Placental abruption and hemorrhage-review of imaging appearance

Preterm placental abruption and its association with adverse maternal and neonatal outcomes: a retrospective study

BACKGROUND

Placental abruption (PA), a severe obstetric complication, defined as the partial or complete detachment of a normally situated placenta from the uterine wall before birth, after 20 weeks of gestation, is associated with significant maternal and neonatal morbidity and mortality. Despite its clinical importance, the pathogenesis of PA remains unclear, and there is limited research specifically comparing outcomes in term and preterm pregnancies with PA. This study aimed to evaluate maternal and neonatal outcomes in pregnancies complicated by PA on basis of the timing of PA onset, with a focus on differences between term and preterm deliveries.

METHODS

This retrospective study included a total of 757 singleton pregnant women with confirmed PA from a tertiary obstetrics hospital care center between June 2020 to March 2024, who were classified into the preterm group (n = 300) and the full-term group (n = 457) based on their gestational age of PA onset. The baseline characteristics, maternal and newborn outcomes were collected from electronic health records in hospital information system, and further analyzed between two groups. The adjusted odds ratios (aORs) for the risk of adverse pregnancy outcomes on basis of term or preterm delivery in women with PA were analyzed by using multivariate logistic regression models.

RESULTS

Women with preterm delivery had about 3 times greater risk for uterus-placenta apoplexy (aOR: 2.93, 95% CI 1.33-6.47, P = 0.01), 3 times greater risk for fetal growth restriction (aOR: 3.47, 95% CI 1.45-8.30, P = 0.01), 3 times greater risk for adult intensive care unit (ICU, aOR: 3.28, 95% CI 1.27-8.46, P = 0.01), and less chances to use oxytocin (aOR: 0.21, 95% CI 0.13-0.32, P < 0.01). Premature newborns had less chances to use forceps (aOR: 0.09, 95% CI 0.01-0.76, P = 0.02), but about 10 times greater risk for stillbirth (aOR: 9.38, 95% CI 1.10 - 79.68, P < 0.01).

CONCLUSIONS

Preterm pregnancies with PA are associated with higher risks of severe maternal complications and adverse neonatal outcomes, underscoring the need for enhanced clinical surveillance and timely intervention. Future research should focus on elucidating underlying mechanisms and developing effective prevention strategies, while long-term follow-up is essential to assess the health outcomes of affected infants.

CLINICAL TRIAL NUMBER

Not applicable.

Placental Abruption: Pathophysiology, Diagnosis, and Management

Placental abruption is a complete or partial separation of the placenta from the uterine decidua. Clinical manifestations include vaginal bleeding, abdominal pain, uterine contractions, and abnormalities in the fetal heart rate tracing. Placental abruption occurs in 0.4% to 1.0% of all pregnancies. However, the pathophysiology remains incompletely understood. We present a review of the pathophysiology, diagnosis, and management of placental abruption, exploring overlapping processes which contribute to premature placental separation. Classic findings and limitations of ultrasound in evaluating placental abruption are explained. Finally, we discuss the management of placental abruption based on gestational age, fetal status, and maternal hemodynamic stability.

Diagnostic efficacy of virtual organ computer-assisted analysis in measuring the volume ratio of subchorionic hematoma with serum progesterone

BACKGROUND

Subchorionic hematoma (SCH) is a common complication in early pregnancy characterized by the accumulation of blood between the uterine wall and the chorionic membrane. SCH can lead to adverse pregnancy outcomes such as miscarriage, preterm birth, and other complications. Early detection and accurate assessment of SCH are crucial for appropriate management and improved pregnancy outcomes.

AIM

To evaluate the diagnostic efficacy of virtual organ computer-assisted analysis (VOCAL) in measuring the volume ratio of SCH to gestational sac (GS) combined with serum progesterone on early pregnancy outcomes in patients with SCH.

METHODS

A total of 153 patients with SCH in their first-trimester pregnancies between 6 and 11 wk were enrolled. All patients were followed up until a gestational age of 20 wk. The parameters of transvaginal two-dimensional ultrasound, including the circumference of SCH (Cs), surface area of SCH (Ss), circumference of GS (Cg), and surface area of GS (Sg), and the parameters of VOCAL with transvaginal three-dimensional ultrasound, including the three-dimensional volume of SCH (3DVs) and GS (3DVg), were recorded. The size of the SCH and its ratio to the GS size (Cs/Cg, Ss/Sg, 3DVs/3DVg) were recorded and compared.

