Ventricular tachycardia converts to sinus rhythm after administration of propofol.

Ventricular tachycardia (VT) is a major contributor to sudden cardiac death, and pharmacologic treatment options beyond antiarrhythmics are limited. Emerging data suggest sympathetic blocking agents such as propofol are a potential management option for VT refractory to first line antiarrhythmics. Previous literature has described fixed-dose propofol boluses and continuous infusions to convert ventricular arrhythmias; however, to our knowledge, there are no reports of a weight-based dosing strategy for VT. We present the case of a patient with amiodarone-refractory VT who received a 1 mg/kg propofol bolus in preparation for cardioversion and subsequently converted to normal sinus rhythm. The patient stabilized following these interventions, transferred to a tertiary care facility, and was discharged home with an implantable cardioverter defibrillator.

Treatment of Hypothermic Cardiac Arrest in the Pediatric Drowning Victim, a Case Report, and Systematic Review.

OBJECTIVES: Drowning is the second leading cause of death in children. Extracorporeal membrane oxygenation (ECMO) has become the criterion standard therapy to resuscitate the hypothermic drowning victim in cardiac arrest. We present our own experience treating 5 children with hypothermic cardiac arrest in conjunction with a systematic review to analyze clinical features predictive of survival. METHODS: Our search resulted in 55 articles. Inclusion criteria were as follows: (1) younger than 18 years, (2) ECMO therapy, and (3) drowning. Ten articles met our inclusion criteria. We included studies using both central and peripheral ECMO and salt or fresh water submersions. We compared clinical features of survivors to nonsurvivors. RESULTS: A total of 29 patients from the 10 different studies met our criteria. Data analyzed included presenting cardiac rhythm, time to initiation of ECMO, submersion time, pH, potassium, lactate, duration of chest compressions, and survival. There was a significant increase in mortality for presenting rhythm of asystole and with hyperkalemia (P < 0.05). CONCLUSIONS: Extracorporeal membrane oxygenation is an important resuscitation tool for the hypothermic drowning victim. Hyperkalemia and presenting cardiac rhythm correlate with survival although they are not reasons to end resuscitation. More studies are needed to compare the outcomes in using ECMO for the hypothermic drowning victim.

Cell-free DNA fetal fraction in twin gestations in single-nucleotide polymorphism-based noninvasive prenatal screening.

OBJECTIVES: The performance of noninvasive prenatal screening (NIPS) for fetal aneuploidy in twin pregnancies is dependent on the amount of placentally derived cell-free DNA, the "fetal fraction (FF)," present in maternal plasma. We report FF values in monozygotic (MZ) and dizygotic (DZ) pregnancies. METHODS: We reviewed FF in pregnancies at 10 to 20 completed weeks gestational age based on single-nucleotide polymorphism (SNP)-based NIPS where zygosity was routinely established in twin pregnancies. The cohort included 121 446 (96.3%) singleton, 1454 (1.2%) MZ, and 3161 (2.5%) DZ pregnancies. For DZ twins, individual FFs were measured. RESULTS: Combined FF for DZ and MZ fetuses were 35% and 26% greater than singletons, respectively. The individual FF contributions from each fetus in DZ twins were, on average, 32% less than singletons. FF in DZ twin pairs were moderately correlated (Pearson correlation coefficient.66). When a threshold of 2.8% FF was applied to define uninterpretable results, 1.7% (2102/121 446) of singletons, 0.8% (11/1454) of MZ pairs, and 5.6% (178/3161) of DZ pairs were uninterpretable. CONCLUSION: For optimal aneuploidy NIPS in twin pregnancies, zygosity should be established and in DZ twins FF for both fetuses should be determined to identify those cases where results can be reliably interpreted.

The Association between Fetal Fibronectin, Cervical Length, and Amniotic Fluid Sludge with Histological Indicators of Placental Inflammation in Twin Gestations.

