumference vs gestational age or femur length, the thoracic/abdominal circumference ratio, and the thoracic/heart area ratio were measured.

RESULTS

Of the 33 infants, 16 (48.5%) were diagnosed with pulmonary hypoplasia on postmortem examination or the clinical and radiological presentation. Three dimensional lung volume measurements had a better diagnostic accuracy for predicting pulmonary hypoplasia (sensitivity, 94%; specificity, 82%; positive predictive value [PPV], 83%; negative predictive value [NPV], 93%), compared with the best 2D biometric measurement thoracic/heart area ratio (sensitivity, 94%; specificity, 47%; PPV, 63%; NPV, 89%).

CONCLUSION

3D lung volume measurements seem to be useful in predicting pulmonary hypoplasia prenatally.

Comparison of two- and three-dimensional ultrasonography in lung volume measurement of normal fetuses

AIM

The purpose of this study was to compare the two- and three-dimensional methods for measuring fetal lung volume of normal fetuses.

METHODS

A cross-sectional study was performed with 51 normal pregnant women between 20 and 35 weeks. The ellipsoid formula (X*Y*Z*0.52) was used for volume calculation with the two-dimensional (2D) method. With the VOCAL (Virtual Organ Computer-aided Analysis) method, a rotation angle of 30 degrees was used. Intraclass correlation coefficient (ICC), paired Student's t-test and Bland-Altman plots were used to compare the techniques. To calculate the intraobserver variability we used the ICC and compared the means between the two measures using the paired Student's p-test.

RESULTS

VOCAL and 2D methods were highly correlated (ICC=0.919 and 0.873 for the right and left lungs, respectively), however, there was a disagreement. The fetal lung volume means calculated by the 2D method were always overestimated in relation to the means obtained by the VOCAL, for the right lung (24.02 mL x 19.15 mL; P<0.001), as well as for the left (16.03 mL x 13.77 mL; P=0.002). As for the intraobserver variability, a good reproducibility was observed for the volume measurement of the left lung by the 2D technique (mean=0.40 mL; P=0.57) and by the VOCAL (mean=-0.22 mL; P=0.63). The 2D method, however, presented low reproducibility for the right lung (mean=1.73 mL; P=0.31).

CONCLUSION

The two-dimensional method had low agreement and low reproducibility in relation to the three-dimensional method for measurement of fetal lung volume in normal fetuses.

Relationship between L/T ratio and LHR in the prenatal assessment of pulmonary hypoplasia in congenital diaphragmatic hernia

The lung to thorax transverse area ratio (L/T ratio) and the lung area to head circumference ratio (LHR) have been widely used for the assessment of pulmonary hypoplasia in fetal congenital diaphragmatic hernia (CDH). The aim of this study was to evaluate the relationship between the L/T ratio and the LHR, and to clarify the characteristics of these two indicators as prognostic predictors by means of retrospective concurrent measurements from the same subjects with prenatally diagnosed fetal CDH. The medical records of 55 fetuses who had undergone a prenatal evaluation of isolated CDH from 1988 to 2006 were studied. The L/T ratio and the LHR were determined as the early values (earliest measurement performed earlier than 33 weeks of gestation) and as the late values (latest measurement performed later than 34 weeks of gestation) and analyzed, as well as the clinical data. Of the 55 infants, 13 died resulting in a 76.4% survival rate. A correlation expressed in the linear equation [(LHR) = 14.4 x (L/T ratio) - 0.11] was recognized between the early L/T ratio and the early LHR. All cases with an early L/T ratio of less than 0.08, or with an early LHR less than 1.2, died. Of the 13 cases, 5 with an early L/T ratio not lower than 0.08, but less than 0.13, died. Of the 17 cases, 4 with an early LHR not lower than 1.2, but less than 2.0, died. All cases with an early L/T ratio not lower than 0.13, or with an early LHR not lower than 2.0, survived. In 24 cases, the late values, which were measured at an interval of more than 4 weeks, were compared with the early values. Although the L/T ratio was consistent, the LHR increased in the late value compared to the early value. A good linear correlation was recognized between the L/T ratio and the LHR in the early phase of gestation, and the cutoff point of the prognostic prediction was determined in both indicators. In contrast to the L/T ratio, a definite cutoff point throughout the gestation may not be available in the LHR, because there is a natural increase of the LHR in the late phase of gestation.

Management of premature rupture of membranes before 25 weeks

OBJECTIVES

The aim of our study was to define the benefits and risks related to expectant management in the midtrimester rupture of membranes and to assess the prognostic factors in order to give objective informations to parents facing these obstetrical situations.