RESULTS

Compared with those in the normal pregnancy group, the adverse pregnancy group had higher Cs/Cg, Ss/Sg, and 3DVs/3DVg ratios (P < 0.05). When 3DVs/3DVg was 0.220, the highest predictive performance predicted adverse pregnancy outcomes, resulting in an AUC of 0.767, and the sensitivity, specificity were 70.2%, 75% respectively. VOCAL measuring 3DVs/3DVg combined with serum progesterone gave a diagnostic AUC of 0.824 for early pregnancy outcome in SCH patients, with a high sensitivity of 82.1% and a specificity of 72.1%, which showed a significant difference between AUC.

CONCLUSION

VOCAL-measured 3DVs/3DVg effectively quantifies the severity of SCH, while combined serum progesterone better predicts adverse pregnancy outcomes.

Succenturiate Placental Lobe Abruption

Placental development is a complex process which sets the stage for normal fetal development. Any variation/disruption occurring during the initial stages of placental formation leads to placental malfunction causing increased maternal-fetal morbidity and mortality. The succenturiate lobe is a structural variation of the placenta that usually appears as a distinct lobe from the main placental mass. Succenturiate lobe is a rare placental anomaly, with high risk of fetal distress, hemorrhage, abruptio placentae and even fetal death because the vessels of this succenturiate lobe are vulnerable to both compression and laceration. Prenatal imaging diagnosis of this pathology improves the fetal prognosis through more careful surveillance and, in case of complications such as abruptio placentae, by shortening the time-to-decision making in favor of cesarean delivery. We present the case of a 27-year-old patient, without risk factors for placental abnormalities, diagnosed antenatally with succenturiate placenta, who presented at 34 weeks of pregnancy for abruptio placentae.

Correlation Between Maternal-Fetus Interface and Placenta-Mediated Complications

Pregnancy is a highly regulated biological phenomenon that involves the development of a semi-allogeneic fetus inside the uterus of the mother. The maternal-fetal interface is a critical junction where communication takes place between the fetal and maternal immune systems, which determine the outcome of the pregnancy. The interface is composed of the decidua and placenta. The main cells present at the maternal-fetal interface include invading trophoblasts, maternal immune cells, and decidual stromal cells. Although maternal tolerance is crucial for maintaining a successful pregnancy, the role of the placenta in pregnancy is also important. Dysregulation of the placenta leads to various placenta-mediated complications, such as preeclampsia, intrauterine growth restriction, and placental abruption. Although the exact mechanism involving these complications is unclear, research has elucidated various factors involved in these pregnancy disorders. This review aimed to provide a summary of the maternal-fetal interface and immune mechanisms involved in placenta-mediated complications.

Prediction of antenatal bleeding and preterm deliveries using placental magnetic resonance imaging in patients with placenta previa

PURPOSE

This study aimed to clarify associations between subacute hematoma on placental magnetic resonance imaging (MRI), antenatal bleeding, and preterm deliveries in patients with placenta previa (PP) without placenta accreta spectrum (PAS).

MATERIALS AND METHODS

This retrospective study investigated 78 consecutive patients with PP (median age, 34.5 years; interquartile range [IQR], 31-37 years) who underwent placental MRI in the third trimester. Patients with PAS detected intraoperatively or pathologically were excluded. Two radiologists evaluated the presence of subacute hematomas and their locations on placental MRI. We examined associations between presence of subacute hematoma and antenatal bleeding, emergency cesarean section (CS), hysterectomy, gestational age (GA) at delivery, birth weight, and amount of blood loss at CS. We also examined the association between perinatal outcome and subacute hematoma location: marginal, retro-placental, or intra-placental. Inter-observer agreement for the detection of subacute hematoma was calculated using kappa analysis.

