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.

The added value of detailed early anomaly scan in fetuses with increased nuchal translucency.

OBJECTIVE: This study aims to assess the utility of a detailed early fetal anatomy scan prior to karyotyping in the management of pregnancies with an increased nuchal translucency (NT). METHODS: The study included fetuses with NT above the 99th centile. These women were offered the option of an early detailed fetal anatomy scan prior to genetic evaluation. The presence or absence of major sonographic findings was analyzed for its predictive value for fetal aneuploidy. RESULTS: An increased NT >99th centile was detected in 43 fetuses (1.8%). Mean NT was 4.5 mm (range 3.4-9.0), and gestational age at the early fetal anatomy survey was 12.4 weeks (12-13.6). Major sonographic findings were present in 30 fetuses (69.8%); 24 of them underwent karyotyping, and it was abnormal in 14. Among the 13 fetuses without major sonographic findings, 12 had normal karyotype results, and 1 had aneuploidy, yielding a positive predictive value of 58.3% of early fetal anatomy scan for abnormal karyotype results. Multivariate logistic regression analysis showed that the presence of major sonographic findings was as an independent predictor of fetal aneuploidy (adjusted odds ratio 8.15). CONCLUSION: A detailed early anatomy scan upon detection of increased NT has an important value in the prediction of fetal aneuploidy. © 2016 John Wiley & Sons, Ltd.

Prenatal sonographic features of triploidy at 12-16 weeks.

OBJECTIVE: The purpose of our study was to describe the sonographic appearance of triploidy in early pregnancy. METHODS: We report the sonographic characteristics of a cohort of fetal triploid cases detected at targeted ultrasonographic vaginal examinations between 12 and 16 weeks of gestation from 2008 to 2014. Indications for fetal karyotype following ultrasound were maternal request, advanced maternal age, increased nuchal translucency, and/or fetal abnormalities. RESULTS: Triploidy was detected in 25 cases during the 6 years of the study period with an estimated incidence of ~1 in 5000 pregnancies. Four cases had molar changes in the placenta. Among the remaining 21 cases, a consistent sonographic pattern was noted, which included the combination of asymmetric growth restriction with abdominal circumference lagging 2 weeks behind head circumference in 21/21, oligohydramnios in 20/21, abnormal posterior fossa or enlarged fourth ventricle in 20/21, and absent gall bladder in 17/21. Other findings present in more than 50% of cases included cardiac (70%) and renal (55%) abnormalities, clenched hands (55%), and hypoplastic lungs (67%). CONCLUSION: Fetal triploidy can manifest at 12-16 weeks with molar changes in the placenta or with a cluster of unusual sonographic findings whose presence should prompt appropriate testing for diagnosis in early pregnancy. © 2016 John Wiley & Sons, Ltd.

Sonographic Evaluation of the Fetal Thymus Using the Thy-Box Technique Between 13 and 16 Weeks' Gestation.

OBJECTIVES: The purposes of this study were to assess the feasibility of fetal thymus measurement between 13 and 16 weeks' gestation, to evaluate the potential difference using color Doppler sonography with the thy-box technique, and to construct normal percentile ranges. METHODS: This retrospective study included 287 healthy singleton pregnancies. The fetal thymus was shown in an axial plane of the upper mediastinum. Color Doppler imaging was applied to outline the thy-box: ie, the area between the brachiocephalic artery posteriorly and internal mammary arteries laterally. Measurements of the lateral and anteroposterior diameters of the thymus with and without color Doppler imaging were compared. RESULTS: The thymus was shown in 95% of the cases (273 of 287) between 13 and 16 weeks' gestation. The mean lateral thymus diameter ± SD with color Doppler imaging (5.30 ± 0.7 mm) was significantly longer in comparison to the measurement without color Doppler imaging (5.06 ± 0.8 mm; P < .001), whereas the anteroposterior diameter was significantly shorter (3.19 ± 0.9 versus 3.26 ± 0.8 mm; P = .044). Normal percentiles of thymus measurements for gestational age were constructed. CONCLUSIONS: The fetal thymus can be clearly and accurately shown as early as 13 weeks' gestation by using the thy-box. Measurements with color Doppler imaging were significantly different from those without and hence are preferable, as color Doppler imaging can delineate the thymus borders more accurately.

