Prenatal Identification of Pierre Robin Sequence: A Review of the Literature and Look towards the Future

Prenatal Diagnosis of Pierre Robin Sequence and Its Prognosis: A Retrospective Cohort Study

OBJECTIVE

 This study aimed to explore the efficiency of ultrasound (US) in prenatal diagnosis and prognosis of Pierre Robin sequence (PRS) of 18 cases.

STUDY DESIGN

 A total of 79,305 women admitted for prenatal US examinations were recruited from January 2017 to December 2020. Eighteen cases of PRS fetuses were selected form the cohort and 40 cases of isolated micrognathia were recruited randomly as control group. All the clinical and imaging results were retrospectively reviewed. General condition, US measurements, and prognosis of fetuses were compared between groups.

RESULTS

 Cleft palate, glossoptosis, and micrognathia were found in all 18 fetuses with PRS by prenatal US. Compared with the isolated micrognathia group, there were no significant differences in the PRS group in examination of maternal age, gestational weeks at assessment, and gender of fetuses, but significant lower measures in inferior facial angle, jaw index, and frontal nasal-mental angle (each p < 0.05). Twelve fetuses were defined to have other associated malformations. Ear malformations were the most common associated malformations with a prevalence of 44.4% (8/18). All of the18 cases were confirmed with PRS after delivery or autopsy. Two delivered infants were found bucking easily, one baby was spitting up frequently but growth showed normal.

CONCLUSION

 Prenatal detection of PRS with US examination is highly efficient. Even with the triad of malformations, isolated PRS had good outcomes following initial stabilization and management in the neonatal period. Prenatal detection of Pierre Robin syndrome with targeted US examination is efficient in discerning characteristics of this rare syndrome. Even with the triad of malformations, isolated PRS had good outcomes following initial stabilization and management in the neonatal period.

KEY POINTS

· Prenatal diagnosis of fetal PRS is of great clinical importance.. · Micrognathia has been identified as the primary feature of PRS.. · Posterior displacement of the tongue may cause acute neonatal respiratory distress.. · Even with triad malformation, isolated PRS seemed to have good outcomes..

Respiratory outcomes after cleft palate closure in Robin sequence: a retrospective study

OBJECTIVES

There is a paucity of information about the possible risk factors that could identify patients with Robin sequence (RS) who are more prone to developing obstructive airway complications after palate closure. This study aimed to compare the respiratory complication rates in patients with RS and isolated cleft palate (ICP).

MATERIALS AND METHODS

In this retrospective study, we reviewed the medical records of 243 consecutive patients with RS and ICP who were treated at Amsterdam University Medical Centers over the past 25 years. We collected preoperative data on previous treatment, diagnostic findings, surgical technique, weight, and presence of congenital anomalies.

RESULTS

During cleft palate closure, patients with RS were older (11.9 versus 10.1 months; p = 0.001) and had a lower gestational age than those with ICP (37.7 versus 38.5 weeks; p = 0.002). Patients with RS had more respiratory complications (17 versus 5%; p = 0.005), were more often non-electively admitted to the pediatric intensive care unit (PICU) (13 versus 4.1%; p = 0.022), and had a longer hospital stay duration (3.7 versus 2.7 days; p = 0.011) than those with ICP. The identified risk factors for respiratory problems were a history of tongue-lip-adhesion (TLA) (p = 0.007) and a preoperative weight of < 8 kg (p = 0.015). Similar risk factors were identified for PICU admission (p = 0.015 and 0.004, respectively).

CONCLUSIONS

The possible risk factors for these outcomes were a low preoperative weight and history of TLA. Closer postoperative surveillance should be considered for patients with these risk factors.

CLINICAL RELEVANCE

Identifying risk factors for respiratory complications could provide clinicians better insight into their patients and allows them to provide optimal care for their patients.

Prenatal Diagnosis of Fetal Micrognathia at 11-20 Weeks of Gestation: A Prospective Observation Study

OBJECTIVE

To prospectively evaluate the prognosis of fetuses diagnosed with micrognathia using prenatal ultrasound screening.

METHODS

Between January 2019 and December 2022, a normal range of IFA to evaluate the facial profile in fetuses with micrognathia in a Chinese population between 11 and 20 gestational weeks was established, and the pregnancy outcomes of fetal micrognathia were described. The medical records of these pregnancies were collected, including family history, maternal demographics, sonographic findings, genetic testing results, and pregnancy outcomes.

RESULTS

Ultrasound identified 25 patients with fetal micrognathia, with a mean IFA value of 43.6°. All cases of isolated fetal micrognathia in the initial scans were non-isolated in the following scans. A total of 78.9% (15/19) cases had a genetic cause confirmed, including 12 with chromosomal abnormalities and 3 with monogenic disorders. Monogenic disorders were all known causes of micrognathia, including two cases of campomelic dysplasia affected by SOX9 mutations and one case of mandibulofacial dysostosis with an EFTUD2 mutation. In the end, 19 cases were terminated, 1 live birth was diagnosed as Pierre Robin syndrome, and 5 cases were lost to follow-up.

