Pharmacologic venous thromboembolism prophylaxis for preterm prelabor rupture of membranes.

BACKGROUND: Pregnant patients with preterm prelabor rupture of membranes may experience prolonged hospitalization, which is an indication for pharmacologic venous thromboembolism prophylaxis according to certain international guidelines. The proportion of patients who deliver unexpectedly and within a period during which pharmacologic prophylaxis would be expected to impact coagulation is unknown. OBJECTIVES: To estimate the proportion of patients with preterm prelabor rupture of membranes who would deliver within 12 hours of typical dosing of pharmacologic venous thromboembolism prophylaxis if administered routinely for antepartum admissions >72 hours. STUDY DESIGN: This is a retrospective cohort study from a database including patients admitted for expectant management of preterm prelabor rupture of membranes January 2011-September 2020. The outcome of the study was the proportion of patients who remained undelivered 72 hours after admission and experienced an unplanned delivery potentially within 12 hours of enoxaparin administration. We evaluated patients undelivered after 72 hours due to international recommendations to initiate venous thromboembolism prophylaxis in hospitalized patients after 72 hours. Unplanned delivery was defined as onset of spontaneous labor or other indication for immediate delivery. Timing of delivery was analyzed based on usual timing of enoxaparin administration daily at approximately 8 am and the recommendation to withhold regional anesthesia until 12 hours after a prophylactic dose. RESULTS: 1381 deliveries were identified as preterm prelabor rupture of membranes out of the 49,322 deliveries in our database. 139 cases were included after the following exclusions: delivery >35 weeks (N=641), rupture of membranes >34 weeks (N=145), delivery <72 hours after admission (N=409), insufficient data (N=35), and duplicates (N=12). Sixty of the 139 (43%) had an unplanned delivery, while 33 of these (24% of total) occurred within 12 hours of enoxaparin administration. CONCLUSION: A quarter of patients admitted for preterm prelabor rupture of membranes had an unplanned delivery within 12 hours of typical enoxaparin dosing. This cohort may experience harm (ineligibility for regional anesthesia, risks of general anesthesia, increased risk of bleeding) if given routine pharmacologic venous thromboembolism prophylaxis. Risk/benefit considerations should be discussed with patients in considering pharmacologic versus mechanical prophylaxis during prolonged hospitalization for preterm prelabor rupture of membranes.

Clinical exome sequencing uncovers genetic disorders in neonates with suspected hypoxic-ischemic encephalopathy: A retrospective analysis.

Hypoxic-ischemic encephalopathy (HIE) occurs in up to 7 out of 1000 births and accounts for almost a quarter of neonatal deaths worldwide. Despite the name, many newborns with HIE have little evidence of perinatal hypoxia. We hypothesized that some infants with HIE have genetic disorders that resemble encephalopathy. We reviewed genetic results for newborns with HIE undergoing exome or genome sequencing at a clinical laboratory (2014-2022). Neonates were included if they had a diagnosis of HIE and were delivered ≥35 weeks. Neonates were excluded for cardiopulmonary pathology resulting in hypoxemia or if neuroimaging suggested postnatal hypoxic-ischemic injury. Of 24 patients meeting inclusion criteria, six (25%) were diagnosed with a genetic condition. Four neonates had variants at loci linked to conditions with phenotypic features resembling HIE, including KIF1A, GBE1, ACTA1, and a 15q13.3 deletion. Two additional neonates had variants in genes not previously associated with encephalopathy, including DUOX2 and PTPN11. Of the six neonates with a molecular diagnosis, two had isolated HIE without apparent comorbidities to suggest a genetic disorder. Genetic diagnoses were identified among neonates with and without sentinel labor events, abnormal umbilical cord gasses, and low Apgar scores. These results suggest that genetic evaluation is clinically relevant for patients with perinatal HIE.

Umbilical cord gas analysis: clinical implications of a comprehensive, contemporary determination of normal ranges.