Umbilical vein insertion into the inferior vena cava: an ominous sign of chromosomal abnormalities?

This series describes the sonographic characteristics and pregnancy outcomes of fetuses with abnormal insertion of the umbilical vein (UV) into the inferior vena cava (IVC). We conducted a retrospective study that described the sonographic features of 6 patients who underwent a routine anatomic scan during early pregnancy. Six patients had a diagnosis of abnormal insertion of the UV to the IVC; in 3, the diagnosis was made at 12 weeks' gestation. Cardiac anomalies were detected in 3 patients, including ventricular septal defects, pericardial effusion, tricuspid and mitral regurgitation, and an aberrant right subclavian artery. Four had noncardiac anomalies, including cystic hygroma and skeletal, brain, and abdominal anomalies. Only 1 fetus who presented with UV insertion into the IVC as an isolated finding had a normal karyotype, resulting in term vaginal delivery. Four other patients had chromosomal abnormalities, including trisomies 13 and 21, Turner mosaicism of 45,XO/46,XY, and Robertsonian translocation, and 1 patient terminated the pregnancy without a karyotype evaluation. Abnormal insertion of the UV into the IVC with agenesis of the ductus venosus can be seen as early as the first trimester. When detected, a detailed anatomic examination should be performed, as well as a fetal karyotype evaluation. Isolated cases of insertion of the UV into the IVC at a position lower than usual may have a good prognosis.

Sonographic examination of the fetal vermis: tricks for obtaining the narrow midline target with 3-dimensional volume contrast imaging in the C plane.

Prenatal imaging of the fetal cerebellar vermis is challenging even for experienced examiners. We found that by aiming the ultrasound beam through the mastoid fontanel and then rotating the data set in a multiplanar reconstruction and applying volume contrast imaging in the C plane, we were consistently able to obtain images of the vermis in the standard midsagittal plane. Images of the fetal vermis suitable for morphologic evaluation were obtained in 408 of 414 cases (98.5%) at gestational ages of 18 weeks to 31 weeks 6 days; the examination time was only minimally increased.

The "lasso sign": an early sonographic sign of posterior meningocele.

Posterior meningocele is an uncommon form of spina bifida. We present a case of unique posterior meningocele diagnosed at the early second trimester anatomical scan using 2D and 3D ultrasound. The sonographic appearance resembled "lasso". The prenatal follow-up was uneventful, with no demonstration of tethered cord. Clinical, neurological and radiological examinations following delivery and at the age of four months were unremarkable.

Fetal brain asymmetry: in utero sonographic study of normal fetuses.

OBJECTIVE: The objective of the study was to evaluate the magnitude of normal fetal brain asymmetry. STUDY DESIGN: This was a prospective study. Normal fetuses between 19-28 weeks of gestation were studied. The cerebral atria, occipital cortex, and hemispheres in both sides were measured. The difference between each side was evaluated and was correlated with sex, head biometry, and estimated weight. RESULTS: Four hundred six fetuses were studied. Mean atrial width was larger in the males and on the left side (5.2% and 6.5%, respectively). Mean cortical width was 2.6% larger in males but 5.5% thinner on the left side. Mean hemisphere width was larger in males and on the left side (2.3% and 1.5%, respectively). The atria and the cortex presented an inverse relationship regarding fetal growth parameters. CONCLUSION: Brain asymmetry represents normal fetal brain developmental phenomena. It is sex dependent and lateralized in most cases to the left. Lateralization was more accentuated in males.

Isolated fetal umbilical vein varix--prenatal sonographic diagnosis and suggested management.

