OBJECTIVES:This study compares maternal and neonatal outcomes between preterm vacuum and forceps-assisted vaginal births and evaluates preterm outcomes between those <34 + 0 weeks gestation to those ≥34 + 0. METHODS:This study is a single-center retrospective cohort study of all singleton assisted vaginal births during 2014-2021. Delivery data and data on neonatal and pregnant patient outcomes were extracted from electronic medical records. Categorical variables were described by frequencies and percentages, and adjusted odds ratios (aORs) were calculated using logistic regression. RESULTS:There were 5095 assisted vaginal births during this period, of which 246 were preterm (171 vacuum and 75 forceps assisted). Neonatal head ultrasounds were less common after preterm vacuum- than after preterm forceps-assisted births (6.4 vs. 13.3%). Of those under 34 weeks (18 vacuum and 18 forceps assisted), there were identical rates of head ultrasound in each group (n = 7, 38.9%). Rates of Grade 1 intraventricular hemorrhage were the same between the vacuum- and forceps-assisted groups under 34 weeks (n = 5, 27.7%). No major intra- or extra-cranial bleeds were found among infants who underwent a vacuum- or forceps-assisted birth before 34 weeks. Maternal outcomes showed significantly lower odds of obstetric anal sphincter injury (aOR 0.26) and episiotomy (aOR 0.16) with preterm vacuum compared to preterm forceps-assisted births. CONCLUSION:This study adds to a small but growing body of literature that supports maternal and neonatal safety of vacuum-assisted birth under 34 weeks' gestation, in comparison with the use of forceps, when assisted vaginal birth is required. Larger prospective registry-based studies are suggested to determine the robustness of this conclusion.

OBJECTIVE:Preeclampsia is a leading cause of maternal and fetal morbidity and mortality, but its clinical course is often difficult to predict. This can make management decisions, such as admission and administration of antenatal corticosteroids, challenging. Abnormal levels of the angiogenic proteins soluble fms-like tyrosine kinase 1 and placental growth factor have been shown to improve the diagnostic accuracy for preeclampsia. However, data on their accuracy in predicting time to delivery are limited. The objective of the present study was to fill this critical gap. STUDY DESIGN:A retrospective cohort study of patients with a singleton pregnancy in a single center evaluated for suspected preeclampsia using the Roche Elecsys soluble fms-like tyrosine kinase 1/placental growth factor ratio assay between 2020 and 2023. Modified Poisson regression and Cox regression survival analysis were used to estimate the association between the soluble fms-like tyrosine kinase 1/placental growth factor ratio and the risk of delivery within 7 days. The soluble fms-like tyrosine kinase 1/placental growth factor ratio was interpreted as low risk (≤38), moderate risk (>38-85), or high risk (>85). RESULTS:A total of 503 patients met the study criteria. The preeclampsia rate was 39.8% (n=200). The soluble fms-like tyrosine kinase 1/placental growth factor ratio was inversely associated with the testing-to-delivery time (Spearman's Rho, -0.63 [the confidence interval is -0.73 to 0.63]). Survival analysis revealed that moderate-risk and high-risk ratios were associated with shorter testing-to-delivery intervals than a low-risk ratio (adjusted hazard ratio, 1.7 [95% confidence interval, 1.2-2.3] and adjusted hazard ratio, 5.1 [95% confidence interval, 3.8-6.9], respectively). A low-risk ratio (≤38) was associated with a high negative predictive value for birth within 7 days (89% [95% confidence interval, 83%-96%]), especially when found before 34 weeks (99% [95% confidence interval, 97%-100%]). The positive predictive value of a high-risk ratio (>85) for delivery within 7 days was 65% (95% confidence interval, 56%-75%). To achieve a more clinically relevant positive predictive value of 80%, higher soluble fms-like tyrosine kinase 1/placental growth factor ratio cutoff values were required: 365 in the overall cohort, 368 in cases tested before 34 weeks, and 300 in those tested at ≥34 weeks. CONCLUSION:The soluble fms-like tyrosine kinase 1/placental growth factor ratio is a useful prognostic tool for predicting time to delivery in patients with suspected preeclampsia and can therefore guide management decisions, such as admission and the administration of antenatal corticosteroids.