BACKGROUND: Umbilical cord gases are often used to assess the impact of labor and delivery on the fetus. However, no large series exists that reflects contemporary obstetrical practice or that analyzed blood gas ranges by route of delivery. Baseline, prelabor acid-base status in the human fetus is also poorly defined, rendering the assessment of blood gas changes during labor difficult. OBJECTIVE: This study aimed to define normal umbilical cord gas and lactate values, stratified by mode of delivery, in a large contemporary series in which universal umbilical cord gas evaluation was dictated by protocol. STUDY DESIGN: This was a retrospective cohort study. We analyzed the umbilical cord gas and lactate data of an unselected population of infants born between March 2012 and April 2022 at a large teaching hospital. These values were then analyzed by mode of delivery and, for cesarean deliveries, by indication for cesarean delivery and type of anesthesia. Umbilical cord gas values from infants delivered by elective cesarean delivey under general anesthesia without labor were considered representative of baseline, prelabor values. RESULTS: Data were available for 45,475 infants. The median arterial pH values and interquartile ranges for vaginal births, elective cesarean deliveries without labor, and cesarean deliveries performed for fetal heart rate concerns were 7.27 (0.09), 7.27 (0.06), and 7.25 (0.09), respectively. Arterial lactate values for these same 3 groups were 4.1 (2.5), 2.5 (1.2), and 4.0 (2.8) mmoles/L, respectively. Because of the very large sample size, most comparisons yielded differences that were statistically significant, but clinically irrelevant. Of all the infants, 14% had an arterial pH <7.20; a pH value of 7.1 represents 2 standard deviations from the mean. CONCLUSION: This large, population-based study of umbilical cord gas and lactate levels in an unselected population, stratified by delivery mode, represents a previously unavailable benchmark for the evaluation of umbilical cord gases. Arterial umbilical cord pH values for infants delivered by elective caesarean delivery without labor (median pH 7.28) reflect a lower prelabor fetal pH baseline than previously assumed. This finding, coupled with our determination that a 2 standard deviation below normal pH limit of 7.1, instead of the historic arbitrary pH of 7.2 threshold, helps to explain the poor positive predictive value of electronic fetal heart rate monitoring, a test designed to detect arterial pH levels that have fallen from an assumed baseline near pH 7.4 to an assumed potentially injurious pH level of <7.2. Uncomplicated labor, even when prolonged, does not generally lead to a clinically significant cumulative hypoxic stress to the human fetus. These findings, along with our determination that there is no difference in the acid-base status among infants delivered by cesarean delivery for fetal heart rate concerns, help to explain the failure of current approaches in labor and delivery management to reduce the rates of neonatal hypoxic-ischemic encephalopathy and cerebral palsy, conditions that almost always reflect developmental events rather than the effects of labor on the fetus.

Massive Transfusion Protocols in Obstetric Hemorrhage: Theory versus Reality.

OBJECTIVE: Massive transfusion protocols are widely implemented in obstetrical practice in case of severe hemorrhage; however, different recommendations exist regarding the appropriate ratios of blood product components to be transfused. We report our extensive experience with massive component transfusion in a referral center in which the standard massive transfusion protocol is modified by ongoing clinical and laboratory evaluation. STUDY DESIGN: A retrospective chart review of all patients who had massive transfusion protocol activation in a level 4 referral center for obstetrical practice was performed from January 2014 to January 2020. Data collected included the etiology of obstetrical hemorrhage, number of blood products of each type transfused, crystalloid infusion, and several indices of maternal morbidity and mortality. Data are presented with descriptive statistics. RESULTS: A total of 62 patients had massive transfusion protocol activation, of which 97% received blood products. Uterine atony was found to be the most common etiology for massive hemorrhage (34%), followed by placenta accreta spectrum (32%). The mean estimated blood loss was 1,945 mL. A mean of 6.5 units of packed red blood cells, 14.8 units of fresh frozen plasma and cryoprecipitate, and 8.3 units of platelets were transfused per patient. No maternal deaths were seen. CONCLUSION: The ratios of transfused packed red blood cell to fresh frozen plasma/cryoprecipitate and of packed red blood cell to platelet units varied significantly from the fixed initial infusion ratio called for by our massive transfusion protocol resulting in universally favorable maternal outcomes. When rapid laboratory evaluation of hematologic and clotting parameters is available, careful use of this information may facilitate safe modification of an initial fixed transfusion ratio based on etiology of the hemorrhage and individual patient response. KEY POINTS: · Massive transfusion protocols in obstetrics follow fixed ratios of blood products.. · Actual usage of blood components is different than the standardized protocols.. · We recommend to modify the initial fixed transfusion ratio according to clinical response..

Gestational hypertension and "severe" disease: time for a change.