OBJECTIVE: To present our experience with fetuses with umbilical vein varix (UVV), to investigate possible risk factors and to suggest a management scheme of evaluation. STUDY DESIGN: A study of 14 pregnancies complicated with isolated UVV was performed. Data collected included sonographic characteristics of the UVV, pregnancy outcome including induction of labour, mode of delivery, birthweight, and neonatal complications. RESULTS: UVV was diagnosed at a median gestational age of 27.5 weeks' gestation (range: 22-34 weeks). The average diameter of the UVV at diagnosis was 10.6 mm (range: 8-15 mm), and the maximal diameter during follow-up was 12.8 mm (range: 10-18 mm). The median gestational age at delivery was 36.1 weeks (range: 34-40 weeks), with an average birthweight of 2834 g (range: 1725-3715 g). Five women underwent emergent cesarean section. In fetuses with turbulent flow in the UVV there was a tendency to larger maximal sizes of the UVV, earlier gestational age at delivery and smaller birthweight. There were no cases of fetal or neonatal demise. CONCLUSIONS: We suggest that fetuses with UVV should be followed weekly from diagnosis to 28 weeks, and twice a week afterwards. Induction of labour should be considered at 36-37 weeks' gestation or at signs of fetal distress.

Three-dimensional ultrasonography of the fetal vermis at 18 to 26 weeks' gestation: time of appearance of the primary fissure.

OBJECTIVE: The purpose of this study was to establish the normality of the fetal vermis, ie, the time of appearance of the primary fissure, as well as its measurements between 18 and 26 weeks' gestation, using 3-dimensional (3D) ultrasonography. METHODS: A prospective cross-sectional study of normal singleton pregnancies was conducted. Examinations were performed with high-resolution transabdominal ultrasonography using the axial plane in 173 fetuses between 18 and 26 weeks' gestation. Postprocessing measurements of the fetal vermis were done with 4-dimensional software using static volume contrast imaging and tomographic ultrasound imaging in the C-plane. Detection of the primary fissure was evaluated in all cases, and the time of appearance was documented. RESULTS: Adequate vermis measurements were obtained in 173 fetuses. Vermian length as a function of gestational age was expressed by regression equations, and the correlation coefficients were found to be highly statistically significant (P < .001). The normal mean +/- 2 SD for each gestational week was defined. The primary fissure was observed at 24 weeks' gestation in all cases, at 22 weeks in 94% of cases, and as early as 18 weeks in 40%. CONCLUSIONS: This 3D study documents the appearance of the primary fissure and presents the normal range of vermian measurements, confirming normal development of the fetal vermis starting as early as 18 weeks' gestation. It also shows an easy method for visualizing the vermis with 3D ultrasonography at every gestational week regardless of fetal presentation.

Development of the fetal spinal cord: time of ascendance of the normal conus medullaris as detected by sonography.

OBJECTIVE: The purpose of this study was to perform high-resolution sonographic examinations to determine the normal anatomic relationship of the conus medullaris (CM) of the spinal cord with the vertebral column during different stages of gestation. METHODS: In this prospective study, fetal sonographic evaluations were performed between 13 and 40 weeks' gestation. Transvaginal probes (7.5-8 MHz) or abdominal probes (5-8 MHz) were used, depending on gestational age and position of the fetus. The CM was located in coronal longitudinal sections. The positions of the kidneys and lumbosacral junction and the origin of the ribs determined the location of the vertebrae. The locations of the CM were divided into 5 groups according to their positions relative to the vertebrae. RESULTS: A total of 110 fetuses between 13 and 40 weeks' gestation were studied. Between 13 and 18 weeks' gestation, the CM was situated at the level of the L4 vertebra, or more caudally, in 100% of the fetuses. At term, all fetuses showed the CM above L2. A distinct ascent of the CM was detected between 13 and 40 weeks' gestation. The results were statistically significant (P < .0001). CONCLUSIONS: A distinguishable ascent of the CM in relation to the vertebral column during fetal life was detected.

The fetal mandible: an in utero sonographic evaluation between 11 and 31 weeks' gestation.

