Sonographic findings of transient marked proximal bowel dilatation in a growth-restricted fetus at 35 weeks' gestation.

Etiologies underlying the relatively infrequent third-trimester sonographic depiction of dilated fetal bowel include (functional or mechanical) bowel obstruction, intestinal atresia, volvulus, annular pancreas, intestinal malrotation, intussusception, gastrointestinal duplications, cystic fibrosis-associated meconium ileus, congenital chloride diarrhea, microvillus inclusion disease, intestinal neuronal dysplasia, and meconium plug syndrome. Fetal bowel obstruction may be associated with aneuploidy (mostly Trisomy 21 in association with esophageal or duodenal atresia), and rarely select microduplications or deletions. We present unusual sonographic findings associated with transient marked proximal fetal bowel dilatation in association with concurrent development of oligohydramnios, in a growth-restricted fetus at 35 weeks' gestation. This case supports that upon observation of dilated loops of fetal bowel, while not negating the potential need for delivery secondary to potential bowel compromise, consideration should be given for observation in anticipation of potential spontaneous resolution of this condition, especially among growth-restricted fetuses with decreased amniotic fluid volume in prematurity.

Prenatal sonographic findings of prominent fetal tricuspid annulus: A case report.

The tricuspid valve positioned between the right atrium and right ventricle is composed of 3 leaflets (anterior, posterior, and septal) anchored by a collagenous fibrous annulus, a saddle-shaped, oval structure, providing a firm yet dynamic structural support for the tricuspid valve. The annulus is considered to separate between the right atrium and right ventricle. Structural anomalies of the fetal tricuspid valve are rare and include Ebstein's anomaly, tricuspid atresia, partial absence, unguarded tricuspid orifice (absent leaflets) cleft, double orifice, bicuspid valve and Uhl anomaly (absence of the right ventricular myocardium with an apposing endocardium and epicardium). We present an unusual case in which a prominent peripheral circular structure was noted above the periphery of the fetal tricuspid valve at 31 weeks' gestation. Inflow across the tricuspid valve was unimpaired, with no tricuspid regurgitation. The right atrium appeared normal with a normal functioning foramen ovale, and the entire fetal cardiac anatomy and function were normal with no signs of congestive cardiac failure or fetal hydrops. The prominent non-obstructing circular structure in immediate proximity to the tricuspid valve leaflets was considered to represent a prominent tricuspid annulus. An appropriate for gestational age fetus was delivered at term and neonatal echocardiography was normal. This case emphasizes that normal variations in fetal anatomical structures should always be considered and specifically that unimpaired inflow across the tricuspid valve in diastole is key upon encountering an unusually prominent fetal tricuspid annulus, which may be noted at a considerable distance above the tricuspid leaflets within the right atrium.

Sonographic findings of complete tubal abortion.

Ectopic pregnancies, implantation of a fertilized ovum in any location other than within the endometrial cavity, occur in 1-2% of all pregnancies. Despite current enhanced early diagnosis enabled by serum beta-human choriogonadotropin (hCG) levels and high-resolution ultrasound, this clinical entity continues to account for between 2.7 and 6% of all maternal deaths. The most common site of ectopic implantation is the Fallopian tube (>90% of cases), and less commonly in previous Cesarean scar, ovary, cervix, or the abdomen. Complete tubal abortion refers to a tubal pregnancy having been expelled from the distal portion of the Fallopian tube into the peritoneal cavity and may be associated with either considerable hemorrhage, spontaneous resolution, or rarely serve as an initial nidus for an abdominal pregnancy. We present unusual sonographic findings of a complete tubal abortion in a patient with minimal symptomology.

Extensive fundal placenta accreta spectrum (PAS) in a nulliparous patient with an unscarred uterus and systemic lupus erythematosus (SLE) necessitating cesarean hysterectomy at delivery.