Our understanding and management of gestational hypertension and its variants are substantially hindered by a reliance on antiquated terminology and on practice recommendations based largely on tradition rather than outcomes-based evidence. Unsurprisingly, gestational hypertension remains a major contributor to maternal and neonatal morbidity and mortality rates, with little improvement seen over the past half century except as it relates to better newborn care. Reliance on a binary classification of vastly disparate types and degrees of organ dysfunction (severe or not severe) and the use of nonphysiological and largely arbitrary gestational age cutoffs are particularly problematic. If this situation is to improve, it will be necessary to abandon current misleading terminology and non-evidence-based traditional practice patterns and start again, building on management approaches validated by outcomes-based data.

The Association between Placenta Accreta Spectrum Severity and Incidence of Small for Gestational Age Neonates.

OBJECTIVE: The aim of the study is to evaluate whether pathologic severity of placenta accreta spectrum (PAS) is correlated with the incidence of small for gestational age (SGA) and neonatal birthweight. STUDY DESIGN: This was a multicenter cohort study of viable, non-anomalous, singleton gestations delivered with histology-proven PAS. Data including maternal history, neonatal birthweight, and placental pathology were collected and deidentified. Pathology was defined as accreta, increta, or percreta. The primary outcome was rate of SGA defined by birth weight less than the 10th percentile. The secondary outcomes included incidence of large for gestational age (LGA) babies as defined by birth weight greater than the 90th percentile as well as incidence of SGA and LGA in preterm and term gestations. Statistical analysis was performed using Chi-square, Kruskal-Wallis, and log-binomial regression. Increta and percreta patients were each compared with accreta patients. RESULTS: Among the cohort of 1,008 women from seven United States centers, 865 subjects were included in the analysis. The relative risk (RR) of SGA for increta and percreta did not differ from accreta after adjusting for confounders (adjusted RR = 0.63, 95% confidence interval [CI]: 0.36-1.10 for increta and aRR = 0.72, 95% CI: 0.45-1.16 for percreta). The results were stratified by placenta previa status, which did not affect results. There was no difference in incidence of LGA (p = 1.0) by PAS pathologic severity. The incidence of SGA for all PAS patients was 9.2% for those delivered preterm and 18.7% for those delivered at term (p = 0.004). The incidence of LGA for all PAS patients was 12.6% for those delivered preterm and 13.2% for those delivered at term (p = 0.8203). CONCLUSION: There was no difference in incidence of SGA or LGA when comparing accreta to increta or percreta patients regardless of previa status. Although we cannot suggest causation, our results suggest that PAS, regardless of pathologic severity, is not associated with pathologic fetal growth in the preterm period. KEY POINTS: · PAS severity is not associated with SGA in the preterm period.. · PAS severity is not associated with LGA.. · Placenta previa does not affect the incidence of SGA in women with PAS..

Category II Intrapartum Fetal Heart Rate Patterns Unassociated With Recognized Sentinel Events: Castles in the Air.

The evolution of continuous electronic fetal heart rate (FHR) monitoring has presented the obstetrician with a critical clinical conundrum: basic science observations suggest that such monitoring might be associated with improved long-term neurologic outcomes, yet, after a half century of use and millions of cesarean deliveries based on FHR monitoring, evidence for such improvement remains absent. This dichotomy appears to be related to widespread misconceptions regarding the physiology underlying various FHR patterns and the developmental origins of cerebral palsy. These misconceptions are strengthened by a reliance on anecdotal experience and tradition in lieu of evidence-based medicine, the confusing "category II" FHR designation, medical-legal considerations, and our tendency to view fetal monitoring, as originally conceptualized, as a single, indivisible entity whose concepts must be accepted or rejected en bloc. Ill-defined and largely imaginary conditions such as "depletion of fetal reserve" are particularly harmful and their use in clinical medicine uniquely not evidence based. A solution to this self-inflicted injury to our specialty will require a concerted effort involving teachers, authors, and researchers.

The Society for Pediatric Pathology Task Force grading system for placenta accreta spectrum and its correlation with clinical outcomes.