Placenta accreta spectrum (PAS) is an obstetrical complication in which the placenta abnormally invades the uterine wall, increasing the risk of hemorrhage, surgical morbidity, and maternal mortality. Management is often complex and multidisciplinary, particularly when invasion extends beyond the uterus. For this reason, standardized guidelines are essential to support early diagnosis and coordinated care across specialties. Significant variations in clinical practice guidelines (CPGs) remain, especially between countries with differing levels of income. This systematic review evaluates national and international CPGs published within the last decade to identify areas of agreement, disagreement, and insufficient evidence across all stages of PAS care. To identify CPGs related to PAS, a comprehensive search of professional society websites, PubMed, the GIN Library, and the ECRI Guidelines Trust was conducted. Two independent reviewers evaluated the sources to extract relevant clinical recommendations, which were then sent to a panel of 15 to 18 experts who had authored their own PAS guidelines. During 2 rounds of structured feedback, the panel could comment on, clarify, or revise their own guidelines before the committee would evaluate them for consensus and sufficiency of evidence. Each guideline was categorized as demonstrating high agreement, poor consensus, or high levels of insufficient evidence. The data were visualized by quantifying the level of agreement and sorting each guideline into categories of epidemiology, diagnosis, antenatal management, surgical management, and postnatal care. A total of 18 articles from 14 national or international societies were included. There was high agreement on epidemiologic risk factors, diagnostic principles, and key elements of antenatal management. A history of cesarean delivery consistently emerged as a major risk factor, especially in patients with concurrent placenta previa. All guidelines supported ultrasound as the primary diagnostic tool, with most recommending standardized descriptors to enhance accuracy. Targeted second-trimester imaging was widely endorsed, with some guidelines supporting first-trimester screening for high-risk patients. There was also strong consensus surrounding antenatal management and the need for specialized care, emphasizing referral to tertiary centers with multidisciplinary expertise, adequate surgical and transfusion resources, and planned delivery around 34 to 35 weeks. In contrast, surgical and peripartum recommendations showed substantial variability and limited evidence, including uncertainty regarding optimal incision type, use of balloon occlusion catheters, anesthesia approaches, and conservative management strategies. Only 1 guideline offered specific recommendations for low- and middle-income countries. These findings indicate that while some aspects of PAS management, such as diagnosis and antenatal care, have a broad consensus, other areas remain under-investigated and lacking consensus. This is especially true for surgical and conservative management in the peripartum period and indicates a need for comparative research and international collaboration to develop standardization. In addition, PAS management in low- and middle-income countries, which often face resource limitations that require flexible and unique practices, is significantly limited. While further research and discussion are needed, this study provides a roadmap for global improvement in PAS management.

