Karin A. Fox

Center of excellence for placenta accreta

Placenta accreta spectrum is one of the most morbid conditions obstetricians will encounter. The incidence has dramatically increased in the last 20 years. The major contributing factor to this is believed to be the increase in the rate of cesarean delivery. Despite the increased incidence of placenta accreta, most obstetricians have personally managed only a small number of women with placenta accreta. The condition poses dramatic risk for massive hemorrhage and associated complication such as consumption coagulopathy, multisystem organ failure, and death. In addition, there is an increased risk for surgical complications such as injury to bladder, ureters, and bowel and the need for reoperation. Most women require blood transfusion, often in large quantities, and many require admission to an intensive care unit. As a result of indicated, often emergent preterm delivery, many babies require admission to a neonatal care intensive care unit. Outcomes are improved when delivery is accomplished in centers with multidisciplinary expertise and experience in the care of placenta accreta. Such expertise may include maternal-fetal medicine, gynecologic surgery, gynecologic oncology, vascular, trauma and urologic surgery, transfusion medicine, intensivists, neonatologists, interventional radiologists, anesthesiologists, specialized nursing staff, and ancillary personnel. This article highlights the desired features for a center of excellence in placenta accreta, and which patients should be referred for evaluation and/or delivery in such centers.

Effects of pravastatin on mediators of vascular function in a mouse model of soluble Fms-like tyrosine kinase-1-induced preeclampsia

OBJECTIVE We sought to investigate the mechanisms of action by which pravastatin improves vascular reactivity in a mouse model of preeclampsia induced by overexpression of soluble Fms-like tyrosine kinase-1 (sFlt)-1. STUDY DESIGN Pregnant CD-1 mice were randomly allocated to tail vein injection with adenovirus carrying sFlt-1 or murine immunoglobulin G2 Fc (control), and thereafter to receive pravastatin (5 mg/kg/d) or water. Mice were sacrificed at gestational day 18. Protein expression of endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor receptor-1, and hemeoxygenase-1 were assayed by Western blot in aorta, liver, and kidneys. Serum total cholesterol concentrations were measured. RESULTS Pravastatin up-regulated eNOS expression in the aorta of sFlt-1 mice by nearly 2-fold (P = .005) to levels similar to control mice. Total cholesterol levels, vascular endothelial growth factor receptor-1, and hemeoxygenase-1 protein expression were similar across groups. CONCLUSION Pravastatin prevents vascular dysfunction in part by up-regulation of eNOS in the vasculature. Our data support a role for statins in preeclampsia prevention.

Validation of the prediction model for success of vaginal birth after cesarean delivery

OBJECTIVE: To validate a previously developed vaginal birth after cesarean (VBAC) prediction model using a patient cohort different than that from which it was derived. METHODS: We performed a cohort study of all term pregnant women (January 2002–August 2007) with one prior low transverse cesarean delivery attempting a trial of labor. Variables used in the final prediction model (maternal age, prepregnancy body mass index, ethnicity, prior vaginal delivery, prior VBAC, and indication for prior cesarean delivery) were extracted from medical records and used to calculate an individual woman’s predicted VBAC success rate. These rates at the level of the study population then were partitioned into deciles and compared with the actual VBAC rates. RESULTS: Of 545 women who fit the inclusion criteria, 502 had complete data available. A total of 262 (52.2%) had VBAC. The predicted probability of VBAC, as calculated by the regression equation, was significantly higher in those who had a successful trial of labor (median 78.4%, interquartile range 62.1–88.2) than in those who did not (median 59.7%, interquartile range 50.8–75.3, P<.001). The predictive model had an area under the receiver operating characteristic of 0.70 (95% confidence interval 0.65–0.74, P<.001), which was similar to that originally described. The actual VBAC rates did not differ from the predicted rates when the predicted chance of success was less than 50%. Above a 50% predicted success, the achieved success rates were consistently 10–20% lower. CONCLUSION: The published nomogram is predictive of VBAC success. It may help pregnant women contemplating a trial of labor reach a more informed decision. LEVEL OF EVIDENCE: II

Conservative management of morbidly adherent placenta: expert review

Over the last century, the incidence of placenta accreta, increta, and percreta, collectively referred to as morbidly adherent placenta, has risen dramatically. Planned cesarean hysterectomy at the time of cesarean delivery is the standard recommended treatment in the United States. Recently, interest in conservative management has resurged, especially in Europe. The aims of this review are the following: (1) to provide an overview of methods used for conservative management, (2) to discuss clinical implications for both clinicians and patients, and (3) to identify areas in need of further research.

Preterm Premature Rupture of Membranes: Clinical Outcomes of Late-Preterm Infants

Objective: To determine gestational age-specific neonatal outcomes of late preterm infants delivered as a consequence of premature rupture of membranes (PROM). Methods: Retrospective cohort study of infants born to women delivered electively due to preterm PROM between 340/7 and 366/7 weeks of gestation. Neonatal outcomes were compared between those delivered at 340/7 to 34 6/7 weeks, at 350/7 to 356/7 weeks, and at 36 0/7 to 366/7 weeks. Results: 192 infants were identified. The 340/7 to 346/7 week infants had significantly higher neonatal intensive care admission rate (72.5%) compared to those at 35 0/7 to 356/7 weeks (22.8%) and at 36 to 366/7 weeks (17.8%) (P < .05). Neonatal respiratory distress syndrome was significantly higher at 340/7 to 346/7 weeks (35.4%) compared with 350/7 to 356/7 week and 360/7 to 36 6/7 week infants (10.5% and 4.1%; P < .05). The longest hospitalization occurred in the 340/7 to 346/7 week infants (248.5 ± 20.0 hours). Conclusion: Substantial short-term morbidity occurred in late preterm infants. The greatest number of complications affected infants born at 340/7 to 346/7 weeks.