RESULTS

Subacute hematomas were identified on MRI in 39 of the 78 patients (50.0%). Antenatal bleeding and emergency CS were more prevalent in patients with subacute hematoma on MRI (20 patients [51.3%] and 18 patients [46.2%], respectively) than in patients without (7 patients [17.9%], Fisher's exact test, p = 0.004 and 7 patients [17.9%], p = 0.014, respectively). GA at delivery was significantly lower in patients with subacute hematoma (median 36w3d, IQR 35w4d-37w1d) than in patients without (median 37w1d, IQR 36w4d-37w2d; Mann-Whitney test: p = 0.048). Marginal hematoma was significantly associated with antenatal bleeding and emergency CS. Inter-observer agreement for the presence of subacute hematoma was moderate (κ = 0.573).

CONCLUSION

Subacute hematoma on placental MRI was associated with antenatal bleeding, emergency CS and shorter GA at delivery in patients with PP. Marginal hematoma was also associated with antenatal bleeding and emergency CS. Placental MRI appears useful for predicting antenatal bleeding and preterm delivery in patients with PP.

Imaging of Antepartum and Postpartum Hemorrhage

Severe obstetric hemorrhage is a leading cause of maternal mortality and morbidity worldwide. Major hemorrhage in the antepartum period presents potential risks for both the mother and the fetus. Similarly, postpartum hemorrhage (PPH) accounts for up to a quarter of maternal deaths worldwide. Potential causes of severe antepartum hemorrhage that radiologists should be familiar with include placental abruption, placenta previa, placenta accreta spectrum disorders, and vasa previa. Common causes of PPH that the authors discuss include uterine atony, puerperal genital hematomas, uterine rupture and dehiscence, retained products of conception, and vascular anomalies. Bleeding complications unique to or most frequently encountered after cesarean delivery are also enumerated, including entities such as bladder flap hematomas, rectus sheath and subfascial hemorrhage, and infectious complications of endometritis and uterine dehiscence. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material. See the invited commentary by Javitt and Madrazo in this issue.

The impact of first-trimester subchorionic hematomas on pregnancy outcomes after euploid embryo transfer: a retrospective cohort study

BACKGROUND

The aim of the retrospective cohort study was to investigate the prognostic effect of subchorionic hematomas (SCH) in the first trimester on pregnancy outcomes after euploid embryo transfer.

METHODS

We retrospectively analyzed women achieving singleton pregnancy by PGT-A or PGT-SR from January 2017 to January 2022. Patients were enrolled in the study if they had a viable intrauterine pregnancy at ultrasound between 6 0/7 and 8 0/7 weeks of gestation. Pregnancy outcomes as well as the incidence of maternal complications were compared between patients with and without SCH. Logistic regression was used for adjusting for potential confounding factors.

RESULTS

A total of 1539 women were included, of which 298 with SCH and 1241 with non-SCH. The early miscarriage rate in SCH group was significantly higher than that in the non-SCH group (10.1% vs. 5.6%, adjusted odds ratio [aOR] 1.99, 95% confidence interval [CI] 1.25-3.16, P = 0.003). The live birth rate in SCH group was significantly lower than that in the non-SCH group. (85.6% vs. 91.2%, aOR 0.57, 95% CI 0.39-0.84, P = 0.005). In addition, SCH group had an increased risk of hypertensive disorder of pregnancy (HDP) (8.9% vs. 5.2%, P = 0.022), especially in hematoma with bleeding (19.3% vs. 6.0%, P = 0.002). The incidence of gestational diabetes mellitus (GDM), major congenital abnormalities rate, normal birth weight rate and low birth weight rate were similar between the two groups.

CONCLUSIONS

The presence of SCH in the first trimester was associated with worse pregnancy outcomes after euploid embryo transfer, including an increased risk of early miscarriage and hypertensive disorder of pregnancy, along with a reduced live birth rate.