Placenta accreta spectrum (PAS) defined by various degrees of abnormally invasive placentation is strongly associated with severe maternal morbidity and maternal mortality, mainly reflecting maternal hemorrhage. Predisposing factors for this condition include: multiparity, placenta previa, previous uterine surgeries (previous curettage, cesarean delivery, and myomectomy), smoking and previous PAS. Prenatal sonographic findings associated with PAS include the presence of placenta previa, loss of the hypoechoic retroplacental sonolucency, myometrial thinning, interruption of the irregularity of the bladder wall, excessive vascularity of the uterovesical plane, placental lacunae, increased placental vascularity, bridging vessels with vascularity extending from the placental bed across the uterine wall into the bladder or other pelvic organs. PAS is very rare among nulliparous patients, especially those without previous uterine surgery. We describe an unusual case of PAS in a nulliparous patient with an unscarred uterus and systemic lupus erythematosus in whom a fundal placenta with PAS and thinned and areas of absent myometrium suspected at midtrimester sonography, sustained uterine atony and severe hemorrhage at delivery, necessitated massive blood transfusion and subtotal hysterectomy. Both mother and infant did well. Pathology confirmed PAS and marked uterine thinning. Although PAS most commonly is associated with placenta previa and the presence of previous cesarean delivery, this case emphasizes the need for alertness of at times subtle prenatal sonographic findings of PAS irrespective of placental location even among nulliparous patients, especially those with systemic lupus erythematosus.

First-trimester septated cystic hygroma, marked non-immune fetal hydrops, 45,X and coarctation of the aorta with neonatal survival.

Marked first-trimester nonimmue hydrops fetalis and 45,X with neonatal survival.

Reverse diastolic flow of the fetal middle cerebral artery associated with placental chorangiomatosis and asymptomatic concealed placental abruption.

Reverse diastolic flow of the fetal middle cerebral artery is a rare, yet ominous finding which has been associated with adverse perinatal outcomes including: intracranial hemorrhage, growth restriction, fetal-maternal hemorrhage, severe anemia, hydrops, hepatic anomaly, subsequent stillbirth, and early neonatal death. We report a case in which following notation of a nonreassuring fetal heart rate at 32 weeks' gestation, sonographic documentation of persistent reverse diastolic flow of the fetal middle cerebral artery was noted in association with sonographic findings of vascular placental dysmorphology and an asymptomatic concealed placental abruption. Subsequent fetal heart rate tracing consistent with uteroplacental insufficiency led to immediate Cesarean birth of an anemic yet nonacidotic, nonhypoxic neonate, who did well following management of respiratory distress syndrome and partial exchange transfusion. Placental abruption was confirmed at delivery. Histopathology of the placenta confirmed the presence of localized chorangiomatosis ("wandering" chorangioma). The association of reverse diastolic flow of the fetal middle cerebral artery, placental chorangiomatosis and placental abruption has not been reported previously. We conclude that in the presence of prenatal sonographic findings of placental dysmorphology and or placental abruption, insonation of the fetal middle cerebral artery should be performed to assess the possibility of increased peak systolic velocity and possible reverse diastolic flow, both associated with fetal anemia and increased likelihood of an adverse perinatal outcome.

Current Perspectives of Prenatal Cell-free DNA Screening in Clinical Management of First-Trimester Septated Cystic Hygroma.

First-trimester septated cystic hygroma occurs in approximately 1 in 268 pregnancies and has long been associated with a markedly increased risk of fetal aneuploidy and, among euploid fetuses, an increased risk of structural anomalies primarily affecting the cardiac and skeletal systems. Invasive prenatal diagnosis - chorionic villus sampling and/or amniocentesis - encompasses the time-honored clinical tools for the next step in management following prenatal sonographic diagnosis of first-trimester septated cystic hygroma. Currently, prenatal cell-free DNA (cfDNA) screening for fetal aneuploidy with select microdeletions is gradually replacing the considerably less sensitive, and labor-intensive combined first-trimester screening. These new technologies have opened potential new venues in the clinical management of this ominous late first-trimester sonographic diagnosis. Advances in cfDNA technologies are now permitting detection of chromosomal copy number variants (CNV) larger than 7Mb across genome and select serious single-gene disorders (mainly impacting skeletal and neurological development), affecting quality of life and may benefit from medical and/or surgical management. This commentary will address the available non-invasive prenatal screening technologies, which clearly enhance immediate genetic analysis modalities applicable in the presence of the complex sonographic finding of first-trimester septated cystic hygroma.

Sonographic diagnosis of an interstitial pregnancy in an asymptomatic patient at 7 weeks' gestation.

