Exome Sequencing for Prenatal Diagnosis in Nonimmune Hydrops Fetalis.

BACKGROUND: The cause of most fetal anomalies is not determined prenatally. Exome sequencing has transformed genetic diagnosis after birth, but its usefulness for prenatal diagnosis is still emerging. Nonimmune hydrops fetalis (NIHF), a fetal abnormality that is often lethal, has numerous genetic causes; the extent to which exome sequencing can aid in its diagnosis is unclear. METHODS: We evaluated a series of 127 consecutive unexplained cases of NIHF that were defined by the presence of fetal ascites, pleural or pericardial effusions, skin edema, cystic hygroma, increased nuchal translucency, or a combination of these conditions. The primary outcome was the diagnostic yield of exome sequencing for detecting genetic variants that were classified as either pathogenic or likely pathogenic according to the criteria of the American College of Medical Genetics and Genomics. Secondary outcomes were the percentage of cases associated with specific genetic disorders and the proportion of variants that were inherited. RESULTS: In 37 of the 127 cases (29%), we identified diagnostic genetic variants, including those for disorders affecting the RAS-MAPK cell-signaling pathway (known as RASopathies) (30% of the genetic diagnoses); inborn errors of metabolism and musculoskeletal disorders (11% each); lymphatic, neurodevelopmental, cardiovascular, and hematologic disorders (8% each); and others. Prognoses ranged from a relatively mild outcome to death during the perinatal period. Overall, 68% of the cases (25 of 37) with diagnostic variants were autosomal dominant (of which 12% were inherited and 88% were de novo), 27% (10 of 37) were autosomal recessive (of which 95% were inherited and 5% were de novo), 1 was inherited X-linked recessive, and 1 was of uncertain inheritance. We identified potentially diagnostic variants in an additional 12 cases. CONCLUSIONS: In this large case series of 127 fetuses with unexplained NIHF, we identified a diagnostic genetic variant in approximately one third of the cases. (Funded by the UCSF Center for Maternal-Fetal Precision Medicine and others; ClinicalTrials.gov number, NCT03412760.).

Histopathologic and Transcriptomic Profiling Identifies Novel Trophoblast Defects in Patients With Preeclampsia and Maternal Vascular Malperfusion.

Preeclampsia (PE) is a heterogeneous disease for which the current clinical classification system is based on the presence or absence of specific clinical features. PE-associated placentas also show heterogeneous findings on pathologic examination, suggesting that further subclassification is possible. We combined clinical, pathologic, immunohistochemical, and transcriptomic profiling of placentas to develop integrated signatures for multiple subclasses of PE. In total, 303 PE and 1388 nonhypertensive control placentas were included. We found that maternal vascular malperfusion (MVM) in the placenta was associated with preterm PE with severe features and with small-for-gestational-age neonates. Interestingly, PE placentas with either MVM or no histologic pattern of injury showed a linear decrease in proliferative (p63+) cytotrophoblast per villous area with increasing gestational age, similar to placentas obtained from the nonhypertensive patient cohort; however, PE placentas with fetal vascular malperfusion or villitis of unknown etiology lost this phenotype. This is mainly because of cases of fetal vascular malperfusion in placentas of patients with preterm PE and villitis of unknown etiology in placentas of patients with term PE, which are associated with a decrease or increase, respectively, in the cytotrophoblast per villous area. Finally, a transcriptomic analysis identified pathways associated with hypoxia, inflammation, and reduced cell proliferation in PE-MVM placentas and further subclassified this group into extravillous trophoblast-high and extravillous trophoblast-low PE, confirmed using an immunohistochemical analysis of trophoblast lineage-specific markers. Our findings suggest that within specific histopathologic patterns of placental injury, PE can be subclassified based on specific cellular and molecular defects, allowing the identification of pathways that may be targeted for diagnostic and therapeutic purposes.

FundAl Retroflexion (FAR) Angle is a Novel Sonographic Marker Associated With Cesarean Scar Pregnancies in the First Trimester: A Case-Control Study.

OBJECTIVES: Early diagnosis of Cesarean scar pregnancies (CSP) remains difficult. This study describes a novel sonographic marker, the FundAl Retroflexion (FAR) angle, that may be used in the first trimester. The objective of the study is to compare the FAR angle between CSP and normal pregnancies. METHODS: For this case-control study, we reviewed images from our institution's database that were acquired from January 2016 to December 2019. All cases of CSP and randomly selected controls, defined as patients with history of Cesarean delivery and normal implantation, that underwent ultrasound evaluation at <14 weeks were included. The FAR angle, defined as the acute angle created between the endometrial echo and cervical canal, was measured. The mean FAR angle was then compared between the two groups and a receiver operating characteristic (ROC) curve was generated. RESULTS: We identified 15 cases of CSP during the study period and were able to measure the FAR angle in 14 of the cases. The mean FAR angle was larger in CSP than in normal control pregnancies (45° versus 27°, respectively, P < 0.001). Using an ROC curve, a FAR angle cut off of 40° maximizes the ability to distinguish between CSP from normal pregnancies. CONCLUSIONS: The FAR angle provides an easily obtainable and numerical measurement. CSP have larger FAR angle compared to normal controls with a distinguishing cut off of 40°. Larger studies are needed to determine if using the FAR angle can improve first trimester diagnosis for CSP.