Subchorionic hematoma: Research status and pathogenesis (Review)

Subchorionic hematoma (SCH) is a hematoma in which blood accumulates between the chorion and decidua basalis due to the separation of the chorion and decidua basalis. It is common in patients with threatened abortion in early pregnancy and is mainly detected by ultrasound. SCH mainly manifests as an hypoechoic or anechoic crescent-shaped fluid dark area on ultrasound images. Although there are numerous studies on SCH, its pathogenesis and etiology remain unclear, and its influence on pregnancy outcomes is also controversial; there are also no uniform clinical treatment guidelines. Current studies suggest that the occurrence of SCH may be related to several factors, such as abnormal coagulation function, autoimmune factors of pregnant women, assisted reproduction, drug use during pregnancy and reproductive tract infection; however, its exact etiology remains unclear. Some studies suggest that SCH is associated with adverse pregnancy outcomes such as miscarriage, preterm birth, preeclampsia and fetal growth restriction, although other studies have found that SCH does not increase the risk of adverse pregnancy outcomes. Therefore, the present review mainly discusses the pathogenesis, etiology and treatment of SCH in an aim to provide a reference for the clinical treatment of this condition in pregnant women.

Gynaecological Causes of Acute Pelvic Pain: Common and Not-So-Common Imaging Findings

In female patients, acute pelvic pain can be caused by gynaecological, gastrointestinal, and urinary tract pathologies. Due to the variety of diagnostic possibilities, the correct assessment of these patients may be challenging. The most frequent gynaecological causes of acute pelvic pain in non-pregnant women are pelvic inflammatory disease, ruptured ovarian cysts, ovarian torsion, and degeneration or torsion of uterine leiomyomas. On the other hand, spontaneous abortion, ectopic pregnancy, and placental disorders are the most frequent gynaecological entities to cause acute pelvic pain in pregnant patients. Ultrasound (US) is usually the first-line diagnostic technique because of its sensitivity across most common aetiologies and its lack of radiation exposure. Computed tomography (CT) may be performed if ultrasound findings are equivocal or if a gynaecologic disease is not initially suspected. Magnetic resonance imaging (MRI) is an extremely useful second-line technique for further characterisation after US or CT. This pictorial review aims to review the spectrum of gynaecological entities that may manifest as acute pelvic pain in the emergency department and to describe the imaging findings of these gynaecological conditions obtained with different imaging techniques.

Imaging of Acute Abdominopelvic Pain in Pregnancy and Puerperium-Part I: Obstetric (Non-Fetal) Complications

Acute abdominopelvic pain in pregnant and postpartum patients presents clinical and therapeutic challenges, often requiring quick and accurate imaging diagnosis. Ultrasound remains the primary imaging investigation. Magnetic resonance imaging (MRI) has been shown to be a powerful diagnostic tool in the setting of acute abdominal pain during pregnancy and puerperium. MRI overcomes some drawbacks of US, avoiding the ionizing radiation exposure of a computed tomography (CT) scan. Although CT is not usually appropriate in pregnant patients, it is crucial in the emergency evaluation of postpartum complications. The aim of this article is to provide radiologists with a thorough familiarity with the common and uncommon pregnancy and puerperium abdominal emergencies by illustrating their imaging appearances. The present first section will review and discuss the imaging findings for acute abdominopelvic pain of obstetric (non-fetal) etiology.

Fibrinogen for the prediction of severe maternal complications in placental abruption with fetal death after 24 weeks of gestation

OBJECTIVE

To assess the correlation between standard laboratory indicators at admission and severe maternal complications due to placental abruption (PA) with intrauterine fetal death (IUFD) after 24 weeks.

METHODS

Retrospective study in three French tertiary referral hospitals. Correlation of laboratory indicators at admission (platelet count, prothrombin, activated partial thromboplastin time, fibrinogen) and severe maternal complications (massive transfusion, multiple organ failure, hysterectomy, or maternal deaths) in patients with PA and IUFD.

RESULTS

Over 12 years, we identified 27/344 (7.8%) pregnant women presenting PA with IUFD. No patient had coagulopathy at admission. Fifteen individuals (55.5%) underwent delivery by cesarean section before or during labor. Fifteen individuals (55.5%) presented severe complications, and 17/27 (63%) lost more than 1 L of blood during delivery. Fibrinogen level was shown to be the laboratory indicator most correlated with severe complications (r = -0.52, P = 0.01). The receiver operating characteristic curve of fibrinogen less than 1.9 g/L in the prediction of severe complications (area under the curve = 0.80, 95% confidence interval [CI] 0.54-0.97) showed both a sensitivity and specificity of 83% (95% CI 54%-96%).

CONCLUSIONS

In cases of IUFD with PA, fibrinogen levels at admission had a prognostic value for the prediction of severe maternal complications.