OBJECTIVE: To construct a growth chart of the mandible throughout gestation. METHODS: A prospective cross-sectional study of normal singleton pregnancies was conducted. Measurements of the fetal mandibular transverse and antero-posterior diameters were performed with high-resolution transvaginal and transabdominal ultrasonography in 490 pregnant women with singleton low-risk pregnancies between 11 and 31 weeks' gestation. RESULTS: The mandibular transverse and antero-posterior diameters were recorded by week of gestation and the ratio was calculated: mandibular ratio (MR) = 1.7759 - 0.01047 x gestational week. There was a negative linear correlation (-1.047%) for each incoming week of gestation. Normal values (+/-1SD and 2SD) were established. CONCLUSION: The present data provides a normal range of fetal mandibular diameters during normal pregnancies and introduces a new parameter, the mandibular ratio, for the intrauterine assessment of the fetal mandibular development.

Ultrasonographic diagnosis of glossoptosis in fetuses with Pierre Robin sequence in early and mid pregnancy.

OBJECTIVE: This study was undertaken to describe the sonographic features of fetal glossoptosis in the Pierre Robin sequence. STUDY DESIGN: Fetal sonography was prospectively performed in 8000 consecutive pregnancies at 14 to 24 weeks' gestation. In addition we retrospectively reevaluated ultrasound recordings of 4 fetuses from other hospitals, in which the diagnosis of Pierre Robin sequence was overlooked at 22 weeks' gestation. Glossoptosis was defined as a posteriorly displaced tongue that never reached the anterior mandibular alveolar ridge while watching the fetal profile. Micrognathia, which is a component of the sequence, was subjectively defined. RESULTS: Glossoptosis with micrognathia was detected in 2 fetuses in the prospective group at 14 and 15 weeks' gestation. Both pregnancies were terminated; the diagnosis was confirmed in 1 case where postmortem examination was performed. There were no false-negative diagnoses in the other 7.998 fetuses. Glossoptosis and micrognathia were observed in the 4 retrospective cases. CONCLUSION: Sonographic identification of glossoptosis with fetal micrognathia suggests the possibility of Pierre Robin sequence.

The influence of prothrombotic polymorphisms and obstetrical and medical variables on the length of secondary postpartum hemorrhage.

OBJECTIVE: To determine if the presence of prothrombotic polymorphisms, such as factor V G1691A (factor V Leiden) or factor II G20210A, affect the length of secondary postpartum bleeding. METHODS: We conducted a prospective and blind study that enrolled primiparous healthy women following singleton pregnancy. Whole blood was taken for determining the presence of factor V G1691A or prothrombin G20210A by PCR and specific restriction enzymes. RESULTS: We enrolled 638 women, of whom 524 had vaginal delivery, 34 had planned cesarean delivery, and 80 had emergency cesarean delivery. Seventy-nine of 524 women with vaginal delivery required vacuum, 19 women needed forceps, and 2 women required both vacuum and forceps. Seventy parturients had prothrombotic polymorphisms: 31 were heterozygote to factor V G1691A, 34 were heterozygote to prothrombin G20210A, and 1 was homozygote for the mutation. Another 4 women had both mutations. Women who gave birth by planned cesarean deliveries bled 4.9 days longer on average than women who gave birth vaginally or had emergency cesarean delivery (p = 0.03), after adjustment for length of pregnancy. The weight of the newborn and the length of the pregnancy affected the duration of bleeding. The presence of prothrombotic polymorphisms did not affect the duration of postpartum bleeding. CONCLUSIONS: The duration of secondary postpartum hemorrhage is related to length of pregnancy, neonate weight, and planned cesarean delivery but is not affected by the presence of factor V G1691A or prothrombin G20210A mutation in the primiparous women.

The common prothrombotic factors in nulliparous women do not compromise blood flow in the feto-maternal circulation and are not associated with preeclampsia or intrauterine growth restriction.