Antibiotic Therapy for Chorioamnionitis to Reduce the Global Burden of Associated Disease.

Chorioamnionitis is associated with significant maternal and neonatal morbidity and mortality throughout the world. In developed countries, great progress has been made to minimize the impact of chorioamnionitis, through timely diagnosis and appropriate treatment. In the global setting, where many women deliver outside the healthcare facilities, this diagnosis is frequently overlooked and not properly treated. In addition to its impact on maternal health, a significant proportion of neonatal morbidity and mortality can be prevented by both recognition and access to readily available treatment. With the increasing focus on saving the most vulnerable members of society, we echo the need for providing parturient women with suspected chorioamnionitis universal access to appropriate therapy. We describe known effective antibiotic therapies for chorioamnionitis and provide an overview of additional potential antimicrobial treatments that might be effectively implemented in areas with limited access to care.

Distinguishing Arterial Ischemic Stroke From Hypoxic-Ischemic Encephalopathy in the Neonate at Birth.

OBJECTIVE: To identify perinatal risk factors that can distinguish arterial ischemic stroke from hypoxic-ischemic encephalopathy at birth. METHODS: This is a cohort study of all neonates born at 35 weeks of gestation or greater admitted to our neonatal intensive care unit from January 1, 2010, to December 31, 2015, that compares neonates with stroke with those with hypoxic-ischemic encephalopathy undergoing whole-body hypothermia with abnormal brain magnetic resonance imaging. RESULTS: During this 6-year period, there were 22 neonates with stroke and 47 with hypoxic-ischemic encephalopathy undergoing whole-body hypothermia with abnormal magnetic resonance imaging. Three neonates triaged to hypothermia initially thought to have hypoxic-ischemic encephalopathy were later diagnosed with stroke. All neonates with stroke had a negative thrombophilia workup. Neonates with stroke had a significantly higher incidence of seizures and increased initial platelet counts on univariate analysis. A multivariable model of variables with P<.1 on univariate analysis present within 6 hours of birth found significant increases in nonreassuring fetal heart rate tracings, sentinel events, low Apgar score at 5 minutes, and metabolic acidosis at birth with hypoxic-ischemic encephalopathy. Stroke was associated with a significantly increased initial platelet count. CONCLUSION: Stroke is associated with increased initial platelet counts and is not associated with cesarean delivery for nonreassuring fetal heart rate tracings, sentinel events, or perinatal metabolic acidosis. Stroke is a form of neonatal brain injury not associated with perinatal risk factors that allow early identification.

Diagnostic accuracy of fetal heart rate monitoring in the identification of neonatal encephalopathy.

OBJECTIVE: To estimate the diagnostic accuracy of electronic fetal heart rate abnormalities in the identification of neonates with encephalopathy treated with whole-body hypothermia. METHODS: Between January 1, 2007, and July 1, 2013, there were 39 neonates born at two hospitals within our system treated with whole-body hypothermia within 6 hours of birth. Neurologically normal control neonates were matched to each case by gestational age and mode of delivery in a two-to-one fashion. The last hour of electronic fetal heart rate monitoring before delivery was evaluated by three obstetricians blinded to outcome. RESULTS: The differences in tracing category were not significantly different (neonates in the case group 10.3% I, 76.9% II, 12.8% III; neonates in the control group 9.0% I, 89.7% II, 1.3% III; P=.18). Bivariate analysis showed neonates in the case group had significantly increased late decelerations, total deceleration area 30 (debt 30) and 60 minutes (debt 60) before delivery and were more likely to be nonreactive. Multivariable logistic regression showed neonates in the case group had a significant decrease in early decelerations (P=.03) and a significant increase in debt 30 (.01) and debt 60 (P=.005). The area under the receiver operating characteristic curve, sensitivity, and specificity were 0.72, 23.1%, and 94.9% for early decelerations; 0.66, 33.3%, and 87.2% for debt 30, and 0.68, 35.9%, and 89.7% for debt 60, respectively. CONCLUSION: Abnormalities during the last hour of fetal heart rate monitoring before delivery are poorly predictive of neonatal hypoxic-ischemic encephalopathy qualifying for whole-body hypothermia treatment within 6 hours of birth. LEVEL OF EVIEDENCE: II.