BACKGROUND:Umbilical artery Doppler plays a central role in the diagnosis and management of placenta-mediated early-onset fetal growth restriction. However, interpreting available data on the rate of umbilical artery Doppler progression remains challenging, primarily because many prior studies included patients with varying degrees of fetal growth restriction severity. Consequently, the aggregated data resulted in estimates of umbilical artery Doppler progression that are often too broad for clinical use. Therefore, there is a need for more robust data to define the deterioration rate of umbilical artery Doppler abnormalities in more homogeneous patient cohorts with definitive evidence of severe placenta-mediated early-onset fetal growth restriction. OBJECTIVE:To quantify the rate of progression of umbilical artery Doppler abnormalities, time to delivery, and risk of fetal death in a homogeneous cohort of singleton pregnancies with severe placenta-mediated early-onset fetal growth restriction that ultimately progressed to late umbilical artery Doppler abnormalities (defined as intermittent or persistent absent or reversed end-diastolic flow). STUDY DESIGN:We conducted a retrospective descriptive study of singleton pregnancies with severe early-onset fetal growth restriction that ultimately progressed to late umbilical artery Doppler abnormalities in a single tertiary center (2014-2024). Umbilical artery Doppler findings at each visit were categorized according to the following order of progression: normal (umbilical artery pulsatility index <95th percentile), elevated umbilical artery-pulsatility index (>95th percentile), intermittent absent end-diastolic flow, persistent absent end-diastolic flow, intermittent reversed end-diastolic flow, and persistent reversed end-diastolic flow. The primary outcomes were the timing of progression between successive umbilical artery Doppler abnormalities and the interval from each Doppler abnormality to either delivery or fetal death. RESULTS:A total of 241 patients met the study criteria and underwent 1835 Doppler assessments. The mean gestational age at which late umbilical artery Doppler abnormalities were first observed was 27.5±3.2 weeks, and the mean gestational age at birth was 28.6±3.1 weeks. Fetal death was observed in 11 pregnancies (4.6%), although the majority of these cases (10/11) were either previable (4/11) or occurred because the parents declined intervention due to poor prognosis (6/11). The mean±standard deviation time of umbilical artery Doppler progression was 7±8 days from elevated umbilical artery-pulsatility index to intermittent absent end-diastolic flow, 6±6 days from intermittent absent end-diastolic flow to absent end-diastolic flow, 6±6 days from absent end-diastolic flow to intermittent reversed end-diastolic flow, and 4±5 days from intermittent reversed end-diastolic flow to reversed end-diastolic flow. The time to delivery was greatest in cases of elevated umbilical artery-pulsatility index >95th percentile (median 6 [interquartile range, 3-12] days) or abnormal cerebral Doppler (5 [2-11] days) and was shorter for intermittent absent end-diastolic flow (4 [2-10] days), absent end-diastolic flow (3 [1-8] days), intermittent reversed end-diastolic flow (0 [0-3] days), and reversed end-diastolic flow (0 [0-1] days). The risk of observed fetal death increased progressively with the severity of umbilical artery Doppler abnormalities, from 0.6% in cases with intermittent absent end-diastolic flow to 11.5% in cases with reversed end-diastolic flow. All cases of observed fetal death showed evidence of either reversed end-diastolic flow in the umbilical artery or abnormal ductus venosus Doppler at the examination preceding fetal death. CONCLUSION:In this study, we provided estimates of umbilical artery Doppler deterioration rate, stage-specific fetal death risk, and time to delivery. Given the high-risk case mix, these intervals likely represent worst-case timelines and can therefore guide the minimum surveillance frequency, the timing of antenatal corticosteroid administration, and delivery timing planning. Patients and care providers can be reassured that the risk of fetal growth restriction-related fetal death between visits is low when neither reversed end-diastolic flow in the umbilical artery nor abnormal ductus venosus Doppler is present.

OBJECTIVE:To evaluate trends in hysterectomy case volume for placenta accreta spectrum (PAS) disorder over time and compare maternal outcomes between high- and low-volume centers. Specifically, we examined whether surgical volume influences severe maternal morbidity (SMM) and other key perioperative outcomes. METHODS:We conducted a population-based retrospective cohort study of patients aged 18-50 years who underwent hysterectomy for PAS in Ontario, Canada, from January 1, 2003, to January 1, 2022. Cases were identified using provincial administrative health databases. High-volume centers were defined as institutions performing ≥9 PAS hysterectomies annually, based on probability modeling and receiver operating characteristic analysis. The primary outcome was a validated composite measure of SMM, including massive transfusion, intensive care unit (ICU) admission, surgical complications, readmission, and length of hospital stay. RESULTS:Among 778 patients, 151 were treated at high-volume centers. These patients experienced significantly lower rates of SMM compared to those treated at low-volume centers (45.0% vs. 71.7%; adjusted relative risk [aRR] 0.59, 95% confidence interval [CI]: 0.49-0.72). Risks of massive transfusion (aRR 0.57, 95% CI: 0.47-0.70) and ICU admission (aRR 0.30, 95% CI: 0.15-0.58) were also markedly reduced. Length of hospital stay was shorter at high-volume centers (1.88 vs. 3.90 days; P < 0.0001). Each additional PAS hysterectomy performed in the prior year at a given institution was associated with a 3% reduction in SMM risk (aRR 0.97, 95% CI: 0.96-0.98). CONCLUSION:High-volume centers demonstrate significantly better maternal outcomes for PAS hysterectomy. These findings support centralizing PAS care to improve patient safety and surgical outcomes.