OBJECTIVE: In this study we evaluated the associations between common prothrombotic factors and increased blood flow resistance in the feto-maternal circulation, intrauterine growth restriction, small for gestational age, or preeclampsia. STUDY DESIGN: A prospective study was conducted in healthy nulliparous women with spontaneous singleton pregnancy. Blood was tested for the common prothrombotic factors, i.e., factor V Leiden, factor II G20210A, methylenetetrahydrofolate reductase C677T, anticardiolipin, and lupus anticoagulant. Blood flow resistance in the uterine, placental, and umbilical arteries were assessed by multigate Doppler and compared between women with and without prothrombotic factors. The maternal, fetal, and neonatal clinical courses were also compared among these subgroups. RESULTS: Prothrombotic factors were detected in 191 of 637 (30%) subjects. No significant difference in resistance to blood flow in the feto-maternal unit was discernible between women with and without prothrombotic factors. Pregnancy-induced hypertension or preeclampsia occurred in 10 of 191 (5.2%) and in 19 of 446 (4.3%) of women with and without a prothrombotic factor respectively ( P = .59). Intrauterine growth restriction was detected at 31 weeks in 13 of 164 (7.9%) and in 42 of 377 (11.1%) fetuses of women with and without a prothrombotic factor ( P = .26), and small for gestational age at delivery was observed in 19 of 187 (10.2%) and in 41 of 413 (9.9%) of mothers with and without prothrombotic markers, respectively. CONCLUSION: The presence of prothrombotic factors in healthy nulliparous women does not compromise blood flow in the feto-maternal unit, nor is it associated with preeclampsia, intrauterine growth restriction, or small for gestational age .

Prenatal sonographic diagnosis of hemivertebra.

OBJECTIVE: To describe our experience in prenatal diagnosis of hemivertebra. METHODS: This is a case series of patients referred to our tertiary medical center over a 3-year period. All fetuses were scanned by high-resolution real-time scanners. The apparent vertebral anomaly was assessed in a real-time manner by a joint team of obstetricians, sonographers, and pediatric orthopedic surgeons. A complete anomaly survey of other fetal organs was performed on each fetus. All patients were given proper counseling by the same joint team. All patients had detailed obstetric and neonatal follow-up. Prenatal sonograms, neonatal medical records, and clinical courses were evaluated retrospectively. RESULTS: During the 3 years, 6 cases of hemivertebra were identified in our department. Gestational age at diagnosis was 14 to 23 weeks. Two patients had conception by assisted reproductive technology. Associated anomalies included VATER syndrome (vertebral defects, imperforate anus, tracheoesophageal fistula, and radial and renal dysplasia), gastroschisis, and pyelectasis. Outcomes in fetuses without major associated anomalies were fair. CONCLUSIONS: Diagnosis of isolated hemivertebra might be associated with a favorable outcome. The 3 key factors in achieving an optimal spine at maturity, early diagnosis, anticipation, and prevention of deterioration, might be enhanced by our joint multidisciplinary approach to the diagnosis of skeletal anomalies.

The three-vessel and tracheal view of the fetal heart: an in utero sonographic evaluation.

OBJECTIVES: To establish a nomogram for fetal cardiac three-vessel view diameter changes during gestation. METHODS: The study is a prospective cross-sectional evaluation of 338 male and female fetuses between 14 and 38 weeks of normal singleton pregnancies. Measurements of fetal pulmonary artery, aorta and superior vena cava diameters, performed on a transverse view of the upper mediastinum were conducted using transvaginal ultrasonography between 14 to 18 weeks and transabdominal after 19 weeks' gestation. RESULTS: Adequate measurements of the three cardiac vessels were obtained in 338 fetuses. The regression equations for vessel diameters modeled as function of gestational age were pulmonary artery diameter (mm) = -2.275 + 0.273 x gestational age (week), aorta diameter (mm) = -1.77 + 0.227 x gestational age (week), and SVC diameter (mm) = -0.98 + 0.142 x gestational age (week). The correlation coefficients between gestational age and the diameter of the vessels were, r = 0.93, r = 0.93 and r = 0.86 for pulmonary artery, aorta and SVC respectively (all found to be highly statistically significant, p < 0.0001). The normal mean and 90% prediction limits were defined. CONCLUSION: Our data present the normal range of fetal heart three-vessel diameters during gestation. They may allow intrauterine assessment of their development and an adjunct in the detection and evaluation of great vessel pathology.