An interstitial pregnancy is an ectopic pregnancy located within the proximal intramural segment of the Fallopian tube traversing the myometrium. This type of ectopic pregnancy is relatively rare, occurring in approximately 1%-3% of all ectopic pregnancies. Given the myometrial mantle surrounding the gestational sac, which is considerably thicker than in other tubal pregnancies, patients with interstitial pregnancies classically manifest symptoms later in gestation. Thus, there is an increased risk of life-threatening intraperitoneal hemorrhage upon rupture of the myometrium encompassing the pregnancy. We present an unusual case of early sonographic diagnosis of an interstitial pregnancy in an asymptomatic patient at 7 and 3/7 weeks' gestation, discuss predisposing factors, hallmarks of sonographic diagnosis, and review the literature regarding available clinical management modalities. With the increasing application of point of care ultrasound (POCUS) by emergency room physicians and other providers in outpatient facilities, our case emphasizes both the importance of correct sonographic identification of interstitial pregnancy and the clinical importance of uniform early first-trimester sonography, preferably no later than 7-8 weeks' gestation.

Mid-trimester dilated fetal bowel leading to diagnosis of interstitial duplication 46,XX,dup(8)(q21.13q21.2) associated with extensive neonatal jejuno-ileal atresia.

Small bowel atresia constitutes congenital obstruction of the lumen of the duodenum, jejunum or ileum, and is one of the most common causes of neonatal bowel obstruction with a reported incidence of between 1.3 and 2.8 per 10,1000 live births. Complete absence of the small bowel, or near total jejuno-ileal atresia (in the absence of malrotation or gastroschisis), are extremely rare. Mid-trimester prenatal sonographic finding of dilated fetal bowel led to the finding of interstitial 8q21.13q21.2 duplication. Following delivery at 32 weeks' gestation, at laparotomy almost complete small bowel atresia was noted. Anastomosis between the existing small bowel and colon was performed. At 7 months of age, the infant continued to receive total parenteral nutrition supplemented by gastrostomy and oral-spoon formula feeding, and weighed 7 kg (50th centile). This is the first report of the association interstitial 8q21.13q21.2 duplication, which includes OMIM genes (RALYL, LRRCC1, and E2F5) and extensive small bowel atresia.

Mid-trimester isolated bilateral rocker bottom feet leading to prenatal diagnosis of 7q11.23 microdeletion: Williams syndrome.

Prenatal sonographic depiction of congenital vertical talus (rocker bottom feet), describing a prominent calcaneus and rounded convex appearance of the ventral aspect of the foot, has been reported with fetal Trisomies 18, 13, 9 HOXD10 mutations and recently 2q13 microdeletion. We present a 24 year old in whom mid-trimester sonographic finding of isolated bilateral rocker bottom feet led to diagnosis of 7q11.23 microdeletion-Williams syndrome. This association has not been reported previously. This case emphasizes the critical assessment of detail microarray upon prenatal sonographic notation of abnormal structural fetal features.

Current Perspectives of Prenatal Sonography of Umbilical Cord Morphology.

The umbilical cord constitutes a continuation of the fetal cardiovascular system anatomically bridging between the placenta and the fetus. This structure, critical in human development, enables mobility of the developing fetus within the gestational sac in contrast to the placenta, which is anchored to the uterine wall. The umbilical cord is protected by unique, robust anatomical features, which include: length of the umbilical cord, Wharton's jelly, two umbilical arteries, coiling, and suspension in amniotic fluid. These features all contribute to protect and buffer this essential structure from potential detrimental twisting, shearing, torsion, and compression forces throughout gestation, and specifically during labor and delivery. The arterial components of the umbilical cord are further protected by the presence of Hyrtl's anastomosis between the two respective umbilical arteries. Abnormalities of the umbilical cord are uncommon yet include excessively long or short cords, hyper or hypocoiling, cysts, single umbilical artery, supernumerary vessels, rarely an absent umbilical cord, stricture, furcate and velamentous insertions (including vasa previa), umbilical vein and arterial thrombosis, umbilical artery aneurysm, hematomas, and tumors (including hemangioma angiomyxoma and teratoma). This commentary will address current perspectives of prenatal sonography of the umbilical cord, including structural anomalies and the potential impact of future imaging technologies.