OBJECTIVE: The objective of this study was to evaluate the association of screening tests for preterm birth (short cervical length [CL], positive fetal fibronectin (FFN), and amniotic fluid [AF] sludge) in twin gestations with histologic evidence of placental inflammation. STUDY DESIGN: Historical cohort study of 596 twin gestations delivered in a single maternal-fetal medicine practice with CL and FFN testing from 22 to 256/7 weeks. A short CL was defined as ≤25 mm. Placental lesions evaluated were chronic and acute membrane inflammation and funisitis. Fischer's exact test and logistic regression were used. RESULTS: None of the screening tests was associated with chronic inflammation. All were associated with acute inflammation. On regression analysis, a short CL and positive FFN remained independently associated with acute inflammation (adjusted odds ratio [aOR]: 5.66 and 2.51, respectively) and funisitis (aOR: 5.66 and 7.17, respectively). AF sludge was not independently associated with acute inflammation nor funisitis. CONCLUSION: In twin gestations, a short CL and a positive FFN at 22 to 26 weeks are associated with acute but not chronic inflammation on placental histology. These findings imply that mechanisms underlying preterm birth in twins that result in positive screening tests weeks prior to delivery are not reflected as chronic placental inflammation. Therefore, pathologic interpretation of etiologic mechanisms for preterm birth may be limited using solely histologic reports.

Peritoneal dialysis catheter placement, outcomes and complications.

PURPOSE: Peritoneal dialysis (PD) is a commonly used method for renal support in pediatric patients and can be associated with the risk of post-surgical complications. We evaluated method of placement of PD catheters with regard to post-surgical complications. METHODS: PD catheters placed at two institutions between 2005 and 2017 were reviewed. Complication rates were evaluated based on method of placement, delayed usage, omentectomy, and patient age using Fisher's exact test, two-sided, with significance set at 0.05. Factors influencing complication were evaluated with multivariate logistic regression and Kaplan-Meier survival analysis. RESULTS: There were 130 patients with 157 catheters placed, ranging in age from 1 day to 23 years. There was no significant difference in complication rate by method of placement or delayed usage. Infants were significantly more likely to experience leakage (21% vs 8%, p 0.036) and hernias (15% vs 5%, p 0.030). Patients that underwent an omentectomy were less likely to require a catheter replacement (7% vs 27%, p 0.004), and the catheters had a significantly higher survival rate (p 0.009). We found that laparoscopic intervention resulted in catheter salvage. Lateral exit sites may be a risk factor for catheter migration in some patients. CONCLUSIONS: Omentectomy is associated with longer PD catheter survival. Laparoscopic salvage of dysfunctional catheters may be a valuable adjunct in management.

Risk factors for blood transfusion in patients undergoing high-order Cesarean delivery.

BACKGROUND: The objective was to identify risk factors associated with blood transfusion in patients undergoing high-order Cesarean delivery (CD). STUDY DESIGN AND METHODS: This was a retrospective cohort study of patients undergoing third or more CD by a single maternal-fetal medicine practice between 2005 and 2016. We compared risk factors between women who did and did not receive a red blood cell transfusion during the operation or before discharge. Repeat analysis was performed after excluding women with placenta previa. RESULTS: A total of 514 patients were included, 18 of whom (3.5%; 95% confidence interval [CI], 2.2%-5.5%) received a blood transfusion. Placenta previa was the most significant risk factor for transfusion (61.1% of patients who received a transfusion vs. 1% of patients who did not; p < 0.001). Patients with a placenta previa had a 68.8% likelihood of requiring a blood transfusion. After women who had placenta previa were excluded, the incidence of blood transfusion was seven of 498 (1.4%; 95% CI, 0.7%-2.9%). Risk factors significantly associated with blood transfusion in the absence of previa were prophylactic anticoagulation during pregnancy and having labored. The incidence of transfusion in patients with no placenta previa, no anticoagulation, and no labor was 0.7% (95% CI, 0.3%-2.1%). Placenta previa was the most predictive risk factor for transfusion with a positive predictive value of 68.8% and a negative predictive value of 98.4%. CONCLUSION: In patients undergoing a third or more CD, only placenta previa, prophylactic anticoagulation during pregnancy, and having labored are independently associated with requiring a blood transfusion. These data can be used to guide physician ordering of prepared blood products preoperatively.