BACKGROUND: The terminology and diagnostic criteria presently used by pathologists to report placenta accreta spectrum is inconsistent and does not reflect current knowledge of the pathogenesis of this disease. OBJECTIVE: In 2020, the perinatal subcommittee of the Society for Pediatric Pathology Placenta Accreta Task Force proposed a new pathologic grading system for placenta accreta spectrum. We sought to correlate the clinical outcomes with the classification into each group in the new placenta accreta spectrum grading system. STUDY DESIGN: The pathology reports of patients with histopathologic confirmation of placenta accreta spectrum were reviewed in 2 academic referral centers by placental pathologists. Pathologic grading was assigned based on the new grading system according to which placenta accreta spectrum is categorized into 5 groups depending on the depth of invasion, from grade p1 with no invasion into the uterine wall to grade p3E with invasion beyond the uterine wall to the adjacent organs. Patient characteristics and clinical outcomes were compared among these groups. A univariate analysis was performed, and a multivariate linear or binomial regression was employed when needed. RESULTS: A total of 683 patients with placenta accreta spectrum were identified. Of those, 407 were included for histology review. There were 92 patients (23%) categorized into the grade p1 group, 74 (18%) in the grade p2 group, 84 (20%) in the grade p3A group, 121 (30%) in the grade p3D group, and 36 (9%) in the grade p3E group. There was a significant association between the pathology grading and the number of red blood cells transfused (ß=1.14; 95% confidence interval, 0.48-1.79) and the postoperative complications including the rate of readmission (risk ratio, 1.93; 95% confidence interval, 1.26-2.94) and bladder injury (risk ratio, 1.81; 95% confidence interval, 1.23-2.68) after adjustment for antenatal diagnosis and other variables. The pathology grading was not associated with the estimated blood loss (P=.072). CONCLUSION: The new pathology grading system accurately reflects maternal outcomes and complications of placenta accreta spectrum. We encourage the utilization of this new pathologic grading system because it is designed to omit discrepancies in placenta accreta spectrum reporting and to standardize communication.

Intrapartum ultrasound measurement of angle of progression at the onset of the second stage of labor for prediction of spontaneous vaginal delivery in term singleton pregnancies: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to investigate the diagnostic performance of transperineal ultrasound-measured angles of progression at the onset of the second stage of labor for the prediction of spontaneous vaginal delivery in singleton term pregnancies with cephalic presentation. DATA SOURCES: We performed a predefined systematic search in PubMed, Embase, Scopus, Web of Science, and Google Scholar from inception to February 5, 2021. STUDY ELIGIBILITY CRITERIA: Prospective cohort studies that evaluated the diagnostic performance of transperineal ultrasound-measured angles of progression (index test) at the onset of the second stage of labor (ie, when complete cervical dilation is diagnosed) for the prediction of spontaneous vaginal delivery (reference standard) were eligible for inclusion. Eligible studies were limited to those published as full-text articles in the English language and those that included only parturients with a singleton healthy fetus at term with cephalic presentation. STUDY APPRAISAL AND SYNTHESIS METHODS: Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Summary receiver operating characteristic curves, pooled sensitivities and specificities, area under the curve, and summary likelihood ratios were calculated using the Stata software. Subgroup analyses were done based on angle of progression ranges of 108° to 119°, 120° to 140°, and 141° to 153°. RESULTS: A total of 8 studies reporting on 887 pregnancies were included. Summary estimates of the sensitivity and specificity of transperineal ultrasound-measured angle of progression at the onset of the second stage of labor for predicting spontaneous vaginal delivery were 94% (95% confidence interval, 88%-97%) and 47% (95% confidence interval, 18%-78%), respectively, for an angle of progression of 108° to 119°, 81% (95% confidence interval, 70%-89%) and 73% (95% confidence interval, 57%-85%), respectively, for an angle of progression of 120° to 140°, and 66% (95% confidence interval, 56%-74%) and 82% (95% confidence interval, 66%-92%), respectively, for an angle of progression of 141° to 153°. Likelihood ratio syntheses gave overall positive likelihood ratios of 1.8 (95% confidence interval, 1-3.3), 3 (95% confidence interval, 2-4.7), and 3.7 (95% confidence interval, 1.7-8.1) and negative likelihood ratios of 0.13 (95% confidence interval, 0.07-0.22), 0.26 (95% confidence interval, 0.18-0.38), and 0.42 (95% confidence interval, 0.29-0.60) for angle of progression ranges of 108° to 119°, 120° to 140°, and 141° to 153°, respectively. CONCLUSION: Angle of progression measured by transperineal ultrasound at the onset of the second stage of labor may predict spontaneous vaginal delivery in singleton, term, cephalic presenting pregnancies and has the potential to be used along with physical examinations and other clinical factors in the management of labor and delivery.

Urologic morbidity associated with placenta accreta spectrum surgeries: single-center experience with a multidisciplinary team.