CONCLUSION

IFA is a useful indicator and three-dimensional ultrasound is a significant support technique for fetal micrognathia prenatal diagnosis. Repeat ultrasound monitoring and genetic testing are crucial, with CMA recommended and Whole exome sequencing performed when normal arrays are reported. Isolated fetal micrognathia may be an early manifestation of monogenic disorders.

Fetal Profile Markers for the Detection of Robin Sequence in Fetuses with Retrognathia

OBJECTIVE

To determine whether the prefrontal space ratio (PSFR), inferior facial (IFA) and maxilla-nasion-mandible angle (MNM), and the fetal profile line (FPL) are helpful in identifying fetuses with Robin sequence (RS) in cases with isolated retrognathia, and thus better predict the likelihood of immediate need for postnatal respiratory support.

METHODS

This was a retrospective matched case-control study of fetuses/infants with isolated retrognathia with or without RS receiving pre- and postnatal treatment at the University Hospital of Tübingen, Germany between 2008 and 2020. The PFSR, IFA, MNM, and FPL were measured in affected and normal fetuses according to standardized protocols. Cases were stratified into isolated retrognathia and RS.

RESULTS

21 (n=7 isolated retrognathia, n=14 RS) affected fetuses and 252 normal fetuses were included. Their median gestational age at ultrasound examination was 23.6 and 24.1 weeks, respectively. In fetuses with isolated retrognathia and RS, the PSFR, IFA, and FPL were significantly different from the normal population. At a false-positive rate of 5%, the detection rate was 76.2% for the PFSR, 85.7% for the IFA, and 90.5% for both parameters combined. However, all parameters failed to distinguish between isolated retrognathia and RS.

CONCLUSION

PSFR and IFA are simple markers for identifying retrognathia prenatally. However, they are not helpful for the detection of RS in fetuses with isolated retrognathia. Therefore, delivery should take place in a center experienced with RS and potentially life-threatening airway obstruction immediately after birth.

Can Dynamic Magnetic Resonance Images Improve Prenatal Diagnosis of Robin Sequence

BACKGROUND

Robin sequence (RS) is a triad of micrognathia, glossoptosis, and airway obstruction. Prenatal diagnosis of RS improves delivery planning and postnatal care, but the process for prenatal diagnosis has not been refined. The purpose of this study was to determine if dynamic cine magnetic resonance imaging (MRI) can improve the reliability of prenatal diagnosis for RS compared to current static imaging techniques.

MATERIALS AND METHODS

This is a retrospective cross-sectional study including fetuses with prenatal MRIs obtained in a single center from January 2014 to November 2019. Fetuses were included if they: 1) had a prenatal MRI with cine dynamic sequences of adequate quality, 2) were live born, and 3) had postnatal craniofacial evaluation to confirm RS. Patients without postnatal confirmation of their prenatal findings were excluded. The primary predictor variable was imaging type (cine or static MRI). Outcome variables were tongue and airway measurements: 1) tongue height, 2) length and width, 3) tongue shape index, 4) observation of tongue touching the posterior pharyngeal wall, and 5) measurement of oropharyngeal space. All measurements were made independently on the cine images and on static MRI sequences for the same cohort of subjects by a pediatric radiologist. Data were analyzed using paired samples t tests and Fisher exact tests, and significance was set as P < .05.

RESULTS

A total of 11 patients with RS were included in the study. The smallest airway space consistently demonstrated complete collapse on the cine series compared to partial collapse on static images (0 mm vs 1.7 ± 1.4 mm, P = .002). No other imaging variable was statistically significantly different between techniques.

CONCLUSIONS

Cine imaging sequences on prenatal MRI were superior to static images in discerning complete collapse of the smallest airway space, an important marker of RS. This suggests a possible benefit to adding dynamic MRI evaluation for prenatal diagnosis of this condition.

Fetal Micro and Macroglossia: Defining Normal Fetal Tongue Size

OBJECTIVES

Abnormal fetal tongue size is a phenotypic feature of various syndromes including Beckwith-Wiedemann, Pierre-Robin, oromandibular limb hypoplasia, chromosomal aberrations, etc. Current data regarding normal fetal tongue size are limited. Hence, micro/macroglossia are subjectively determined. The aim of the study was to construct a contemporary fetal tongue nomogram and to assess its clinical contribution.

METHODS

A prospective cross-sectional study was performed in well dated, low risk, singleton pregnancies. Fetal tongues were measured by 5 trained sonographers. Highest quality images were selected. Intra- and interobserver variability was assessed. Tongue length, width, area, and circumference 1st to 99th centiles were calculated for each gestational week. Based on the normal tongue size charts, we created a Tongue Centile Calculator.

RESULTS

Over 18 months, 664 tongue measurements were performed. A cubic polynomial regression model best described the correlation between tongue size and gestational age. The correlation coefficient (r² ) was 0.934, 0.932, 0.925, and 0.953 for tongue length, width, area, and circumference, respectively (P < .001). Intra- and interobserver variability had high interclass correlation coefficients (>0.9). Using the new charts, we were able to identify 2 cases of macroglossia, subsequently diagnosed with Beckwith-Wiedemann, and 4 cases of microglossia, 3 associated with Pierre-Robin sequence, and 1 associated with persistent buccopharyngeal membrane.