Multidisciplinary team learning in the management of the morbidly adherent placenta: outcome improvements over time

BACKGROUND: Morbidly adherent placenta (MAP) is a serious obstetric complication causing mortality and morbidity. OBJECTIVE: To evaluate whether outcomes of patients with MAP improve with increasing experience within a well‐established multidisciplinary team at a single referral center. STUDY DESIGN: All singleton pregnancies with pathology‐confirmed MAP (including placenta accreta, increta, or percreta) managed by a multidisciplinary team between January 2011 and August 2016 were included in this retrospective study. Turnover of team members was minimal, and cases were divided into 2 time periods so as to compare 2 similarly sized groups: T1 = January 2011 to April 2014 and T2 = May 2014 to August 2016. Outcome variables were estimated blood loss, units of red blood cell transfused, volume of crystalloid transfused, massive transfusion protocol activation, ureter and bowel injury, and neonatal birth weight. Comparisons and adjustments were made by use of the Student t test, Mann‐Whitney U test, χ2 test, analysis of covariance, and multinomial logistic regression. RESULTS: A total of 118 singleton pregnancies, 59 in T1 and 59 in T2, were managed during the study period. Baseline patient characteristics were not statistically significant. Forty‐eight of 59 (81.4%) patients in T1 and 42 of 59 (71.2%) patients in T2 were diagnosed with placenta increta/percreta. The median [interquartile range] estimated blood loss (T1: 2000 [1475‐3000] vs T2: 1500 [1000‐2700], P = .04), median red blood cell transfusion units (T1: 2.5 [0‐7] vs T2: 1 [0‐4], P = .02), and median crystalloid transfusion volume (T1: 4200 [3600‐5000] vs T2: 3400 [3000‐4000], P < .01) were significantly less in T2. Also, a massive transfusion protocol was instituted more frequently in T1: 15/59 (25.4%) vs 3/59 (5.1%); P < .01. Neonatal outcomes and surgical complications were similar between the 2 groups. CONCLUSION: Our study shows that patient outcomes are improved over time with increasing experience within a well‐established multidisciplinary team performing 2−3 cases per month. This suggests that small, collective changes in team dynamics lead to continuous improvement of clinical outcomes. These findings support the development of centers of excellence for MAP staffed by stable, core multidisciplinary teams, which should perform a significant number of these procedures on an ongoing basis.

Robotic-Assisted, Ultrasound-Guided Abdominal Cerclage During Pregnancy: Overcoming Minimally Invasive Surgery Limitations?

Herein, we report robotic abdominal cerclage placement under ultrasound guidance. The da Vinci Si system (Intuitive Surgical, Sunnyvale, CA) allows a simultaneous display of the operative field and transvaginal ultrasound images. Additionally, the vaginal ultrasound probe assisted in the manipulation of the uterus to improve visualization without placing excessive pressure on the gravid uterus. Ultrasound guidance improves needle placement accuracy and reduces potential for injuries.

Vaccination in Pregnancy

The recent H1N1 influenza pandemic has highlighted the potential for viral infections to cause severe disease in mothers disproportionate to the general population and have deleterious effects on the fetus. Vaccines have been used in pregnant women for over 200 years. Current guidelines recommend vaccination with only inactivated virus due to potential risk to mother and fetus with live vaccine. The exception is during times of pandemic or biological weapons attack, when the risk of life-threatening disease outweighs the risk of vaccination. A paucity of data is available regarding actual risk and mechanisms of live viral vaccine transfer from mother to fetus. Pregnancy-induced changes to the maternal immune system, effects of maternal infection on neonatal immunity, and the role of the placenta in transmission of infection and passive immunity to the fetus are incompletely understood. The aim of this paper is to review available data pertaining to newer vaccines such as the pandemic H1N1 and HPV vaccines in pregnancy, the role of Fc receptors in active transport of immunoglobulin across the placenta, and cytokine activity during maternal infection and after vaccination. We will also discuss potential areas for future research.

Three-dimensional sonographic assessment of placental volume and vascularization in pregnancies complicated by hypertensive disorders.

The purpose of this study was to evaluate the association between placental volumes, placental vascularity, and hypertensive disorders in pregnancy.

Sex-specific effects of nicotine exposure on developmental programming of blood pressure and vascular reactivity in the C57Bl/6J mouse.

OBJECTIVE The objective of the study was to determine whether perinatal nicotine exposure adversely affects cardiovascular health in adulthood. STUDY DESIGN C57Bl/6J female mice were randomized to 200 μg/mL nicotine in 2% saccharin or 2% saccharin alone from 2 weeks before breeding until weaning. Offspring weight, vital signs, and carotid artery vascular reactivity were studied. A second cohort was subjected to shaker stress on day 4 of 7 days. Selected mediators of vascular tone were evaluated by molecular studies. Student t or Mann-Whitney U test was performed for statistical analysis (significance: P < .05). RESULTS Nicotine-exposed compared with control female offspring had significantly elevated mean blood pressure under normal and stress conditions. Nicotine females lacked heart rate elevation after stress. Nicotine males had higher mean heart rate and a blunted contractile response to phenylephrine compared with controls, without an increase in blood pressure. CONCLUSION Perinatal nicotine exposure has an impact on the developmental programming of future cardiovascular health, with adverse effects more evident in female offspring.