BACKGROUND: Hysterectomy for placenta accreta spectrum may be associated with urologic morbidity, including intentional or unintentional cystostomy, ureteral injury, and bladder fistula. Although previous retrospective studies have shown an association between placenta accreta spectrum and urologic morbidities, there is still a paucity of literature addressing these urologic complications. OBJECTIVE: We sought to report a systematic description of such morbidity and associated factors. STUDY DESIGN: This was a retrospective study of all histology-proven placenta accreta spectrum deliveries in an academic center between 2011 and 2020. Urologic morbidity was defined as the presence of at least one of the following: cystotomy, ureteral injury, or bladder fistula. Variables were reported as median (interquartile range) or number (percentage). Analyses were made using appropriate parametric and nonparametric tests. Multinomial regression analysis was performed to assess the association of adverse urologic events with the depth of placental invasion. RESULTS: In this study, 58 of 292 patients (19.9%) experienced urologic morbidity. Patients with urologic morbidity had a higher rate of placenta percreta (compared with placenta accreta and placenta increta) than those without such injuries. Preoperative ureteral stents were placed in 54 patients (93.1%) with and 146 patients (62.4%) without urologic injury (P=.003). After adjusting for confounding variables, multinomial regression analysis revealed that the odds of having adverse urologic events was 6.5 times higher in patients with placenta percreta than in patients with placenta accreta. CONCLUSION: Greater depth of invasion in placenta accreta spectrum was associated with more frequent and severe adverse urologic events. Whether stent placement confers any protective benefit requires further investigation.

Clinical Outcomes of a False-Positive Antenatal Diagnosis of Placenta Accreta Spectrum.

OBJECTIVE: Antenatal diagnosis of placenta accreta spectrum (PAS) is critical to reduce maternal morbidity. While clinical outcomes of women with PAS have been extensively described, little information is available regarding the women who undergo cesarean delivery with a presumptive PAS diagnosis that is not confirmed by histopathologic examination. We sought to examine resource utilization and clinical outcomes of this group of women with a false-positive diagnosis of PAS. STUDY DESIGN: This is a retrospective analysis of patients with prenatally diagnosed PAS cared for between 2015 and 2020 by our multidisciplinary PAS team. Maternal outcomes were examined. Univariate analysis was performed and a multivariate model was employed to compare outcomes between women with and without histopathologically confirmed PAS. RESULTS: A total of 162 patients delivered with the preoperative diagnosis of PAS. Of these, 146 (90%) underwent hysterectomy and had histopathologic confirmation of PAS. Thirteen women did not undergo the planned hysterectomy. Three women underwent hysterectomy but pathologic examination did not confirm PAS. In comparing women with and without pathologic confirmation of PAS, the false-positive PAS group delivered later in pregnancy (34 vs. 33 weeks of gestation, p = 0.015) and had more planned surgery (88 vs. 47%, p = 0.002). There was no difference in skin incision type or hysterotomy placement for delivery. No significant difference in either the estimated blood loss or blood components transfused was noted between groups. CONCLUSION: Careful intraoperative evaluation of women with preoperatively presumed PAS resulted in a 3/149 (2%) retrospectively unnecessary hysterectomy. Management of women with PAS in experienced centers benefits patients in terms of both resource utilization and avoidance of unnecessary maternal morbidity, understanding that our results are produced in a center of excellence for PAS. We also propose a management protocol to assist in the avoidance of unnecessary hysterectomy in women with the preoperative diagnosis of PAS. KEY POINTS: · Evaluation and delivery planning of patients with suspected placenta accreta spectrum in experienced centers provides acceptable outcomes.. · Under specific circumstances, delivery of placenta may be attempted if placenta accreta is suspected.. · Patients with suspected placenta accreta rarely undergo unindicated hysterectomy..

Relationship Between Umbilical Cord Gas Values and Neonatal Outcomes: Implications for Electronic Fetal Heart Rate Monitoring.