CONCLUSIONS

We present novel fetal tongue size charts from 13 to 40 weeks of gestation. Clinical application of these nomograms may be beneficial in the prenatal diagnosis of syndromes or malformations associated with abnormal fetal tongue size.

Prenatal diagnosis of micrognathia: a systematic review

Purpose

This systematic review aimed to analyze the characteristics of different diagnostic techniques for micrognathia, summarize the consistent diagnostic criteria of each technique, and provide a simple and convenient prenatal diagnosis strategy for micrognathia.

Methods

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the search was undertaken in three international databases (PubMed, Scopus, and Web of Science). The three reviewers assessed all papers and extracted the following variables: author's name and year of publication, country, study design, number of participants, gestational age, equipment for prenatal examination, biometric parameters related to micrognathia, main results.

Results

A total of 25 articles included in the analysis. Nineteen articles described cross-sectional studies (76 percent), 4 (16 percent) were case-control studies, and 2 (8 percent) were cohort studies. Fifteen studies (60 percent) had a prospective design, 9 (36 percent) had a retrospective design, and one (4 percent) had both prospective and retrospective design. Thirty-two percent of the studies (n = 8) were performed in USA, and the remaining studies were performed in China (n = 4), Israel (n = 3), Netherlands (n = 3), UK (n = 1), France (n = 1), Italy (n = 1), Belgium(n = 1), Germany (n = 1), Spain (n = 1), and Austria (n = 1). The prenatal diagnosis of micrognathia can be performed as early as possible in the first trimester, while the second and third trimester of pregnancy were the main prenatal diagnosis period. The articles that were included in the qualitative synthesis describe 30 biometric parameters related to the mandible.

Conclusion

Of the 30 biometric parameters related to the mandible, 15 can obtain the simple and convenient diagnostic criteria or warning value for micrognathia. Based on these diagnostic criteria or warning value, clinicians can quickly make a preliminary judgment on facial deformities, to carry out cytologic examination to further clarify the diagnosis of micrognathia.

Reference ranges of fetal mandible measurements: Inferior facial angle, jaw index, mandible width/maxilla width ratio and mandible length in Thai fetuses at 15 to 23 weeks of gestation

Objectives

To determine the normal distribution of 1) inferior facial angles (IFA), 2) jaw index, 3) mandible width/maxilla width ratio (MD/MX ratio), and 4) mandible length (ML) in second trimester Thai fetuses.

Methods

A prospective study was performed between April 1 and October 31, 2020, at the Maternal-Fetal Medicine Unit of Songklanagarind Hospital. Transabdominal ultrasonography was performed on Thai singleton pregnant women at 15^0/7 to 23^6/7 weeks of gestation to measure IFA, jaw index, MD/MX ratio and ML. All women received standard antenatal care and were followed up until delivery. The exclusion criteria were multifetal gestation, congenital anomaly, chromosomal abnormality, fetal growth restriction, abnormal amniotic fluid volume, suspected abnormality of fetal mandible, maxilla or jaws based on the proposed criteria from previous studies and suspected neonatal structural or genetic abnormalities postnatally. Quantile regression was used to estimate changes in the median, 5th and 95th percentiles of each parameter across gestational ages and to generate formulas for predicting the 5th percentile value for each parameter.

Results

The results of 291 women were analyzed. Scatter plots and reference ranges of each parameter were generated. IFA, jaw index and ML values significantly increased, while the MD/MX ratio value significantly decreased, with increasing gestational age. The formulas calculated for predicting the 5th percentile value for each parameter were IFA = 55.12 + 0.045*(GA in days—136) jaw index = 37.272 + 0.01693*(GA in days—136) MD/MX ratio = exp(0.027–0.00110*(GA in days—136)) ML = 20.83 + 0.243*(GA in days—136).

Conclusions

The reference ranges and formulas to calculate the 5th percentile values of mandible parameters in Thai fetuses were developed.

Trial registration

This study has been reviewed and approved by the Thai Clinical Trials Registry with identification number TCTR20210602003.

Epidemiology of Rare Craniofacial Anomalies: Retrospective Western Australian Population Data Linkage Study

OBJECTIVE

To describe birth prevalence of rare craniofacial anomalies and associations with antenatal and perinatal factors.

STUDY DESIGN

All live and stillbirths in Western Australia between 1980 and 2010 were identified from the Western Australian Birth Registrations and the Midwives Notification System (also provides information on antenatal and perinatal factors). Rare craniofacial anomalies (craniosynostosis, craniofacial microsomia, and others [Pierre Robin, Van der Woude, and Treacher Collins syndrome]) were ascertained from the Western Australian Register of Developmental Anomalies and linked to other data sources. Trends in prevalence, adjusted for sex and Indigenous status, were investigated by Poisson regression and presented as annual percent change (APC). Strengths of association of related factors were assessed using multivariable log-binomial regression adjusted for sex, Indigenous status, birth year, socioeconomic disadvantage, and remoteness and reported as risk ratios with 95% CIs.