Intraoperative temperature regulation in children using a liquid-warming garment.

PURPOSE: Children undergoing operative intervention while induced under general anesthesia are at risk for experiencing a significant decrease in core body temperature that can lead to adverse systemic effects. Given that the head contributes an estimated 18% of a child's body surface area, we theorized that a liquid-warming garment applied to the head could control a pediatric patient's core body temperature during surgical procedures. METHODS: Patients undergoing elective, non-cranial, general surgical procedures were enrolled in the study. A head garment with an embedded network of tubing was placed on the patient. The garment connected to a computer-controlled water bath that managed the temperature of the water in the tubing through a feedback mechanism. RESULTS: Ten patients with ages ranging from 1 day to 3 years (mean age 10.5 months) were enrolled in this study. The average procedure length was 82.5 min. The mean core body temperature throughout the procedure for all-comers was 36.5 ± 0.9 °C with an overall mean difference in maximum and minimum temperatures of 1.32 ± 1.1 °C. CONCLUSION: A liquid-warming garment applied to the head of pediatric surgical patients is an innovative and relatively low-cost means to regulate and to maintain the ideal core body temperature of patients undergoing surgical procedures.

Sonographic appearance of a cesarean scar pregnancy with placenta percreta invading the bladder in the first trimester and management with fertility preservation.

A 36-year-old, gravida 8, para 6, woman with six prior cesarean sections presented at 6 weeks with a cesarean scar pregnancy. Medical management was performed initially; however, subsequent three-dimensional sonographic examinations revealed trophoblastic invasion into the bladder. This led to robotic-assisted partial cystectomy, fulguration of invaded pregnancy, and repair of the uterine defect. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:163-167, 2017.

The Independent Association of a Short Cervix, Positive Fetal Fibronectin, Amniotic Fluid Sludge, and Cervical Funneling with Spontaneous Preterm Birth in Twin Pregnancies.

Objective To estimate the independent association of a short cervical length (CL), positive fetal fibronectin (fFN), amniotic fluid (AF) sludge, and cervical funneling with spontaneous preterm birth in twin pregnancies. Methods Retrospective cohort study of twin pregnancies managed by a single maternal-fetal medicine practice from June 2005 to February 2014. All patients underwent transvaginal sonographic CL and fFN testing. We reviewed all images from the first CL at 22(0/7) to 25(6/7) weeks for the presence of (1) a short CL, which is defined as ≤25 mm, (2) AF sludge, and (3) cervical funneling, and also recorded (4) the fFN result from that time. Image reviewers were blinded to pregnancy outcomes. Patients with cerclage were excluded. Using logistic regression, we calculated the independent association between these four biomarkers and spontaneous preterm birth. Results A total of 635 patients with twin pregnancies were included. The markers independently associated with spontaneous preterm birth <35 weeks were short CL (adjusted odds ratio [aOR]: 10.73; 95% confidence interval [CI]: 3.21-35.81), positive fFN (aOR: 3.25; 95% CI: 1.13-9.33), and AF sludge (aOR: 2.11; 95% CI: 1.04-4.27). Similarly, these three markers were independently associated with earlier gestational ages at delivery. Cervical funneling was not independently associated with spontaneous preterm birth <35 weeks nor gestational age at delivery. The risk of spontaneous preterm birth increased significantly with the number of positive biomarkers (short CL, positive fFN, and AF sludge). Conclusion In twin pregnancies, a short CL, positive fFN, and AF sludge are independently associated with spontaneous preterm birth. Cervical funneling is not independently associated with spontaneous preterm birth in twins.

Chromosomal microarray versus karyotyping for prenatal diagnosis.