Subchorionic Hemorrhage in the Second and Third Trimesters of Pregnancy: A Review

Importance

Subchorionic hemorrhage (SCH) in the second and third trimesters of pregnancy can be associated with maternal morbidity and fetal morbidity/mortality. Management of SCH in the second or third trimesters can be complicated, especially in the setting of a large SCH that requires hospitalization and blood transfusion.

Objective

The aim of this review is to describe SCH in second and third trimesters, risk factors, diagnosis, maternal and fetal outcomes, and management of this uncommon pregnancy complication.

Evidence Acquisition

A PubMed, Web of Science, and CINAHL search was undertaken with no limitations on the number of years searched.

Results

There were 123 abstracts and/or articles reviewed, with 48 articles being the basis of review. The only known risk factors for SCH are maternal factor deficiency and anticoagulation therapy. The diagnosis is usually made by ultrasound imaging. Subchorionic hemorrhage in second and third trimesters has been associated with several adverse fetal outcomes including preterm birth, preterm prelabor rupture of membranes, fetal growth restriction, fetal demise, and neonatal pulmonary morbidity. There is no proven treatment for SCH, although there are several investigational therapies reported.

Conclusions

Subchorionic hemorrhage can be complex and difficult to manage in the second and third trimesters. There are no recommendations or guidelines for management; however, serial growth ultrasounds, umbilical artery Doppler studies, and antenatal fetal testing should be considered particularly if the SCH is large or treatment requires a maternal blood transfusion.

Relevance

Subchorionic hemorrhage in the second and third trimester is associated with poor fetal outcomes and maternal morbidity, especially if the SCH is significant.

Ultrasonographic findings of placental abruption observed on superb microvascular imaging

OBJECTIVE

To demonstrate ultrasound pathological findings of placental abruption (PA) detected using a new Doppler method: superb microvascular imaging (SMI).

CASE REPORT

The patient was a pregnant woman with dark brown vaginal discharge at 32 + 4 weeks of gestation. Conventional ultrasound revealed an exophytic heterogeneous area measuring 3 cm, between the placenta and myometrium. SMI showed no minor blood flow inside the area. A diagnosis of marginal sub-chorionic hematoma was made. On the seventh day of hospitalization, SMI showed pulsation of blood flow in the inter-villous space and fetal blood flow in the villous trees. Due to an increase in the frequency of uterine contractions, an emergency cesarean section was performed. Histopathological examination showed hematomas beneath the decidual tissue, and the decidual layer was undamaged. The inter-villous space was preserved.

CONCLUSION

SMI can contribute to a more accurate PA diagnosis that may lead to timely administration of obstetric intervention.

Doppler evaluation of normal and abnormal placenta

Doppler techniques are needed for the evaluation of the intraplacental circulation and can be of great value in the diagnosis of placental anomalies. Highly sensitive Doppler techniques can differentiate between the maternal (spiral arteries) and fetal (intraplacental branches of the umbilical artery) components of the placental circulation and assist in the evaluation of the placental functional units. A reduced number of placental functional units can be associated with obstetric complications, such as fetal growth restriction. Doppler techniques can also provide information on decidual vessels and blood movement. Abnormal decidual circulation increases the risk of placenta accreta. Doppler evaluation of the placenta greatly contributes to the diagnosis and clinical management of placenta accreta, vasa previa, placental infarcts, placental infarction hematoma, maternal floor infarction, massive perivillous fibrin deposition and placental tumors. However, it has a limited role in the diagnosis and clinical management of placental abruption, placental hematomas, placental mesenchymal dysplasia and mapping of placental anastomoses in monochorionic twin pregnancies. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Maternal and neonatal outcomes of expectantly managed pregnancies with previable preterm premature rupture of membranes

PURPOSE

This study aimed to describe the maternal and fetal outcomes associated with expectant management following previable preterm premature rupture of membranes (PPROM) before 24 weeks of gestation. We also analyzed the risk estimates of potential confounders to clarify whether these variables are contributed to the risk of postnatal mortality among these neonates.

METHODS

This retrospective cohort study included all pregnant patients who experienced previable PPROM before 24 weeks of gestation at a tertiary maternal-fetal medicine center. We used the neonatal data from birth until discharge.