RESULTS

There was a temporal increase in prevalence of metopic synostosis (APC 5.59 [2.32-8.96]) and craniofacial microsomia (Goldenhar syndrome) (APC 4.43 [1.94-6.98]). Rare craniofacial anomalies were more likely among infants born preterm, as twins or greater-order multiples, with growth restriction, to older parents, to mothers undertaking fertility treatments, and with pre-existing medical conditions, specifically epilepsy, diabetes, or hypothyroidism. Prenatal identification of rare craniofacial anomalies was uncommon (0.6%).

CONCLUSIONS

Our findings indicate a steady increase over time in prevalence of metopic synostosis and craniofacial microsomia (Goldenhar syndrome). Possible associations of fertility treatments and pre-existing maternal medical conditions with rare craniofacial anomalies require further investigation.

Mandibular distraction to correct severe non-isolated mandibular hypoplasia: The role of drug-induced sleep endoscopy (DISE) in decision making

OBJECTIVES

In patients with mandibular hypoplasia, mandibular distraction osteogenesis (MDO) aims to relieve tongue-based airway obstruction. Drug-induced sleep endoscopy (DISE) provides a dynamic assessment of the upper airway and visualizes anatomical site and cause of airway obstruction. The aim of this study was to evaluate the effect of MDO on tongue-based airway obstruction found by DISE within a non-isolated patient population with severe upper airway obstruction (UAO). Furthermore, we aimed to assess the additional value of DISE in clinical decision making by correlating DISE findings to functional airway outcomes after MDO.

METHODS

Findings on DISE in children who underwent MDO were retrospectively gathered and evaluated. According to DISE findings, severity of tongue-based obstruction was scored using a 4-step classification similar to the one that is used by Bravo et al.. Intubation conditions were scored according to the Cormack Lehane score (CLS). Pre-and postoperative DISE findings were compared and correlated with functional airway outcomes following MDO.

RESULTS

In 19 out of 28 MDO procedures, both a pre-and postoperative DISE was available. Tongue-based obstruction scores improved in 13 procedures, which correlated to a functional improvement in seven. Postoperative tongue-based obstruction differed significantly between patients with successful MDO and patients treated unsuccessfully (2.00 ((Interquartile range (IQR) 1.00-2.00) vs. 3.00 (IQR 2.00-4.00), p = 0.028), whereas this difference was not significant for the CLS (1.00 (IQR 1.00-1.50) vs. 2.00 (IQR 1.00-4.00), p = 0.066). If no improvement of tongue-based obstruction was seen, MDO is very unlikely to be successful on the functional airway.

CONCLUSIONS

DISE provides information on the site and nature of airway obstruction and can visualize the effect of MDO on the severity of tongue-based airway obstruction. Therefore, it can be of additional value in understanding the differences in functional airway outcomes after MDO and aids in deciding appropriate and targeted treatment. Hence, standardized use of DISE, in addition to the clinical assessment of mandibular position and a polysomnography, during MDO management is highly recommended.

Epidemiology of Pierre-Robin sequence in Europe: A population-based EUROCAT study

BACKGROUND

Pierre Robin sequence (PRS) is a rare congenital anomaly. Respiratory disorders and feeding difficulties represent the main burden.

OBJECTIVE

The aim of this study was to investigate the epidemiology of PRS using a cohort of cases from EUROCAT, the European network of population-based registries of congenital anomalies.

METHODS

We analysed cases of PRS born in the period 1998-2017 collected by 29 population-based congenital anomaly registries in 17 different countries. We calculated prevalence estimates, prenatal detection rate, survival up to 1 week, and proportions of associated anomalies. The effect of maternal age was tested using a Poisson regression model.

RESULTS

Out of 11 669 155 surveyed births, a total of 1294 cases of PRS were identified. The estimate of the overall prevalence was 12.0 per 100 000 births (95% CI 9.9, 14.5). There was a total of 882 (68.2%) isolated cases, and the prevalence was 7.8 per 100 000 births (95% CI 6.7, 9.2). A total of 250 cases (19.3%) were associated with other structural congenital anomalies, 77 cases (6.0%) were associated with chromosomal anomalies and 77 (6.0%) with genetic syndromes. The prenatal detection rate in isolated cases was 12.0% (95% CI 9.8, 14.5) and increased to 16.0% (95% CI 12.7, 19.7) in the sub-period 2008-2017. The prevalence rate ratio of non-chromosomal cases with maternal age ≥35 was higher than in cases with maternal age <25 for total (PRR 1.26, 95% CI 1.05, 1.51) and isolated cases (PRR 1.33, 95% CI 1.00, 1.64). Survival of chromosomal cases (94.2%) and multiple anomaly cases (95.3%) were lower than survival of isolated cases (99.4%).

CONCLUSIONS

This epidemiological study using a large series of cases of PRS provides insights into the epidemiological profile of PRS in Europe. We observed an association with higher maternal age, but further investigations are needed to test potential risk factors for PRS.

