Prenatal imaging of amniotic band sequence: utility and role of fetal MRI as an adjunct to prenatal US

Diagnosis and Management of 2 Cases of Spontaneous Septostomy: Monochorionic/Dichorionic Hybrid Twin Gestation and Dichorionic Triamniotic Triplet Gestation

INTRODUCTION

Spontaneous septostomy is a rare complication of multiple gestations. Related complications include cord entanglement and preterm delivery. Limited data exist to guide the management of these high-risk patients. The majority of spontaneous septostomy cases have been reported in monochorionic diamniotic twins. We present 2 cases of spontaneous septostomy occurring in a monochorionic/dichorionic hybrid twin gestation (chorionicity transitions from dichorionicity to monochorionicity within the placenta) and in a dichorionic triamniotic triplet gestation.

CASE PRESENTATION

Case 1 was a monochorionic/dichorionic hybrid twin gestation with a septostomy complicated by fetal parts of one twin protruding into the co-twin's sac as well as symptomatic polyhydramnios. Fetal magnetic resonance imaging confirmed the septostomy. Case 2 was a dichorionic triamniotic triplet gestation with septostomy and cord entanglement. Both patients were managed akin to a pseudo-monoamniotic gestation with serial ultrasound surveillance and eventual inpatient admission for heightened fetal monitoring. Case 1 underwent elective scheduled cesarean delivery at 33 weeks, and case 2 underwent emergent cesarean delivery for fetal heart rate decelerations at 28 weeks.

CONCLUSION

With a high degree of clinical suspicion, spontaneous septostomy can be diagnosed in uncommon settings such as hybrid twin gestations and higher order multiples. Management of such patients is individualized and may include a combination of heightened outpatient and inpatient surveillance.

Amniotic band syndrome in a monochorionic diamniotic twin pregnancy after rupture of the dividing membrane in the early second trimester: A case report

BACKGROUND

Amniotic band syndrome is a rare phenomenon, but it can result in serious complications. We report herein our experience of amniotic band syndrome in a monochorionic diamniotic twin pregnancy where rupture of the dividing membrane occurred early in the second trimester.

CASE PRESENTATION

A 29-year-old nulliparous woman was referred to us for management of her monochorionic diamniotic twin pregnancy at 10 weeks of gestation. When we were unable to identify a dividing membrane at 15 weeks of gestation using two-dimensional ultrasonography, we used three-dimensional ultrasonography to confirm its absence. Both modalities showed that the left arm of baby B was swollen and attached to a membranous structure originating from the placenta at 18 weeks of gestation. Tangled umbilical cords were noted on magnetic resonance imaging at 18 weeks of gestation. Emergency cesarean delivery was performed at 30 weeks of gestation because of the nonreassuring fetal status of baby A. The left arm of baby B had a constrictive ring with a skin defect. Both neonates had an uncomplicated postnatal course and were discharged around 2 months after delivery.

CONCLUSIONS

Attention should be paid to the potential for amniotic band syndrome if rupture of the dividing membrane between twins is noted during early gestation.

Magnetic resonance imaging of the fetal musculoskeletal system

Diagnosing musculoskeletal pathology requires understanding of the normal embryological development. Intrinsic errors of skeletal development are individually rare but are of paramount clinical importance because anomalies can greatly impact patients' lives. An accurate assessment of the fetal musculoskeletal system must be performed to provide optimal genetic counseling as well as to drive therapeutic management. This manuscript reviews the embryology of skeletal development and the appearance of the maturing musculoskeletal system on fetal MRI. In addition, it presents a comprehensive review of musculoskeletal fetal pathology along with postnatal imaging.

Osteomyelitis in limb amputated by amniotic band sequence

A preterm (30⁺² week) neonate with below-knee amputation (right lower limb), constriction rings and syndactyly, subsequent to amniotic band sequence, developed pus discharge from the right tibial stump. The neonate did not have clinical features of systemic sepsis. Blood culture was sterile. The pus culture, however, grew methicillin-resistant coagulase-negative Staphylococcus and bone scan was suggestive of osteomyelitis of right proximal tibial stump. Osteomyelitis was likely caused by the contiguous spread of infection from the exposed stump. Neonate was treated with intravenous antibiotics for 4 weeks and discharged on oral feeds.

Intrauterine Linear Echogenicities in the Gravid Uterus: What Radiologists Should Know

Intrauterine linear echogenicity (ILE) is a common ultrasonographic finding in the gravid uterus and has variable causes and variable maternal and fetal outcomes. Correctly categorizing ILE during pregnancy is crucial for guiding surveillance and advanced imaging strategies. Common causes of ILE include membranes in multiple gestations, uterine synechiae with amniotic sheets, and uterine duplication anomalies. Less common causes include circumvallate placenta, chorioamniotic separation, and hemorrhage between membranes. Amniotic band syndrome is a rare but important diagnosis to consider, as it causes severe fetal defects. Imaging findings enable body stalk anomaly, a lethal defect, to be distinguished from amniotic bands, which although destructive are not necessarily lethal. This review describes the key imaging findings used to differentiate the various types of ILE in pregnancy, thus enabling accurate diagnosis and appropriate patient counseling. Online supplemental material is available for this article. ^©RSNA, 2018.