BACKGROUND: Chromosomal microarray analysis has emerged as a primary diagnostic tool for the evaluation of developmental delay and structural malformations in children. We aimed to evaluate the accuracy, efficacy, and incremental yield of chromosomal microarray analysis as compared with karyotyping for routine prenatal diagnosis. METHODS: Samples from women undergoing prenatal diagnosis at 29 centers were sent to a central karyotyping laboratory. Each sample was split in two; standard karyotyping was performed on one portion and the other was sent to one of four laboratories for chromosomal microarray. RESULTS: We enrolled a total of 4406 women. Indications for prenatal diagnosis were advanced maternal age (46.6%), abnormal result on Down's syndrome screening (18.8%), structural anomalies on ultrasonography (25.2%), and other indications (9.4%). In 4340 (98.8%) of the fetal samples, microarray analysis was successful; 87.9% of samples could be used without tissue culture. Microarray analysis of the 4282 nonmosaic samples identified all the aneuploidies and unbalanced rearrangements identified on karyotyping but did not identify balanced translocations and fetal triploidy. In samples with a normal karyotype, microarray analysis revealed clinically relevant deletions or duplications in 6.0% with a structural anomaly and in 1.7% of those whose indications were advanced maternal age or positive screening results. CONCLUSIONS: In the context of prenatal diagnostic testing, chromosomal microarray analysis identified additional, clinically significant cytogenetic information as compared with karyotyping and was equally efficacious in identifying aneuploidies and unbalanced rearrangements but did not identify balanced translocations and triploidies. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and others; ClinicalTrials.gov number, NCT01279733.).

Risk factors for cesarean delivery in twin pregnancies attempting vaginal delivery.

OBJECTIVE: The purpose of this study was to estimate independent risk factors for cesarean delivery in patients with twin pregnancies who attempt vaginal delivery. STUDY DESIGN: This was an historic cohort of twin pregnancies that were delivered in 1 practice from June 2005 to February 2014. Baseline characteristics were compared between women who delivered vaginally and women who underwent cesarean delivery in labor. Logistic regression analysis was performed to estimate independent risk factors for cesarean delivery. RESULTS: Two hundred eighty-six women with twin pregnancies who had attempted vaginal delivery were included in the study. The overall modes of delivery were vaginal delivery (82.2%), cesarean delivery (17.8%), and combined vaginal-cesarean delivery (0%). The most common indication for cesarean delivery in labor was an arrest disorder (82.4%). The risk factors that were associated independently with cesarean delivery were nulliparity (adjusted odds ratio, 5.78; 95% confidence interval, 2.24-14.88) and advanced maternal age of ≥35 years (adjusted odds ratio, 2.36; 95% confidence interval, 1.16-4.80). The patients at highest risk for cesarean delivery (nulliparous, advanced maternal age, induced labor) still had a 48.6% likelihood of vaginal delivery. CONCLUSION: In patients with twin pregnancies who attempt labor, nulliparity and advanced maternal age are associated independently with cesarean delivery in labor. However, even the patients at highest risk for cesarean delivery have nearly a 50% likelihood of successful vaginal delivery and therefore should be allowed to attempt vaginal delivery if it is desired and not otherwise contraindicated.

Expression of periplasmic chaperones in Salmonella Typhimurium reduces its viability in vivo.

The efficacy of live attenuated bacterial vectors is dependent upon the fine-tuning of a strain's immunogenicity and its virulence. Strains are often engineered to deliver heterologous antigens, but soluble expression of recombinant proteins can be troublesome. Therefore, secretion systems or chaperone proteins are routinely used to assist in attaining high levels of functional, soluble protein production. However, the effects of chaperone expression on the virulence of attenuated bacterial vectors have not been previously reported. In anticipation of utilizing periplasmic chaperone proteins to facilitate soluble production of immunomodulatory proteins in an attenuated strain of Salmonella Typhimurium, the production of the chaperones was tested for their effect on both culture growth and bacterial persistence in mouse tissues. Although no effect on growth of the bacteria was observed in vitro, the increased expression of the periplasmic chaperones resulted in over-attenuation of the Salmonella in vivo.

Antenatal Surveillance in Twin Pregnancies Using the Biophysical Profile.

