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

Outcomes of pregnancies diagnosed with circumvallate placenta, and use of uterine artery pulsatility index and maternal serum alpha-fetoprotein for prediction of adverse outcomes

OBJECTIVES

To evaluate the outcomes, and predictive value of uterine artery pulsatility index (UtA-PI) and second-trimester maternal serum alpha-fetoprotein (MSAFP) for adverse obstetric outcomes in cases with morphologically confirmed circumvallate placenta by comparison with normal pregnancies.

STUDY DESIGN

This prospective study was conducted in a tertiary referral hospital between January 2017 and December 2019. During the study period, 77 patients with a circumvallate placenta and 77 patients without any placental or feto-maternal diseases or abnormalities were evaluated. The final diagnosis was made based on macroscopic examination of the placenta soon after birth. Demographic characteristics, MSAFP, obstetric complications, haemoglobin after delivery, gestational week of birth, fetal sex, 1- and 5-min Apgar scores, postnatal complications and type of delivery were retrieved from hospital records. Bilateral mean transabdominal UtA-PI and MSAFP were evaluated for the prediction of adverse outcomes. SPSS Version 21.0 for Windows was used for statistical analysis, and receiver operating characteristic (ROC) curves were used for the prediction model of adverse outcomes.

RESULTS

Smoking rate, MSAFP, preterm birth and intrauterine growth restriction (IUGR) were higher in the patients with a circumvallate placenta (p = 0.005, 0.00, 0.025 and 0.027, respectively). The cut-off value of MSAFP was 1.41 (0.60-3.32) and the cut-off value of UtA-PI was 1.2 using the ROC curves, and had sensitivity of 73.7 % and specificity of 71.9 %, and sensitivity of 73.7 % and specificity of 76.3 %, respectively (p < 0.05).

CONCLUSIONS

Circumvallate placenta was associated with a higher rate of IUGR, preterm birth and bleeding at the time of delivery. In patients with a circumvallate placenta, UtA-PI and MSAFP may be valuable as predictors of IUGR.

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.

Placental Imaging: Normal Appearance with Review of Pathologic Findings

The placenta plays a crucial role throughout pregnancy, and its importance may be overlooked during routine antenatal imaging evaluation. Detailed systematic assessment of the placenta at ultrasonography (US), the standard imaging examination during pregnancy, is important. Familiarity with the normal and abnormal imaging appearance of the placenta along with the multimodality and methodical approach for evaluation of its related abnormalities is necessary, so that radiologists can alert clinicians regarding appropriate prompt management decisions. This will potentially decrease fetal and maternal morbidity and mortality. This article reviews early placental formation and the expected imaging appearance of the placenta during pregnancy, as well as variations in its morphology. It also discusses various placental diseases and their potential clinical consequences. Placental pathologic conditions include abnormalities of placental size, cord insertion, placental and cord location, and placental adherence. Other conditions such as bleeding in and around the placenta, as well as trophoblastic and nontrophoblastic tumors of the placenta, are also discussed. US with Doppler imaging is the initial imaging modality of choice for placental evaluation. Magnetic resonance (MR) imaging is reserved for equivocal cases or when additional information is needed. Computed tomography (CT) has a limited role in evaluation of placental abnormalities because of the ionizing radiation exposure and the relatively limited assessment of the placenta; however, CT can provide important information in specific circumstances, particularly evaluation of trauma and staging of choriocarcinoma. This article also addresses recent techniques and updates in placental imaging, including elastography, diffusion-weighted MR imaging, and blood oxygen level-dependent (BOLD) MR imaging. These advanced imaging techniques may provide additional information in evaluation of abnormal placental adherence and new insights into placental pathophysiology in selected patients. Online supplemental material is available for this article. ^©RSNA, 2017.

Sonography of placental abnormalities: a pictorial review

Often overlooked during routine ultrasound evaluation of a normal pregnancy, the placenta forms the biologic interface between the mother and fetus and is critical to fetal growth and development. Malformations in development, positioning, and vascularity can have profound implications for both maternal and fetal well-being. As such, a judicious inspection of the placenta is warranted as an integral part of every screening or emergent prenatal ultrasound. Herein, we present a pictorial review of a variety of placental pathologic conditions including abnormalities in positioning, adherence, vascularity, and hemorrhage as well as potential peri-placental masses and gestational trophoblastic disease, all of which are readily encountered in a busy emergency radiology practice.