Mid-trimester absent nasal bone and transient unilateral hydronephrosis associated with 16p13.3 microduplication.

Characteristic phenotypic features of 16p13.3 microduplication include impaired mental development, arthrogryposis-like musculoskeletal anomalies (club-feet, congenital hip dislocation, and camptodactyly of fingers and toes), facial dysmorphology, and at times congenital cardiac disease. Most of the described affected individuals have microduplications involving the CREBBP gene. Findings indicate this gene to be dosage-sensitive and likely involved in the phenotypes of 16p13.3 microduplication syndrome. We describe the incidental finding of 16p13.3 microduplication in a fetus with mid-trimester sonographic examination showing absent nasal bone and transient unilateral hydronephrosis.

Current Perspectives of Prenatal Sonographic Diagnosis and Clinical Management Challenges of Complex Umbilical Cord Entanglement.

Diagnosis of potential umbilical cord compromise, namely, true knots of the umbilical cord and nuchal cords has been enabled with increasing accuracy with current enhanced prenatal sonography. Often an incidental finding at delivery, the incidence of true knots of the umbilical cord has been estimated at between 0.04% and 3% of deliveries. This condition has been reported to account for a 4 to 10-fold increase of stillbirth and perinatal morbidity of 11% of cases. Nuchal cords, commonly observed at the delivery of uncompromised, non-hypoxic non-acidotic newborns occur more frequently with single nuchal cords noted in between 20% and 35% of all deliveries at term. Multiple nuchal cords are considerably less frequent, with decreasing frequencies inverse to the number of nuchal cord loops. While clearly single (and likely double) nuchal cords are almost uniformly associated with favorable neonatal outcomes, emerging data suggest that cases of ≥3 loops of nuchal cords are more likely to be associated with an increased risk of adverse perinatal outcome (either stillbirth or compromised neonatal condition at delivery). We define cases of a true knot of the umbilical cord, cases of ≥3 loops of nuchal cords, any combination of a true knot and nuchal cord, or any umbilical cord entanglement (nuchal or true knot) in the presence of a single umbilical artery, in singleton gestations as complex umbilical cord entanglement. Two concurrent developments, the increase in accuracy of prenatal sonographic diagnosis of complex umbilical cord entanglement and recent data confirming fatal compromise of the umbilical circulation in approximately 20% of cases of stillbirth, suggest that establishing governing body guidelines for reporting of potential umbilical cord compromise, and recommendation of consideration for early-term delivery of select cases, may be warranted. This commentary will address current perspectives of prenatal diagnosis and clinical management challenges of complex umbilical cord entanglement.

Incidental sonographic finding of a concealed placental abruption leading to delivery at 37 weeks' gestation.

Placental abruption occurs clinically in approximately 1% of births although placental pathology assessment suggests a higher incidence. Ultrasound rarely plays a role in the diagnosis or clinical management of patients with suspected placental abruption. A patient with an incidental sonographic finding of a large concealed abruption at 36 weeks' gestation, led to induction of labor. This case and the established association of increased stillbirth with placental abruption among patients of advanced maternal age, suggest that at term, following sonographic findings of abruption, consideration should be given to elective delivery of these patients even in the absence of clinical symptomatology.

Current Perspectives of Prenatal Sonographic Diagnosis and Clinical Management Challenges of Nuchal Cord(s).