Objectives-The nonstress test is currently the most widely used modality for antenatal surveillance in twin pregnancies, with a quoted false-positive rate of 11%-12%. Our objective was to report our experience with the sonographic portion of the biophysical profile in twin pregnancies as the primary screening modality.Methods-Women with twin pregnancies delivered by a single maternal-fetal medicine practice from 2005 to 2013 were included. We excluded monoamniotic twins. Twin pregnancies began weekly sonography for the biophysical profile starting at 32 to 33 weeks, or earlier if indicated. The nonstress test was performed if the sonographic biophysical profile score was less than 8 of 8. We reviewed biophysical profile scores and outcomes for all patients who delivered at 33 weeks or later to assess the false-positive rate for the biophysical profile, as well as the incidence of intrauterine fetal death (IUFD) after initiation of antenatal surveillance.Results-A total of 539 twin pregnancies were included. The incidence of IUFD per patient was 2 per 539 (0.4%; 95% confidence interval [CI], 0.1%-1.3%), and the incidence of IUFD per fetus was 2 per 1078 (0.19%; 95% CI, 0.05%-0.7%). The overall positive screen rate was 24 per 539 (4.45%; 95% CI, 3.0%-6.5%). The false-positive screen rate, defined as an abnormal biophysical profile that did not diagnose an IUFD or lead to delivery, was 10 per 539 (1.9%; 95% CI, 1.0%-3.4%).Conclusions-In twin pregnancies the use of the sonographic biophysical profile for routine antenatal surveillance has a low false-positive rate, with a very low incidence of IUFD. The sonographic biophysical profile should be considered as a primary mode for antenatal surveillance in twin pregnancies, with a reflex nonstress test for an abnormal score.

Gestational age at cervical length and fetal fibronectin assessment and the incidence of spontaneous preterm birth in twins.

OBJECTIVES: To estimate the risk of spontaneous preterm birth in twin pregnancies based on transvaginal sonographic cervical length, fetal fibronectin (fFN) testing, and the gestational age at which these tests were performed. METHODS: Women with twin pregnancies, cervical length assessment, and fFN testing between 22 weeks and 31 weeks 6 days in a single maternal-fetal medicine practice from 2005 to 2013 were included. All testing was done on asymptomatic women on an out-patient basis. Women with monochorionic monoamniotic twins and twin-twin transfusion were excluded. Logistic regression analysis was used to estimate the risk of spontaneous preterm birth before 35, 32, and 28 weeks. RESULTS: Six hundred eleven patients were included and underwent a total of 2406 cervical length measurements and 2279 fFN tests over the course of the study period. The likelihood values for spontaneous preterm birth before 35, 32, and 28 weeks were 19.1%, 6.3%, and 2.3%, respectively. The risk of spontaneous preterm birth before 35 weeks increased with a decreasing cervical length (coefficient for the log of the odds ratio [OR coefficient], -0.13; P < .01; 95% confidence interval [CI], -0.22 to -0.037), a positive fFN result (OR coefficient, 1.04; P < .01; 95% CI, 0.45 to 1.64), as well as earlier gestational ages at testing (OR coefficient, -0.214; P < .01; 95% CI, -0.33 to -0.10). Similar results were seen for spontaneous preterm birth before 32 and 28 weeks. CONCLUSIONS: In asymptomatic patients with twin pregnancies, the cervical length, fFN, and gestational age are all significantly associated with spontaneous preterm birth.

Abnormal Biochemical Analytes Used for Aneuploidy Screening and Adverse Pregnancy Outcomes in Twin Gestations.

OBJECTIVE: The objective of this study was to determine if first- and second-trimester biochemical markers for aneuploidy have an association with adverse pregnancy outcomes in twin gestations. STUDY DESIGN: A retrospective cohort study of patients who presented with dichorionic diamniotic twin gestations was performed. Patients with first-trimester low pregnancy-associated plasma protein A (PAPP-A) or low free ß human chorionic gonadotropin (ß-hCG), or second-trimester elevated α-fetoprotein (AFP), elevated inhibin A, elevated hCG, or low unconjugated estradiol were identified. The rates of adverse pregnancy outcomes were compared between patients with or without abnormal analytes with p < 0.05 used as significance. RESULTS: In this study, 340 pregnancies were included. Patients with a low PAPP-A had an increased risk for delivery < 37 weeks. Patients with an elevated second-trimester hCG had an increased risk for spontaneous delivery < 28 weeks and neonatal intensive care unit (NICU) admission. Patients with an elevated inhibin A had an increased risk of spontaneous delivery at < 37 and NICU admission. Patients with an elevated AFP had an increased risk of a NICU admission. CONCLUSION: Certain abnormal aneuploidy markers are associated with an increased risk of adverse pregnancy outcomes in twin gestations.