OBJECTIVE:To determine the risk of placental dysfunction associated with different ultrasound-based phenotypes of impaired fetal growth in dichorionic twin pregnancies. DESIGN:Retrospective cohort study. SETTING:Single tertiary centre. POPULATION:Patients with dichorionic twin pregnancies delivered at ≥ 320/7 (2011-2023) (N = 753). METHODS:Each twin fetus was classified into a distinct exposure group based on combinations of fetal weight percentile (categorised as AGA, mild SGA, or severe SGA) based on singleton- or twin-specific growth chart, weight discordance and Doppler. MAIN OUTCOME MEASURES:Abnormal placental histopathology known to be associated with FGR. RESULTS:The rate of the primary outcome in the reference group (AGA, concordant growth, normal Doppler) was 12.8%. When using a singleton chart, isolated discordance and mild SGA were not associated with the primary outcome. Only isolated severe SGA (28.8%, aRR 2.47[1.52-4.03]), followed by severe SGA with discordant growth (41.9%, aRR 3.53[2.15-5.79]) and abnormal Doppler (54.7%, aRR 4.33[2.90-6.48]) showed significant associations with the primary outcome. In contrast, when using a twin-specific chart, both isolated discordance (32.4%, aRR 2.63[1.46-4.73]) and mild SGA (28.2%, aRR 2.43[1.30-4.51]) were associated with the primary outcome. We propose three risk categories for late-onset placenta-mediated FGR based on the likelihood of the primary outcome: (1) possible small increase (< 2-fold); (2) moderate increase (2-3 fold); and (3) highest risk (> 4-fold). CONCLUSION:The risk categories proposed in the current study can serve as a framework to inform the design of future trials and contribute to the development of guidelines for managing twin pregnancies affected by late-onset FGR.

Importance:Placenta accreta spectrum (PAS) is a complex, life-threatening condition that demands a multidisciplinary approach involving obstetrics, maternal-fetal medicine, and various surgical and medical specialties. Effective management relies on multispecialty collaboration and consensus, supported by standardized protocols, to optimize outcomes, guide informed clinical decisions, and mitigate the risks associated with PAS. Objective:To examine clinical practice guidelines for PAS inclusive of high-income countries and low- to middle-income countries (LMICs) identifying areas of consensus and gaps in guidance. Evidence Review:A comprehensive search of PubMed, GIN Library, and ECRI Guidelines Trust identified all PAS-related clinical practice guidelines published from January 1, 2014, to January 31, 2024. Additional searches included professional societies' designated websites and cited references. Two independent reviewers screened the guidelines, resolving conflicts through cross-referencing. Initially, 2 independent reviewers provided structured review and feedback to refine, correct, or highlight areas of consensus, disagreement, or insufficient evidence. Any instances of nonagreement were adjudicated by majority panel agreement, arising from a panel of 15 to 18 experts, all authors of PAS guidelines. Agreement scores for each recommendation area (eg, epidemiology, diagnosis, and antenatal management) were categorized as high agreement (≥75%), poor consensus (<50% or ≥30% insufficient evidence), and high levels of insufficient evidence (≥50% of recommendations with insufficient evidence) based on a priori score criteria. Findings:A total of 14 guidelines from 18 articles from national and international societies were included. High agreement was noted in areas such as specialized expertise (100%), antenatal management (88.9%), diagnosis (76.9%), and epidemiology (75.0%). Poor consensus characterized cesarean hysterectomy management (38.5% insufficient evidence and 23.0% disagreement), conservative techniques (33.3% insufficient evidence and 11.1% disagreement), and fertility counseling (30.0% insufficient evidence and 10.0% disagreement). Despite the high risk of anemia, consensus was lacking on iron supplementation strategies. Recommendations for thromboembolism prevention varied, with some guidelines favoring pharmacologic interventions and others advocating for nonpharmacologic measures. Hemorrhage management and postnatal management recommendations, including iron supplementation and thromboembolism prevention, were characterized by high levels of insufficient evidence (55.6% and 57.1%, respectively). Only 1 article (5.6%) specifically addressed LMICs, highlighting substantial underrepresentation. Conclusions and Relevance:This systematic review of PAS guidelines identified significant discrepancies and insufficient evidence in key aspects of care. The findings underscore the urgent need for further research and quality measures to enhance standardized approaches and improve patient outcomes. The limited availability of recommendations applicable to LMICs highlights the critical need for tailored guidance that accounts for resource constraints and clinical access challenges unique to these settings.