RESULTS

A total of 128 women were enrolled. The survival to discharge rate was 60.9%. The median latency period (80 vs. 20 days, respectively, p < 0.001) was significantly longer, the median gestational week at delivery (34 vs. 25 weeks, respectively, p < 0.001) and median birth weight (2100 vs. 710 g, p < 0.001) was significantly higher in the survivor group than the non-survivor group. Surviving neonates had significantly lower frequencies of anhydramnios at any time during the latency period than the non-survivor neonates (38.4% vs. 86.0%, respectively, p < 0.001).

CONCLUSION

This study demonstrated an opposite correlation between the duration of latency period and gestational age at PPROM with earlier membrane rupture in pregnancies having a longer latency period, which additionally clarifies the higher gestational age at delivery. The antepartum factors that increased the possibility of postnatal mortality within our study included the gestational week at delivery, duration of the latency period, anhydramnios at any time during the latency period, and birth weight.

The evaluation of the antepartum and intrapartum risk factors in predicting the risk of birth asphyxia

PURPOSE

This study aimed to determine the related antepartum and intrapartum factors of birth asphyxia among neonates born in a tertiary referral hospital.

METHODS

A total of 45 singleton pregnant women who delivered live births with a gestational age of ≥35 weeks and their neonates who suffered from birth asphyxia from June 2016 to June 2021 were included in this retrospective study. Data regarding maternal demographic features, maternal laboratory values, pregnancy complications, and obstetric and neonatal outcomes were collected.

RESULTS

Significant risk factors associated with birth asphyxia were nulliparity (odds ratio [OR] = 5.357, 95% confidence interval [CI] = 2.169-24.950, p = 0.001), placental abruption (OR = 8.667, 95% CI = 2.223-33.784, p = 0.002), intrauterine growth restriction (OR = 1.394, 95% CI = 1.109-8.631, p = 0.012), the prolonged second stage of labor (OR = 6.121, 95% CI = 2.120-17.595, p = 0.001), meconium-stained amniotic fluid (OR = 7.615, 95% CI = 2.394-24.223, p = 0.001), bloody amniotic fluid (OR = 9.423, 95% CI = 2.885-35.232, p = 0.001), the presence of FHR category II (OR = 12.083, 95% CI = 7.081-48.849, p <0.001) and FHR category III before labor (OR = 15.500, 95% CI = 8.394-56.176, p <0.001).

CONCLUSION

We identified that nulliparity, placental abruption, intrauterine growth restriction, the prolonged second stage of labor, meconium-stained or bloody amniotic fluid, and FHR tracings categories II and III were significantly associated with birth asphyxia.

The Role of Magnetic Resonance in Evaluating Abdominopelvic Trauma - Part 2: Trauma in Pregnancy, Vascular, and Genitourinary Injuries

Trauma is an important cause of mortality, particularly in the young. While computed tomography (CT) is the mainstay of body imaging in the setting of trauma, magnetic resonance (MR) imaging can be useful in stable patients. Although more commonly used in spinal and musculoskeletal trauma, MR also has a role in abdominopelvic trauma. Broadly, its uses include clarification of equivocal cases, monitoring complications of trauma, particularly with solid organ injury, or as a primary imaging modality for patients with low suspicion for injury for whom avoiding ionizing radiation is a priority-namely, in pediatric and pregnant patients. In this two-part review article, we will review clinical scenarios where this may be encountered, utilizing case examples. Our second installment will focus on the use of MR in pregnant patients and in the characterization of vascular and genitourinary trauma. Body MR can be useful in pregnant patients in characterizing injuries both specific for and not specific for pregnancy. Placental injuries and hematomas in particular may be better seen on MR relative to CT, owing to its superior contrast resolution. MR angiography can be performed either without or with contrast and can be useful to monitor low-grade traumatic aortic injuries. Renal and ureteral injuries can be followed with MR to help identify urine leaks, either in a delayed presentation or in patients who have an iodinated contrast allergy. Lastly, penile injuries are often imaged with ultrasound, but may benefit from additional imaging with MR when the tunica albuginea cannot be completely seen due to overlying hematoma.