Machine Learning Models on ADC Features to Assess Brain Changes of Children With Pierre Robin Sequence

In order to evaluate brain changes in young children with Pierre Robin sequence (PRs) using machine learning based on apparent diffusion coefficient (ADC) features, we retrospectively enrolled a total of 60 cases (42 in the training dataset and 18 in the testing dataset) which included 30 PRs and 30 controls from the Children's Hospital Affiliated to the Nanjing Medical University from January 2017–December 2019. There were 21 and nine PRs cases in each dataset, with the remainder belonging to the control group in the same age range. A total of 105 ADC features were extracted from magnetic resonance imaging (MRI) data. Features were pruned using least absolute shrinkage and selection operator (LASSO) regression and seven ADC features were developed as the optimal signatures for training machine learning models. Support vector machine (SVM) achieved an area under the receiver operating characteristic curve (AUC) of 0.99 for the training set and 0.85 for the testing set. The AUC of the multivariable logistic regression (MLR) and the AdaBoost for the training and validation dataset were 0.98/0.84 and 0.94/0.69, respectively. Based on the ADC features, the two groups of cases (i.e., the PRs group and the control group) could be well-distinguished by the machine learning models, indicating that there is a significant difference in brain development between children with PRs and normal controls.

Prenatal Diagnosis of Robin Sequence: Sensitivity, Specificity, and Clinical Relevance of an Index for Micrognathia

OBJECTIVE

Micrognathia in connection with glossoptosis (called Robin sequence) may lead to life-threatening respiratory problems immediately after birth. An objective detection during prenatal routine ultrasound sonography is possible using an index that relates fetal lower jaw length to femur length or gestational age. The aim of this study was to test the method's sensitivity and specificity and to discuss its predictive power concerning neonatal respiratory insufficiency.

DESIGN

Patients with subjectively identified suspicious signs in the sagittal profile view were included in the study: Two-dimensional serial ultrasound scans of their fetal mandible were used to measure the lower jaw lengths and compare them to predicted values according to an index, derived from 313 healthy fetuses. Follow-up data provided additional information on the clinical appearance of the newborns.

RESULTS

The index showed a high sensitivity: 15 of the 16 cases with a micrognathia were correctly diagnosed (sensitivity of 93.75%). Follow-up data showed that newborns with similar index values differed in terms of their upper airway obstruction and treatment need.

CONCLUSION

Fetal mandibular micrognathia can be objectively evaluated with the help of the index. The method allows an early detection of micrognathia, which helps to take the necessary steps for proper treatment of potential life-threatening respiratory impairment. Observations ranging outside the prediction interval could prompt the ultrasonographer to check for other associated malformations.

Imaging of the Fetal Zygomatic Bone: A Key Role in Prenatal Diagnosis of First Branchial Arch Syndrome

OBJECTIVES

First arch syndromes are congenital defects caused by failure of neural crest cells to migrate into the first branchial arch. First arch syndrome is classified into 2 main clinical manifestations: Treacher Collins syndrome, characterized by bilateral underdevelopment of the zygomatic bones; and Pierre Robin sequence. The aim of this study was to describe the feasibility of visualization of the fetal zygomatic bone and assess its application in cases referred for features suggestive of first arch syndrome.

METHODS

A prospective cohort study was conducted. The feasibility of visualization of the zygomatic bone was performed in 50 sequential fetuses with a normal anatomic scan between 12 and 24 weeks' gestation using 3-dimensional sonography. Following this, cases referred for targeted scans for suspected first branchial arch syndrome were assessed for the presence or absence of the zygomatic bones.

RESULTS

Visualization of the fetal zygomatic bone was feasible in all low-risk cases. Cases referred for targeted scans included 11 isolated cases of micrognathia or retrognathia, 3 cases of microtia, and 3 cases of auricular or facial vestiges. Within this group, the zygomatic bones were visualized in all but 2 cases. No associated extrafacial malformations were detected; therefore, this phenotype was consistent with Treacher Collins syndrome.

CONCLUSIONS

Prenatal imaging of the zygomatic bones offers a clinically based sonographic approach to cases referred for features suggestive of first arch syndrome and enables differentiation between the 2 main clinical manifestations: Treacher Collins syndrome and Pierre Robin sequence.

Quantification of Mandibular Morphology in Pierre Robin Sequence to Optimize Mandibular Distraction Osteogenesis

Background:

Mandibular distraction osteogenesis (MDO) is the primary surgical intervention to treat airway obstruction in Pierre Robin sequence (PRS). Current morphologic studies of PRS mandibles do not translate into providing airway management decisions. We compare mandibles of infants with nonsyndromic PRS to controls characterizing morphological variances relevant to distraction. We also examine how morphologic measurements and airway grades correlate with airway management.

Methods:

Patients with PRS under 2 months old were age and sex matched to controls. Demographic and perioperative data, and Cormack-Lehane airway grades were recorded. Computed tomography scans were used to generate mandibular models. Bilateral condylions, gonions, and the menton were identified. Linear and angular measurements were made. Wilcoxon rank sum and 2-sample t tests were performed.