STUDY DESIGN

We conducted a retrospective study. The study population included 49 patients with premature rupture of membranes at 16-23 weeks' gestation during the period January 1998-June 2003. The main criterion for judgement was neonate survival. Statistical analysis included chi2-test for the qualitative variables and Student's test for the quantitative variables. The threshold for significance was 5%.

RESULTS

Twenty couples out of 49 chose medical termination of pregnancy. Among the 29 other pregnancies, the mean latency period was 2.1 weeks. The mean gestational age at delivery was 23.2 weeks. Nineteen patients were delivered after 22 weeks. The main prognostic factors were the initial amniotic fluid index (2.9 cm versus 0.8 cm) (p=0.042) and gestational age at delivery (26.7 weeks versus 22.6 weeks) (p<0.001). About 2% of the pregnancies were complicated by maternal infection. Eighty-three percent of the survivors had neonatal respiratory distress syndrome. 41.2% of them presented sepsis. We observed no cases of severe intraventricular haemorrhage. The number of infants born after 24 weeks of gestation and still alive at 1 week was 12, representing 24% of pregnancies and 63% of the infants born after 24 weeks.

CONCLUSION

Expectant management can be widely suggested to patients. However, termination of pregnancy is acceptable, in cases with a poor prognosis including anamnios and premature rupture of membranes before 21 weeks.

Two- or three-dimensional ultrasonography to predict pulmonary hypoplasia in pregnancies complicated by preterm premature rupture of the membranes

OBJECTIVES

The purpose of this study was to compare 3D lung volume measurements with 2D biometric parameters in predicting pulmonary hypoplasia in pregnancies complicated by preterm premature rupture of the membranes (PPROM).

METHODS

In this prospective study, 18 pregnancies complicated by PPROMs at a mean 21 weeks' gestation (range 14-32 weeks) were examined. The 3D lung volume measurements and the following 2D biometric parameters were measured: thoracic circumference (TC) versus gestational age or femur length (FL), the TC/abdominal circumference (AC) ratio and the thoracic area/heart area (TA/HA) ratio. The sensitivity, specificity, positive and negative predictive value of each measurement to diagnose pulmonary hypoplasia were compared. Pulmonary hypoplasia was diagnosed on the basis of clinical, radiological and/or pathologic criteria.

RESULTS

The incidence of pulmonary hypoplasia was 33.3%. The best diagnostic accuracy for predicting pulmonary hypoplasia was achieved using the 3D lung volume measurements versus gestational age (sensitivity 83%, specificity 100%, positive predictive value 100% and negative predictive value 92%).

CONCLUSIONS

Three-dimensional lung volume measurements seem to be promising in predicting pulmonary hypoplasia prenatally in pregnancies complicated by PPROM.

A guide to the recognition of skeletal disorders in the fetus

The discovery of fetal skeletal abnormality on prenatal US mandates an extended study of the fetus. This extended examination includes specific views and measurements of the fetal skeleton. Lethality can be predicted if severe pulmonary hypoplasia is present. Specific diagnosis of a fetal osteochondrodysplasia is difficult; a collaborative approach among obstetric, neonatal and genetic services is necessary to provide the parents with all available information regarding the pregnancy. Pediatric radiologists who have experience in radiologic assessment of osteochondrodystrophies of infants and children can provide expertise in this area.

Normal fetal lung volume measured with three-dimensional ultrasound

OBJECTIVES

To construct reference intervals for fetal lung volumes measured longitudinally using three-dimensional (3D) ultrasound, and to evaluate the effect of gender on lung size.

METHODS

This was a prospective, longitudinal study in the obstetric outpatient department of the VU University Medical Center, Amsterdam. Seventy-eight women with uncomplicated pregnancies were scanned three to four times at gestational ages of 18-34 weeks. 3D models of the lung were constructed using the ultrasound machine's software. After the infants were delivered the entire group was reanalyzed with regard to fetal gender. Centiles for the lung volumes of the entire group and for each gender separately were estimated using multilevel modeling.

RESULTS

Charts and tables of right and left fetal lung volumes, using gestational age and estimated fetal weight as the independent variables, are presented. There was a significant difference in lung volume between male and female fetuses at each gestational age. Charts and tables of right and left fetal lung volumes for each gender at gestational ages of 18-34 weeks are also presented.

CONCLUSIONS

We present valid references for volumetric measurements of the right and left fetal lungs in male and female fetuses. The feasibility and reliability of fetal lung volume measurements using 3D ultrasound is good.