There are numerous biomedical and psychosocial challenges associated with obesity in pregnancy that impede communication between healthcare providers (HCPs) and patients. We conducted a narrative study informed by stigma theory to understand specific areas of communication breakdown in obesity-in-pregnancy clinical encounters. Sixteen patients and 19 HCPs participated in in-depth, semi-structured interviews. We explored how participants positioned obesity-in-pregnancy clinical encounters within their broader narratives. Employing narrative analysis, we identified five narrative tensions contributing to communication challenges: 1) obesity as a detriment to health versus an acceptable biologic variation; 2) obesity as the result of personal choice versus the result of uncontrollable circumstances; 3) a regular pregnancy versus a high-risk diagnosis; 4) a typical and problem-free clinical encounter versus a tremendously difficult clinical encounter; and 5) talking openly about Body Mass Index (BMI) and related co-morbidities versus sidestepping the topic. How participants positioned themselves relative to prevailing societal discourses regarding obesity in general influenced these tensions. These narrative tensions revealed specific areas where communication is vulnerable to breaking down during the obesity-in-pregnancy clinical encounter. Participants' (both HCPs and patients) past experiences of clinical encounters-and the meanings they ascribe to them-shape subsequent encounters, and our analysis illuminates the complexities of this interactive space. This research has implications for improving clinical practice and education.

Over one‐quarter of women in the UK have a caesarean birth (CB). More than one in 20 of these caesarean births occurs near the end of labour, when the cervix is fully dilated (second stage). In these circumstances, and when labour has been prolonged, the baby's head can become lodged deep in the maternal pelvis making it challenging to deliver the baby. During the CB, difficulty in delivery of the baby's head may result—this emergency is known as impacted fetal head (IFH). These are technically challenging births that pose significant risks to both the woman and baby. Complications for the woman include tears in the womb, serious bleeding and longer hospital stays. Babies are at increased risk of injury including damage to the head and face, lack of oxygen to the brain, nerve damage, and in rare cases, the baby may die from these complications. Maternity staff are increasingly encountering IFH at CB, and reports of associated injuries have risen dramatically in recent years. The latest UK studies suggest that IFH may complicate as many as one in 10 unplanned caesarean births (1.5% of all births) and that two in 100 babies affected by IFH die or are seriously injured. Moreover, there has been a sharp increase in reports of babies having brain injuries when their birth was complicated by IFH. When an IFH occurs, the maternity team can use different approaches to help deliver the baby's head at CB. These include: an assistant (another obstetrician or midwife) pushing the head up from the vagina; delivering the baby's feet first; using a specially designed inflatable balloon device to elevate the baby's head and/or giving the mother a medicine to relax the womb. There has been a lack of consensus for how best to manage these births. [Correction added on 11 November 2025, after first online publication: The preceding sentence has been added in this version.] This has resulted in a lack of confidence among maternity staff, variable practice and potentially avoidable harm in some circumstances. This paper reviews the current evidence regarding the prediction, prevention and management of IFH at CB, integrating findings from a systematic review commissioned from the Avoiding Brain Injury in Childbirth (ABC) programme.

Objective: To determine whether a third-trimester drop in insulin requirements in pregnant people with pre-existing diabetes is associated with a subsequent occurrence of adverse pregnancy outcomes. Research Design and Methods: We conducted a retrospective cohort study of patients with type 1 and 2 diabetes who were followed at a tertiary referral center in Toronto, Canada. We collected data on insulin dosing in the third trimester (after 28 weeks of pregnancy) and compared outcomes in those with and without a third-trimester drop of 15% or more in their total insulin requirements. Our primary outcome was a composite of stillbirth, spontaneous preterm birth or preterm premature rupture of membranes, and iatrogenic preterm birth or cesarean birth for fetal wellbeing concerns, occurring following the drop in insulin requirements. We conducted regression analyses controlling for early pregnancy glycosylated hemoglobin, body mass index, and diabetes-related microvascular disease, and presented results as odds ratios (OR) with 95% confidence intervals (95%CI). Results: We included 350 pregnant people—146 with type 1 and 204 with type 2 diabetes. Of these, 54 (15.4%) had a third-trimester drop of 15% or more in their total insulin requirements. There was no difference in the primary outcome between groups (OR 0.97; 95% CI 0.41–2.10). Conclusions: Based on this single-center study, limited by sample size and analytic constraints, in people with pre-existing diabetes, a third-trimester drop of ≥15% in total insulin requirements was not associated with subsequent occurrence of adverse pregnancy outcomes. Larger prospective studies looking at associations between a drop in insulin requirements and subsequent occurrence of adverse pregnancy outcomes are necessary to inform meta-analyses and clinical decision making.