Results:

Twenty-four patients with PRS and 24 controls were included. Seventeen patients with PRS required MDO. PRS patients had shorter ramus heights (16.7 vs 17.3 mm; P = .346) and mandibular body lengths (35.3 vs 39.3 mm; P < .001), more acute gonial angles (125.3° vs 131.3°; P < .001), and more obtuse intergonial angles (94.2° vs 80.4°; P < .001) compared to controls. No significant differences were found among patients requiring MDO versus conservative management nor among distracted patients with high versus low airway grades.

Conclusion:

Our study examines the largest and youngest PRS population to date regarding management of early airway obstruction with MDO. Our findings indicate that univector mandibular body distraction allows for normalization in nonsyndromic patients with PRS, and airway obstruction management decisions should remain clinical.

Clinical outcomes of prenatal diagnosis of the fetal micrognathia: A case report

RATIONALE

Micrognathia is a subtle facial malformation characterized by a small mandible and receding chin. Fetal micrognathia is often associated with chromosomal abnormalities, skeletal dysplasia, and various syndromes. Once it is dignosised, detailed fetal malformation screening and chromosome examination should be carried out.

PATIENT CONCERN

One pregnant woman with suspicion of fetal micrognathia was referred from her local hospital to our hospital for detailed fetal malformation screening and fetal echocardiography. Examination of the fetus was performed using a two-dimensional and three-dimensional ultrasound probe in multiple planes. The fetus showed micrognathia without glossoptosis with features of the inferior facial angle (IFA) ≤50° and his tongue reached anterior mandibular border box during normal movement.

DIAGNOSES

The fetus was diagnosed as isolated micrognathia prenatally without multisystem abnormalities.

INTERVENTIONS

Amniocentesis was performed and the fetus was found to carry 46XN with 6q14.1 duplication, the significance of which was unclear.

OUTCOMES

The fetus was labored through vagina at 38 weeks gestation. A small soft cleft palate was diagnosed after delivery.

LESSONS

This case suggests that once prenatal diagnosis of the fetal micrognathia has been made, we should carefully examine the presence of fetus's multisystem developmental abnormalities and due consideration should be given for associated soft cleft palate.

Measurement of inferior facial angle and prefrontal space ratio in first trimester fetuses with aneuploidies: a retrospective study

Objective To determine whether the measurement of inferior facial angle (IFA) and prefrontal space ratio (PFSR) in two-dimensional (2D) ultrasound images in the first trimester of pregnancy is reliable and to describe these markers in normal and aneuploid fetuses. Methods IFA and PFSR were measured in stored 2D midsagittal images of 200 normal and 140 aneuploid fetal profiles between 11 + 0 and 13 + 6 weeks of gestation. Limits of agreement (LOAs) and intraclass correlation coefficients (ICCs) for inter- and intraobserver differences were calculated. Results The mean IFA in normal fetuses was 76.5° ± 6.3. Between the two measurement rounds of the same observer, the LOAs were -5.4 to 7.1 (obs. 1) and 7.4 to 8.4 (obs. 2). For IFA measurements by the same observer the ICC was 0.88 (obs. 1) and for measurements by two different observers the ICC was 0.74. The mean PFSR was 0.76 ± 0.40 and the intraobserver LOAs were -0.372 to 0.395 (obs. 1) and -0.555 to 0.667 (obs. 2). For PFSR measurements by the same observer the ICC was 0.89 (obs. 1) and for measurements by two different observers the ICC was 0.65. Among aneuploid fetuses, IFA was below the normal range in one third of the cases with trisomy 18. PFSR was below the 95% prediction limit in 16.2% of fetuses with trisomy 21% and 17.9% of fetuses with trisomy 18. Conclusion IFA can be reliably measured in 2D ultrasound images in the first trimester of pregnancy with a high interobserver agreement and may provide information about retrognathia associated with various syndromes and aneuploidies at early stages of pregnancy.

Can Robin Sequence Be Predicted From Prenatal Ultrasonography?

PURPOSE

Prenatal diagnosis of Robin sequence (RS) could promote safe delivery and improve perinatal care. The purpose of this study was to evaluate the correlation between prenatal ultrasonography (US) and magnetic resonance imaging (MRI) studies for assessing micrognathia to determine if US alone can be used to reliably screen for RS.

MATERIALS AND METHODS

This was a retrospective case-control study of fetuses evaluated in the Advanced Fetal Care Center at Boston Children's Hospital from 2002 to 2017. To be included, 1) prenatal MRI and US must have been performed during the same visit, 2) the infant must have been live-born, and 3) the diagnosis must have been confirmed postnatally. Patients with images of inadequate quality for analysis were excluded. Patients were divided into 4 groups based on postnatal diagnosis: 1) RS (micrognathia, glossoptosis, and airway obstruction) (RS group), 2) micrognathia without RS (micrognathia group), 3) cleft lip and palate (CLP) without micrognathia (CLP group), and 4) gestational age-matched controls with normal craniofacial morphology (control group). The inferior facial angle (IFA) was measured using both imaging modalities and compared. Receiver operating characteristic curves were applied to identify a threshold for the diagnosis of RS from US. The sensitivity, specificity, positive predictive value, negative predictive value, and odds ratio were calculated.