OBJECTIVE: To evaluate the relationship between umbilical artery cord gas values and fetal tolerance of labor, as reflected by Apgar score. We hypothesized the existence of wide biological variability in fetal tolerance of metabolic acidemia, which, if present, would weaken one fundamental assumption underlying the use of electronic fetal heart rate (FHR) monitoring. METHODS: We conducted a retrospective cohort study of term, singleton, nonanomalous fetuses delivered in our institution between March 2012 and July 2020. Universally obtained umbilical cord gas values and Apgar scores were extracted. We calculated Spearman correlation coefficients and receiver operating characteristic curves for various levels of umbilical artery pH, base excess, and Apgar scores. RESULTS: We analyzed data from 29,787 deliveries. The statistical correlation between umbilical artery pH and base excess and both 1- and 5-minute Apgar scores was weak or nonexistent in all pH range subgroups (range 0.064-0.213). Receiver operating characteristic curve analysis suggested umbilical artery pH value of 7.22 yields the best discrimination for prediction of a severely depressed newborn (5-minute Apgar score less than 4), but sensitivity and specificity for this predictive value remains poor to moderate. CONCLUSION: The use of electronic FHR monitoring is predicated on a documented relationship between FHR patterns and umbilical artery pH, and an assumed correlation between pH and fetal outcomes, reflecting fetal tolerance of labor and delivery. Our data demonstrate a weak-to-absent correlation between metabolic acidemia and even short-term fetal condition, thus significantly weakening this latter assumption. No amount of future modification of FHR pattern interpretation to better predict newborn pH is likely to lead to improved newborn outcomes, given this weakness in a fundamental assumption on which FHR monitoring is based.

Trimester-specific thromboelastic values and coagulation activation markers in pregnancy compared across trimesters and compared to the nonpregnant state.

INTRODUCTION: Rotational thromboelastometry (ROTEM) rapidly identifies deficits underlying coagulopathy during massive hemorrhage. Prompt coagulopathy correction is balanced with the risk of blood product overutilization, making the ability to quickly target therapy highly desirable. However, data about ROTEM reference ranges in pregnancy are limited. We hypothesized that ROTEM parameters change across trimesters of pregnancy and differ from the nonpregnant state. Also, we sought to identify which hemostatic test best predicts coagulation activation during pregnancy. METHODS: A prospective cohort study in healthy pregnant patients in the first (n = 34), second (n = 34), and third trimesters (n = 41) against healthy, nonpregnant controls (n = 33) was performed. Citrated blood was collected, and ROTEM, complete blood count, and plasma-based assays of coagulation were performed. Mean ± SD or median [IQR] were compared across trimesters and between each trimester against the nonpregnant state. ROTEM parameters vs. plasma-based assays were also compared. RESULTS: Maximum clot firmness and A10 in FIBTEM correlated strongly with fibrinogen level. INTEM and EXTEM values demonstrated only weak to modest correlation with corresponding tests using plasma assays. Thrombin antithrombin complex (TAT) increased from the first trimester onward, whereas other coagulation activation markers did not show difference compared with control group. CONCLUSION: Rotational thromboelastometry parameters differ variably across trimesters of pregnancy and compared with the nonpregnant state. The development and use of pregnancy-specific values are critical to the proper clinical interpretation of ROTEM in women with serious hemorrhage during different stages in pregnancy. TAT was the earliest laboratory marker for coagulation activation among others.

Neuropathophysiology of preeclampsia and eclampsia: A review of cerebral hemodynamic principles in hypertensive disorders of pregnancy.

Preeclampsia and eclampsia are hypertensive disorders of pregnancy associated with abnormal placental vascular development. The systemic angiogenic imbalance, endothelial dysfunction and proinflammatory state caused by abnormal placental development results in abnormalities in renal, hepatic, pulmonary and neurologic function. Neurosensory symptoms related to pregnancy induced hypertension (PIH), the most devastating of which are intracranial hemorrhage and seizure, are among the leading causes of maternal and perinatal morbidity and mortality globally, yet risk stratification strategies and targeted therapies remain elusive. Current treatment for preeclampsia with severe features is limited to delivery, antihypertensive therapy, and magnesium sulfate seizure prophylaxis. Magnesium sulfate reduces seizure rates among severe preeclamptics, but predisposes patients to weakness, uterine atony, pulmonary edema and respiratory depression. Therefore, this drug should ideally be administered only to the subset of preeclamptics who are at increased risk for neurologic complications. While there are no objective methods validated to predict eclampsia, we hypothesize that measurement of optic nerve sheath diameters, optic disc height and middle cerebral artery transcranial doppler resistance indices may be useful in identifying subclinical cerebral edema, potentially allowing us to recognize those patients at highest risk for seizures. This summary of the current literature provides an initial framework for developing more sophisticated and noninvasive methods for identifying, monitoring and treating parturients who are at highest risk for neurologic complications from preeclampsia.