The amniotic sheet: a truly benign condition?

A Case Report of Asherman's Syndrome With Abnormal Placenta Implantation (Intrauterine Adhesion)

We report the case of a 28-year-old patient with a partial placental insertion on an intrauterine adhesion diagnosed at 20 weeks' gestation. The increasing incidence of intrauterine adhesions during the last decade has been attributed to the rising number of uterine surgeries in the fertile population and better imaging studies facilitating diagnosis. Although uterine adhesions during pregnancy are generally considered benign, the existing evidence is conflicting. The obstetric risks in these patients are unclear, but higher numbers of placental abruption, preterm premature rupture of membranes (PPROM), and cord prolapse have been reported. Thus, a prenatal diagnosis should prompt close feto-maternal observation. Surgical resection should be offered to patients with adhesions found prior to pregnancy.

Prenatal ultrasonographic findings of adhesion-membrane complex and its relation with obstetric history

Background: Intrauterine adhesions are usually detected incidentally during routine obstetric ultrasound and remain one of the reasons for concern for both clinicians and patients.Objective: Our objective was to document ultrasonographic findings of intrauterine adhesions detected in obstetric ultrasound and to investigate their correlation with obstetric history.Study Design: Detailed scans were performed in 685 singleton pregnancies at 16-24 weeks' gestation. Intrauterine adhesion was referred to as "adhesion-membrane complex'' (AMC). Patients were divided into three groups: Group I consisted of patients with ≥1 therapeutic D&C associated with pregnancy but with neither vaginal delivery nor Cesarean section (CS). Group II consisted of patients with ≥1 CS but with neither vaginal delivery nor therapeutic D&C associated with pregnancy. Group III consisted of patients who were in their first pregnancy. Ultrasonographic properties of AMC and relationship between AMCs and obstetric history were investigated.Results: The incidence of AMC in Group I (n = 108), Group II (n = 189), and Group III (n = 388) was 11.1% (n = 12), 1.05% (n = 2) and 1.03% (n = 4), respectively. Positive history of D&C is associated with significantly increased risk of AMC (risk ratio:10.778; 95% confidence interval: 3.55-32.75). Also, previous history of CS is not associated with significantly increased risk of AMC (risk ratio: 1.026; 95% confidence interval: 0.19-5.55). The AMCs were located in the upper half in 7 (38,9%) and in the lower half of the uterus in 11 (61.1%) patients. The midpoint thickness of the AMC was between 0.75 and 5.10 mm (mean: 2.65 mm; SD ± 1.2). The width of the AMC was between 2 and 52 mm (mean: 20.98; SD ± 15.3), the heights of the AMCs were 5-60 mm (mean: 33.27 mm; SD ±17.0). In ten of the AMC positive patients (55.6%) a thick and bulbous free end and in eleven of them (61.1%) a "Y image" was detected. The mean gestational age at birth was 37.4 (SD ± 3.3) weeks in 18 patients with AMC. There were no intrauterine fetal or perinatal deaths. None of the neonates had congenital abnormalities.Conclusions: Intrauterine adhesions detected in obstetric ultrasonography were redefined and renamed in a more comprehensible manner. Our results pointed out that while the positive history of D&C is associated with significantly increased risk of AMC, previous history of CS is not associated with significantly increased risk of AMC.

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.

HDlive imaging of vertical, bridging uterine synechia during pregnancy

We present a case of vertical, bridging uterine synechia in the central part of the uterine cavity diagnosed by conventional two-dimensional (2D) sonography and HDlive at 29 weeks and 5 days of gestation. 2D sonography showed a uterine synechia located vertically in the central part of the uterine cavity, dividing the lower uterine cavity into two parts. HDlive clearly revealed triangular, vertical, and bridging uterine synechia with foot protrusion and umbilical cord prolapse in the lower uterine cavity. The low, liquor-filled amniotic cavity was divided by a thin membrane. MRI confirmed the vertical structure dividing the uterus with umbilical cord prolapse. Emergency cesarean section was performed at 37 weeks and 1 day of gestation because of onset of labor, and a female infant weighing 2,380 g was delivered with an umbilical artery pH of 7.25, and Apgar score of 6/9 at 1 and 5 min, respectively. The vertical, bridging synechia in the central part of uterine cavity was confirmed during the operation.

Obstetric morbidity associated with amniotic sheets

OBJECTIVE

The objective of this study was to determine whether amniotic sheets are associated with an increase in obstetric and neonatal morbidity.

METHODS

Using a cohort study design, we identified all women with amniotic sheets, detected by a second-trimester ultrasound examination at a university hospital over a 6-year period. All women who received an ultrasound examination during that time, without a diagnosis of amniotic sheets, were also identified, and two women from among this group were randomly selected as controls for each case. Maternal and neonatal data were abstracted from the medical records, and maternal and neonatal morbidity were compared between the two groups.

RESULTS

One hundred and twenty-two women with pregnancies with a diagnosis of amniotic sheets were identified and compared to 244 women with pregnancies without a diagnosis of amniotic sheets. Composite obstetric morbidity was higher in women with amniotic sheets: 21.3% vs. 8.2% (relative risk (RR) 2.6; 95% CI, 1.5-4.5). Additionally, in women with amniotic sheets, neonates were more likely to be born with a birth weight of < 2500 g (RR 3.3; 95% CI, 1.8-6.4) and were more likely to be admitted to the neonatal intensive care unit (RR 2.3; 95% CI, 1.3-4.3). There were no perinatal deaths observed in either group.

CONCLUSION

Amniotic sheets are associated with an increase in adverse obstetric outcomes.

Placental shelf - a common, typically transient and benign finding on early second-trimester sonography

OBJECTIVE

Placental shelves are believed to represent circumvallate placentae. It is thought that circumvallate placenta may be associated with adverse perinatal outcome when present at delivery. The objective of this study was to determine the prevalence, persistence and significance of placental shelves detected in the early second trimester.

METHODS

In 152 consecutive anomaly scans performed between 13 and 16 weeks of gestation, special attention was directed to placental structure and the presence of a placental shelf. When present, a mid-gestation scan was performed to verify if the finding persisted. If so, a third-trimester scan was performed. Delivery charts were reviewed for all cases initially diagnosed with a placental shelf, recording any placenta-related complications.

RESULTS

In 17 of 152 (11.2%) early second-trimester scans a placental shelf was detected. In three of these 17 cases the shelf persisted to the 20-22-week scan. In the two cases that presented for the third-trimester scan the shelf was no longer present. In all 17 cases the perinatal outcome was good.

CONCLUSIONS

In our study group early second-trimester placental shelves rarely persisted to mid-gestation and never to the third trimester. There were no placenta-related perinatal problems. Early second-trimester placental shelf appears to be a common, benign and transient sonographic finding.