RESULTS

A total of 94 patients were included (mean gestational age at imaging, 24.9 ± 5.2 weeks), with 25 in the RS group (26.6%), 29 in the micrognathia group (30.9%), 23 in the CLP group (24.5%), and 17 in the control group (18.1%). The IFA was significantly smaller in the RS group than in all other groups on both US and MRI (P < .001). A moderate correlation was found between IFA measurements on US and MRI (intraclass correlation coefficient, 0.729). An IFA threshold on US of 45.5° maximized sensitivity (84%) and specificity (81%) for the diagnosis of RS.

CONCLUSIONS

We suggest incorporating the IFA into routine prenatal US and referring patients for confirmatory MRI when the US IFA is lower than 45.5°.

Prenatal diagnosis of micrognathia in 41 fetuses: Retrospective analysis of outcome and genetic etiologies

Fetal micrognathia can be detected early in pregnancy. Prognosis of micrognathia depends on the risk of respiratory distress at birth and on the long-term risk of intellectual disability. The purpose of this study was to evaluate the long-term prognosis of fetuses with prenatal diagnosis of micrognathia by estimating the prevalence and the severity of confirmed genetic diagnosis in our cohort. Our retrospective study included 41 fetuses with prenatal diagnosis of micrognathia referred to the multidisciplinary centers for prenatal diagnosis in Nice and Marseille, France, between 2006 and 2016. Fetal micrognathia was associated with cleft palate in 27 cases. A genetic cause was confirmed in 21 cases (67%). A chromosomal abnormality was present in 12 cases, including three copy-number variations diagnosed by array CGH. Monogenic disorders were identified in nine cases, most often after birth. Fetuses with family history of micrognathia or Pierre Robin sequence had a favorable outcome. Prognosis was good for the fetuses without associated findings and normal chromosomal analysis, with the exception of one case with a postnatal diagnosis of mandibulofacial dysostosis with microcephaly. Prognostic was poor for the fetuses with additional ultrasound anomalies, as only 5 out of 28 children had a good outcome. Prenatal diagnosis of micrognathia is an indicator of a possible fetal pathology justifying multidisciplinary management. Our study confirms the necessity of performing prenatal array CGH. Use of high-throughput gene sequencing in prenatal period could improve diagnostic performance, prenatal counseling, and adequate postnatal care.

The Tübingen palatal plate approach to Robin sequence: Summary of current evidence

Various treatments, many of them considerably invasive, are currently applied to infants with Robin sequence (RS) and accompanying upper airway obstruction (UAO). We present a narrative review of our data on the Tübingen palatal plate (TPP) which show the following: a) in a randomized trial, the TPP was superior to a sham procedure in alleviating UAO; b) children treated with the TPP in infancy showed an intellectual development within the reference range; c) prone positioning is no alternative, as it is ineffective and associated with an increased risk of sudden death; d) the TPP reduces the mixed-obstructive apnea index to near-normal values, both in isolated and most (83%) syndromic RS, e) of 443 infants (129 syndromic) treated with the TPP in our center, 23 (5%) ultimately received a tracheostomy (all with syndromic RS), f) recent data suggest that the TPP may induce mandibular catch-up growth, g) the TPP may also help to reduce respiratory complications following cleft closure in RS, and h) TPP treatment is applied by various centers around the world, although it is unclear if its effectiveness is invariably controlled by endoscopy and sleep studies, although both are necessary. Given these data from peer-reviewed studies, it may be questioned whether the "First do no harm" principle is always adhered to when subjecting RS infants to more invasive procedures such as mandibular distraction osteogenesis or tongue-lip adhesion.

The location of the fetal ears: A hint for prenatal diagnosis of agnathia-otocephaly complex

Otocephaly is an extremely rare lethal congenital anomaly characterized by the absence or underdevelopment of the mandible. The clinical presentation is variable. Some cases may present with severe micrognathia as the only anomaly seen prenatally. The key to early diagnosis is careful assessment of the location of the fetal ears on 2D ultrasound examination.

Peripartum Management of Neonatal Pierre Robin Sequence

Pierre Robin sequence (PRS) is a congenital condition characterized by the presence of micrognathia, glossoptosis, and cleft palate. PRS has varying effects on airway patency and feeding ability and thus has a broad range of management options. The purpose of this article is to describe the nature of the background of the condition and address the previous and current trends in diagnosis and management of PRS.

Is Amniotic Fluid Level a Predictor for Syndromic Diagnosis in Robin Sequence?

OBJECTIVE

The purpose of this study was to determine whether gestational amniotic fluid level abnormalities were associated with postnatal syndromic status in a series of patients with Robin sequence (RS).