Umbilical cord accidents preceding labor are uncommon. In contrast, nuchal cords are a very common finding at delivery, with reported incidences of a single nuchal cord of approximately between 20% and 35% of all singleton deliveries at term. Multiple loops occur less frequently, with reported incidence rates inverse to the number of nuchal cords involved. Rare cases of up to 10 loops of nuchal cord have been reported. While true knots of the umbilical cord have been associated with a 4-10-fold increased risk of stillbirth, nuchal cord(s) are most often noted at delivery of non-hypoxic non-acidotic newborns, without any evidence of subsequent adverse neonatal outcome. Prior to ultrasound, nuchal cords were suspected clinically following subtle (spontaneous or evoked) electronic fetal heart rate changes. Prenatal sonographic diagnosis, initially limited to real-time gray-scale ultrasound, currently entails additional sonographic modalities, including color Doppler, power Doppler, and three-dimensional sonography, which have enabled increasingly more accurate prenatal sonographic diagnoses of nuchal cord(s). In contrast to true knots of the umbilical cord (which are often missed at sonography, reflecting the inability to visualize the entire umbilical cord, and hence are often incidental findings at delivery), nuchal cord(s), reflecting their well-defined and sonographically accessible anatomical location (the fetal neck), lend themselves with relative ease to prenatal sonographic diagnosis, with increasingly high sensitivity and specificity rates. While current literature supports that single (and possibly double) nuchal cords are not associated with increased adverse perinatal outcome, emerging literature suggests that cases of ≥3 loops of nuchal cords or in the presence of a coexisting true knot of the umbilicus may be associated with an increased risk of stillbirth or compromised neonatal status at delivery. This commentary will address current perspectives of prenatal sonographic diagnosis and clinical management challenges associated with nuchal cord(s) in singleton pregnancies.

Prenatal sonography of extracorporeal ductus venosus in association with large fetal gastroschisis.

Liver herniation commonly associated with omphalocele occurs in only approximately 2.3% to 16% of fetuses with gastroschisis. Liver herniation in such cases is associated with considerably decreased survival rates (43% vs 97% with or without liver herniation, respectively). Rarely, abnormally positioned fetal hepatic vasculature has been reported mainly in association with congenital diaphragmatic hernia. In these rare cases, intrathoracic depiction of hepatic venous vasculature has assisted in confirming intrathoracic displacement of the fetal liver. We present a case of a large gastroschisis with complete herniation of the fetal liver in which prenatal sonography depicted an extracorporeal ductus venosus.

Mid-trimester fetal facial dysmorphology associated with 2p25.3 microdeletion.

We describe unusual mid-trimester sonography of subtle fetal facial dysmorphic features including; flattened nasofrontal angle with an almost vertically positioned nasal bone, acute nasolabial angle, and convexity of the maxillary areas in a fetus with otherwise normal anatomy. Microarray identified a 64.5 KB interstitial deletion of 2q25.3, which includes one exon of MYT1L. Mutations and deletions in MTY1L have been associated with autosomal dominant intellectual disability, autistic features, and obesity. Association of these features and 2p25.3 microdeletion has not been reported previously. This case emphasizes the importance of detailed microarray analysis following the sonographic recognition of subtle fetal dysmorphic features.

Current Perspectives of Prenatal Sonographic Diagnosis and Clinical Management Challenges of True Knot of the Umbilical Cord.

Umbilical cord accidents preceding labor are rare. Single and multiple nuchal cords, and true knot(s) of the umbilical cord, are often incidental findings noted at delivery of non-hypoxic non-acidotic newborns without any evidence of subsequent adverse neonatal outcome. In contrast to single nuchal cords, true knots of the umbilical cord, which occur in between 0.04% and 3% of all deliveries, have been associated with a reported 4 to 10 fold increased risk of stillbirth. First reported with real-time ultrasound, current widespread application of color Doppler, power Doppler and three-dimension sonography, has enabled increasingly more accurate prenatal sonographic diagnoses of true knot(s) of the umbilical cord. Reflecting the inability to visualize the entire umbilical cord at prenatal ultrasound assessment, despite detailed second and third-trimester scanning, many occurrences of incidental true knot of the umbilical cord remain undetected and are noted only at delivery. Although prenatal sonographic diagnostic accuracy is increasing, false positive sonographic diagnosis of true knot of the umbilical cord cannot be ruled out with certainty, and must continue to be considered clinically. Notwithstanding the inability to diagnose all true knots, currently there is a clear absence of clinical management guidelines by governing bodies regarding patients in whom prenatal sonographic diagnosis of true knot(s) of the umbilical cord is / are suspected. As a result, in many prenatal ultrasound units, suspected sonographic findings suggestive of or consistent with true knot of the umbilical cord are often disregarded, not documented, and patients are not uniformly informed of this potentially life-threatening condition, which carries an associated considerable risk of stillbirth. This commentary will address current perspectives of prenatal sonographic diagnostic and management challenges associated with true knot(s) of the umbilical cord in singleton pregnancies.