Amniotic Band Syndrome, Perinatal Hospice, and Palliative Care versus Active Management

Introduction. Amniotic band syndrome and sequence are a relatively rare condition in which congenital anomalies occur as a result of the adherence and entrapment of fetal parts with coarse fibrous bands of the amniotic membrane. A large percentage of reported cases have an atypical gestational history. The frequency of this obstetric complication is not affected by fetal gender, genetic abnormality, or prenatal infection. Case. A 21-year-old, G1P0 female parturient at 18 weeks and 5 days with a single intrauterine gestation during a routine ultrasound evaluation was noted to have amniotic band sequence. The pregnancy was subsequently complicated by preterm premature rupture of membranes with oligohydramnios, resulting in a surviving neonate scheduled for rehabilitative treatment. Conclusion. Amniotic band syndrome is an uncommon congenital anomaly resulting in multiple disfiguring and disabling manifestations. Several theories are proposed with most involving early rupture of the amnion and entanglement of fetal parts by amniotic bands. This syndrome can be manifested by development of multiple malformations, with the majority of the defects being limb abnormalities of a disorganized nature, as in the case we present. In the absence of a clear etiology of consequential congenital abnormalities, obstetric management guidelines should use shared decision models to focus on the quality of life for the offspring.

Extrafetal Findings on Fetal Magnetic Resonance Imaging: A Pictorial Essay

Although US is the mainstay of fetal imaging, magnetic resonance imaging (MRI) has become an invaluable adjunct in recent years. MRI offers superb soft tissue contrast that allows for detailed evaluation of fetal organs, particularly the brain, which enhances understanding of disease severity. MRI can yield results that are similar to or even better than those of US, particularly in cases of marked oligohydramnios, maternal obesity, or adverse fetal positioning. Incidentally detected extrafetal MRI findings are not uncommon and may affect clinical care. Physicians interpreting fetal MRI studies should be aware of findings occurring outside the fetus, including those structures important for the pregnancy. A systematic approach is necessary in the reading of such studies. This helps to ensure that important findings are not missed, appropriate clinical management is implemented, and unnecessary follow-up examinations are avoided. In this pictorial essay, the most common extrafetal abnormalities are described and illustrated.

Amniotic band syndrome with sacral agenesis and umbilical cord entrapment: A case report emphasizing the value of evaluation of umbilical cord

Amniotic band syndrome is a rare congenital disorder caused by entrapment of fetal parts by fibrous amniotic bands in utero. The congenital anomalies seen in this syndrome vary widely and defects may be isolated or multiple and do not follow a specific pattern. Asymmetric distribution of defects is the hallmark of this syndrome. The diagnosis is difficult to make on ultrasound and relies on identification of amniotic bands. We report a case of amniotic band syndrome with sacral agenesis diagnosed on routine antenatal ultrasound scan in the second offspring of a recently diagnosed diabetic mother. The associated features were entrapment of umbilical cord, caudal adhesions and lower limb anomalies. Medical termination of pregnancy was done and all the fetal anomalies as well as umbilical cord abnormalities were confirmed. The importance of meticulous scanning to evaluate for amniotic bands and the umbilical cord in addition to the fetal structures is emphasized.

Preventing misdiagnosis in amniotic band sequence: a case report

Amniotic band sequence (ABS) is an uncommon and heterogeneous congenital disorder caused by entrapment of fetal parts by fibrous amniotic bands, causing distinctive structural abnormalities involving limbs, trunk, and craniofacial regions. The incidence ranges between 1/1200 and 1/15,000 live births, but is higher in stillbirths and previable fetuses. The intrinsic theory attributes the constriction band syndrome as an inherent development defect of embryogenesis while the extrinsic theory proposes that an early amnion rupture is responsible for the adherent bands. It is also suggested that amputations and constriction rings might be due to vascular disturbances. Anomalies resulting from amniotic bands are quite variable and sometimes may simulate chromosomal abnormalities. The authors report a case of a 36-week-gestation male neonate who lived for 29 hours after a vaginal delivery with an Apgar score of 8/9/9. The mother was primipara, and the prenatal was uneventful except for two episodes of urinary tract infections. The newborn examination depicted multiple anomalies characterized by exencephaly, bilateral labial cleft with distorted nostrils and palate cleft. There was also facial skin tag band, exophthalmos with hypoplasia of the eyelids. The limbs showed distal amputation of the fingers in both hands and feet, oligodactyly associated with syndactyly in the left foot, ring constriction in the right leg, the presence of right hyperextension, and clubfoot. The upper limbs showed length discrepancies. Karyotype analysis was normal at 46 XY. The authors conclude that the recognition of the malformations secondary to ABS is important in genetic counseling to prevent misdiagnosis between chromosomal and secondary disruption disorders.