DESIGN

Retrospective study of participants with RS at Boston Children's Hospital from 1967 to 2017. Participants were divided into syndromic and nonsyndromic groups. The primary predictor variable was postnatal syndromic diagnosis (yes/no). Additional predictor variables included gestational age at birth, birthweight, sex, presence of cleft palate, and other congenital anomalies. The primary outcome variable was amniotic fluid level (normal, oligohydramnios, or polyhydramnios). Descriptive statistics were computed and logistic regression was used to analyze amniotic fluid level as a predictor for syndromic diagnosis. Statistical significance was set at P < .05.

RESULTS

Sixty-five (54%) syndromic and 56 (46%) nonsyndromic RS participants were included. An abnormal amniotic fluid level was seen significantly more frequently in the syndromic group (49.2% vs 25.0%; P = .001). Abnormal amniotic fluid level was associated with a 2.9-fold increased likelihood of a syndromic diagnosis (P = .007). Polyhydramnios, which was seen more frequently than oligohydramnios, predicted a 4.18 times increased likelihood of a syndromic diagnosis (P = .003).

CONCLUSIONS

Abnormal amniotic fluid level, particularly polyhydramnios, is associated with an increased likelihood of a syndromic diagnosis in patients with RS.

The ontogeny of Robin sequence

The triad of micrognathia, glossoptosis, and concomitant airway obstruction defined as "Robin sequence" (RS) is caused by oropharyngeal developmental events constrained by a reduced stomadeal space. This sequence of abnormal embryonic development also results in an anatomical configuration that might predispose the fetus to a cleft palate. RS is heterogeneous and many different etiologies have been described including syndromic, RS-plus, and isolated forms. For an optimal diagnosis, subsequent treatment and prognosis, a thorough understanding of the embryology and pathogenesis is necessary. This manuscript provides an update about our current understanding of the development of the mandible, tongue, and palate and possible mechanisms involved in the development of RS. Additionally, we provide the reader with an up-to-date summary of the different etiologies of this phenotype and link this to the embryologic, developmental, and genetic mechanisms.

In Utero Glossoptosis in Fetuses With Robin Sequence

Objective:

Glossoptosis causes airway obstruction in patients with Robin sequence (RS), but little is known about the in-utero tongue. The purpose of this study was to assess shape and position of the fetal tongue on prenatal magnetic resonance imaging (MRI) to determine if this is predictive of postnatal RS.

Design:

Retrospective case-control study including fetuses with prenatal MRIs performed from 2002 to 2017. Inclusion criteria were (1) prenatal MRI of adequate quality, (2) live born and evaluated postnatally for craniofacial findings. Subjects were divided into groups based on postnatal findings: (1) RS, (2) micrognathia without RS, and (3) a gestational-age-matched control group with normal craniofacial morphology. Outcome variables were based on the prenatal MRI and included fetal tongue height, length, and width, tongue shape index (TSI, ratio of height to length), and observation of tongue touching the posterior pharyngeal wall.

Results:

A total of 116 subjects with mean gestational age at MRI of 25.6 ± 5.1 weeks were included: RS, n = 27 (23%); micrognathia, n = 35 (30%); control, n = 54 (47%). Tongue length was significantly shorter ( P = .009) and TSI was significantly larger in the RS group ( P < .0001). The tongue touched the posterior pharyngeal wall in 5 (19%) of the RS group and in no subjects in the other groups ( P < .0001).

Conclusion:

In utero tongue shape and position were significantly different in fetuses with postnatal RS compared to those with isolated micrognathia and controls. Prenatal MRI tongue characteristics may be predictors for postnatal RS.

Micrognathia and Oropharyngeal Space in Patients With Robin Sequence: Prenatal MRI Measurements

PURPOSE

Micrognathia is the initiating feature of Robin sequence (RS) and leads to airway obstruction. Prenatal identification of micrognathia is currently qualitative and has not correlated with postnatal findings in previous studies. Oropharyngeal airway space has not been evaluated prenatally. The purposes of this study were to 1) quantitate mandibular characteristics and oropharyngeal size at prenatal magnetic resonance imaging (MRI) and 2) identify differences in fetuses with postnatal RS compared with those with micrognathia (without RS) and normal controls.

MATERIALS AND METHODS

This is a retrospective case-control study of fetuses with prenatal MRIs performed from 2002 through 2017 who were live born and evaluated postnatally for craniofacial findings. Postnatal findings were used to divide patients into 3 groups: 1) RS (micrognathia, glossoptosis, and airway obstruction), 2) micrognathia without RS ("micrognathia"), and 3) a gestational-age matched control group with normal craniofacial morphology ("control"). Inferior facial angle (IFA), jaw index, and oropharyngeal space (OPS) were calculated and compared among groups.

RESULTS

Of 116 patients in this study, 27 had RS (23%), 35 had micrognathia (30%), and 54 were control subjects (47%). IFA, jaw index, and OPS were statistically significantly smaller in the RS group compared with the comparison groups (P < .0001).

CONCLUSIONS

Prenatal MRI measurements of micrognathia and OPS are considerably different in patients with RS compared with other groups, including those with micrognathia alone. These measurements might serve as reliable prenatal predictors of RS.