Role of Ultrasound in the Assessment and Differential Diagnosis of Pelvic Pain in Pregnancy

Pelvic pain (PP) is common in pregnant women and can be caused by several diseases, including obstetrics, gynaecological, gastrointestinal, genitourinary, and vascular disorders. Timely and accurate diagnosis as well as prompt treatment are crucial for the well-being of the mother and foetus. However, these are very challenging. It should be considered that the physiological changes occurring during pregnancy may confuse the diagnosis. In this setting, ultrasound (US) represents the first-line imaging technique since it is readily and widely available and does not use ionizing radiations. In some cases, US may be conclusive for the diagnosis (e.g., if it detects no foetal cardiac activity in suspected spontaneous abortion; if it shows an extrauterine gestational sac in suspected ectopic pregnancy; or if it reveals a dilated, aperistaltic, and blind-ending tubular structure arising from the cecum in suspicious of acute appendicitis). Magnetic resonance imaging (MRI), overcoming some limits of US, represents the second-line imaging technique when an US is negative or inconclusive, to detect the cause of bowel obstruction, or to characterize adnexal masses.

MRI in Pregnancy and Precision Medicine: A Review from Literature

Magnetic resonance imaging (MRI) offers excellent spatial and contrast resolution for evaluating a wide variety of pathologies, without exposing patients to ionizing radiations. Additionally, MRI offers reproducible diagnostic imaging results that are not operator-dependent, a major advantage over ultrasound. MRI is commonly used in pregnant women to evaluate, most frequently, acute abdominal and pelvic pain or placental abnormalities, as well as neurological or fetal abnormalities, infections, or neoplasms. However, to date, our knowledge about MRI safety during pregnancy, especially about the administration of gadolinium-based contrast agents, which are able to cross the placental barrier, is still limited, raising concerns about possible negative effects on both the mother and the health of the fetus. Contrast agents that are unable to cross the placenta in a way that is safe for the fetus are desirable. In recent years, some preclinical studies, carried out in rodent models, have evaluated the role of long circulating liposomal nanoparticle-based blood-pool gadolinium contrast agents that do not penetrate the placental barrier due to their size and therefore do not expose the fetus to the contrast agent during pregnancy, preserving it from any hypothetical risks. Hence, we performed a literature review focusing on contrast and non-contrast MRI use during pregnancy.

MRI based morphological examination of the placenta

Ultrasound is widely used as the initial diagnostic imaging modality during pregnancy with both high spatial and temporal resolution. Although MRI in pregnancy has long focused on the fetus, its use in placental imaging has greatly increased over recent years. In addition to the possibilities of evaluating function, MRI with a wide field of view and high contrast resolution allows characterization of placental anatomy, particularly in situations that are difficult to specify with ultrasound, especially for suspected placenta accreta. MRI also appears to be a particularly useful examination for the anatomical evaluation of the placenta independent of maternal body habitus or fetal position. Indeed, surprisingly little attention is paid to the placenta in MRI when the indication for the examination is fetal. Thus, some aspects of the placenta seem to us to be important to be recognized by the radiologist and to be described on the MRI report. In this review, we will describe MRI sequences used for, and common features seen in, imaging of i) the normal placenta, ii) abnormal aspects of the placenta that should be identified on MRI performed for fetal reason, and iii) placental anomalies for which placental MRI may be indicated.

Pictorial review of the postmortem computed tomography in neonaticide cases

Neonaticide is defined by the deliberate killing or homicide of a child within 24 h of its birth. In this context, three fundamental questions are generally asked of the forensic pathologist: what is the cause of death of the neonate? Was the child viable (i.e., what is the gestational age of the neonate)? Finally, was the neonate stillborn or liveborn?Postmortem imaging can help answer these questions by conducting (1) a complete lesional analysis of the body and the placenta, (2) an estimation of the gestational age by measuring the lengths of the diaphyseal long bones, and (3) an analysis of the aeration of the lungs and intestines. Using the details of 18 cases, we illustrate aspects of neonaticide cases in postmortem computed tomography (PMCT), offering detailed examples of notable postmortem changes and abnormalities, especially in the analysis of the pulmonary parenchyma. This article presents a useful iconography for the radiologist confronted with this rare yet complex forensic situation.