Fetal growth restriction (FGR) secondary to placental insufficiency often leads to morbidity and mortality in the perinatal period. Fetal adaptations such as "brain sparing" blood flow redistribution offer some protection, but predicting whether a fetus in this state will survive is challenging. The goal of this research was to identify vascular responses predictive of stillbirth or hypoxia based on serial Doppler ultrasound measurement in a mouse model of FGR. We performed serial Doppler ultrasound observations of fetal blood flow redistribution in a murine model of FGR, where prolongation of pregnancy was induced pharmacologically with progesterone in 56 CD-1 mice. Observations were made at E18.5 (physiologic term), E19.5 (term +1), and E20.5 (term +2). Flow velocity waveforms were obtained from the middle cerebral artery (MCA), ductus arteriosus (DA), main pulmonary artery (MPA), ductus venosus (DV), umbilical artery (UA), and umbilical vein (UV). Following euthanasia, pimonidazole immunohistochemistry quantified tissue hypoxia. Among 56 pregnancies, the strongest predictor of stillbirth was low DA peak systolic velocity at E19.5 (<217 mm/s, P = 0.021, R2 = 0.52). Among survivors, cerebral hypoxia was predicted by elevated MCA peak systolic (>26.6 mm/s, P = 0.022, R2 = 0.59) and end-diastolic velocity (>10.1 mm/s, P = 0.043, R2 = 0.53, whereas high MPA flow (>0.73 mL/min, P = 0.029, R2 = 0.51) predicted hepatic hypoxia. Overall, fetuses with a weaker pulmonary blood flow redistribution response were found to have worse outcomes, despite cerebral vasodilation. This minimally invasive murine model offers valuable insights into this pathophysiology of FGR-related stillbirth and highlights the prognostic potential of assessing fetal brain flow and pulmonary perfusion in tandem during sonographic surveillance of high-risk pregnancies.NEW & NOTEWORTHY Fetal growth restriction, often caused by placental disease, is an important cause of fetal injury and stillbirth. Understanding how the fetus adapts under these conditions is key to predicting survival. Here we report physiological adaptations in a mouse of model of fetal growth restriction that predict the risk of stillbirth.

Importance:Vasa previa, although a rare condition affecting 0.46 per 1000 pregnancies, results in high rates of fetal and neonatal mortality and morbidity. Widespread use of a core outcome set and reporting checklist may enable data harmonization, enhance evidence synthesis, and ensure prioritization of patient-important outcomes in clinical practice, future research, and clinical practice guidelines. Objective:To develop a core outcome set for studies on vasa previa that includes perinatal screening, diagnosis, and management of vasa previa. Design, Setting, and Participants:This survey study involved a 2-round international and cross-disciplinary Delphi survey and virtual consensus meetings conducted between March 14, 2021, and October 4, 2022. Health care professionals (HCPs) and health service users (HSUs) were invited to participate in the development of the core outcome set. Exposure:Perinatal screening, diagnosis, and management of vasa previa. Main Outcome and Measures:Core outcomes and reporting checklist items for future studies on vasa previa were developed using Delphi surveys, small group discussions, and a consensus meeting. Results:An international group of 204 participants, comprising 115 HSUs and 89 HCPs representing 27 countries, rated 67 outcomes identified through a systematic review and qualitative interviews in a 2-round online Delphi survey. Through virtual small group discussions and a consensus meeting, 13 core outcomes were identified: pregnancy outcome (live birth, fetal loss [miscarriage or stillbirth], or neonatal death), severe neonatal morbidity, fetal/neonatal blood loss, neonatal intensive care unit admission for >24 hours, gestational age at birth, third trimester confirmation of vasa previa diagnosis, neurocognitive and developmental outcomes, mode of birth, maternal death or severe morbidity, maternal quality of life, duration of antepartum admission, and antepartum or peripartum hemorrhage. A 22-item reporting checklist was simultaneously developed to include important items in studies on vasa previa when possible and/or relevant. Conclusions and Relevance:The core outcome set and reporting checklist for vasa previa are hoped to encourage researchers to incorporate patient-important outcomes in future studies to enable data harmonization, improve evidence synthesis, and facilitate the development of clinical practice guidelines for this rare and highly lethal condition for which timely diagnosis and management may prevent fetal and maternal morbidity and mortality.