Prompt evaluation and treatment of third-trimester bleeding

ABSTRACT

Third-trimester bleeding is an obstetric emergency and is associated with significant maternal and fetal morbidity and mortality. The two most common causes for third-trimester bleeding are placental abruption and placenta previa, which account for about half of all cases. Clinicians should have a thorough understanding of the risk factors, clinical presentation, and appropriate management of these conditions. Timely management is necessary for the survival of mother and fetus and to reduce the incidence of neonatal complications.

Management of Placental Abruption Following Blunt Abdominal Trauma

Blunt abdominal trauma during pregnancy poses a significant risk to both the mother and fetus. Here, we review a case of a 21-year-old female at 17 weeks' gestation involved in a motor vehicle accident, who subsequently suffered a placental abruption and fetal demise secondary to the trauma. We present a review of traumatic placental abruptions, including epidemiology, laboratory findings, imaging, and management strategies. Because of associated maternal and fetal morbidity and mortality, it is imperative that health care professionals are well versed in the diagnosis, treatment, and acute care for this rare, yet high-risk scenario.

A Data-Driven Review of the Genetic Factors of Pregnancy Complications

Over the recent years, many advances have been made in the research of the genetic factors of pregnancy complications. In this work, we use publicly available data repositories, such as the National Human Genome Research Institute GWAS Catalog, HuGE Navigator, and the UK Biobank genetic and phenotypic dataset to gain insights into molecular pathways and individual genes behind a set of pregnancy-related traits, including the most studied ones—preeclampsia, gestational diabetes, preterm birth, and placental abruption. Using both HuGE and GWAS Catalog data, we confirm that immune system and, in particular, T-cell related pathways are one of the most important drivers of pregnancy-related traits. Pathway analysis of the data reveals that cell adhesion and matrisome-related genes are also commonly involved in pregnancy pathologies. We also find a large role of metabolic factors that affect not only gestational diabetes, but also the other traits. These shared metabolic genes include IGF2, PPARG, and NOS3. We further discover that the published genetic associations are poorly replicated in the independent UK Biobank cohort. Nevertheless, we find novel genome-wide associations with pregnancy-related traits for the FBLN7, STK32B, and ACTR3B genes, and replicate the effects of the KAZN and TLE1 genes, with the latter being the only gene identified across all data resources. Overall, our analysis highlights central molecular pathways for pregnancy-related traits, and suggests a need to use more accurate and sophisticated association analysis strategies to robustly identify genetic risk factors for pregnancy complications.

Nonfetal Imaging During Pregnancy: Placental Disease

Placenta is a vital organ that connects the maternal and fetal circulations, allowing exchange of nutrients and gases between the two. In addition to the fetus, placenta is a key component to evaluate during any imaging performed during pregnancy. The most common disease processes involving the placenta include placenta accreta spectrum disorders and placental masses. Several systemic processes such as infection and fetal hydrops can too affect the placenta; however, their imaging features are nonspecific such as placental thickening, heterogeneity, and calcifications. Ultrasound is the first line of imaging during pregnancy, and MR imaging is reserved for problem solving, when there is need for higher anatomic resolution.

Guidance for Evaluation and Management of Blunt Abdominal Trauma in Pregnancy

Blunt abdominal trauma is the leading type of traumatic injury in pregnancy, with motor vehicle crashes, falls, and assault being the most common etiologies. Several adverse outcomes can occur in pregnancy, including placental abruption, preterm labor and preterm delivery, uterine rupture, and pelvic fracture. Understanding and integration of key anatomic and physiologic changes in pregnancy are key when evaluating a pregnant trauma patient. Pregnant women should be managed in a medical center with the ability to provide adequate care to both trauma patients-the pregnant woman and fetus. Multiple clinical providers are usually involved in the care of pregnant trauma patients, but obstetric providers should play a central role in the evaluation and management of a pregnant trauma patient given their unique training, knowledge, and clinical skills. An algorithm for management of trauma in pregnancy should be used at all sites caring for pregnant women. An alignment of policies within each system optimizes appropriate triage, integration of care, management, and monitoring of pregnant trauma patients and their fetuses. Ensuring effective protocols for prehospital and hospital treatment, as well as thorough training of involved health care providers, is essential in ensuring that optimal care is provided.