Is MSAFP still a useful test for detecting open neural tube defects and ventral wall defects in the era of first-trimester and early second-trimester fetal anatomical ultrasounds?

INTRODUCTION: To evaluate whether maternal serum α-fetoprotein (MSAFP) improves the detection rate for open neural tube defects (ONTDs) and ventral wall defects (VWD) in patients undergoing first-trimester and early second-trimester fetal anatomical survey. MATERIAL AND METHODS: A cohort of women undergoing screening between 2005 and 2012 was identified. All patients were offered an ultrasound at between 11 weeks and 13 weeks and 6 days of gestational age for nuchal translucency/fetal anatomy followed by an early second-trimester ultrasound at between 15 weeks and 17 weeks and 6 days of gestational age for fetal anatomy and MSAFP screening. All cases of ONTD and VWD were identified via query of billing and reporting software. Sensitivity and specificity for detection of ONTD/VWD were calculated, and groups were compared using the Fisher exact test, with p < 0.05 as significance. RESULTS: A total of 23,790 women met the criteria for inclusion. Overall, 15 cases of ONTD and 17 cases of VWD were identified; 100% of cases were diagnosed by ultrasound prior to 18 weeks' gestation; none were diagnosed via MSAFP screening (p < 0.001). First-trimester and early second-trimester ultrasound had 100% sensitivity and 100% specificity for diagnosing ONTD/VWD. DISCUSSION: Ultrasound for fetal anatomy during the first and early second trimester detected 100% of ONTD/VWD in our population. MSAFP is not useful as a screening tool for ONTD and VWD in the setting of this ultrasound screening protocol.

Soluble production of a biologically active single-chain antibody against murine PD-L1 in Escherichia coli.

Programmed death ligand 1 (PD-L1), is an important regulator of T-cell activation and has emerged as an important target for cancer immunotherapy. Single chain variable fragments (scFvs) have several desirable characteristics and are an attractive alternative to monoclonal antibodies for experimental or therapeutic purposes. Three chickens were immunized against murine PD-L1, and mRNA isolated from their spleens was used to generate an immunized immunoglobulin variable region library. Using splice-overlap extension PCR, variable region cDNAs were combined to generate full-length scFvs. M13 phage display of the resulting scFv library identified a functional scFv against PD-L1 (αPD-L1 scFv). The scFv was expressed as soluble protein in the periplasm and culture supernatant of recombinant Escherichia coli and purified with a 6×-His tag using immobile metal affinity chromatography. The dissociation constant of αPD-L1 scFv was determined to be 7.11×10(-10)M, and the scFv demonstrated inhibitory biological activity comparable to an antagonistic monoclonal antibody, providing an alternative agent for blocking PD-1/PD-L1 signaling.

The relationship between preeclampsia and intrauterine growth restriction in twin pregnancies.

OBJECTIVE: Preeclampsia and intrauterine growth restriction (IUGR) are correlated in singleton pregnancies. The objective of this study was to estimate their relationship in twin pregnancies. STUDY DESIGN: Cohort of 578 patients with twin pregnancies delivered by 1 maternal fetal medicine practice from 2005-2013. Patients with chronic hypertension, monochorionic-monoamniotic placentation, twin-twin transfusion, and major congenital anomalies were excluded. Standard definitions were used for gestational hypertension and preeclampsia. We defined IUGR as any twin birthweight less than the 5th percentile for gestational age, as well as any twin birthweight less than the 10th percentile for gestational age. RESULTS: The incidence of preeclampsia was 14.9%, the incidence of birthweight <10% was 50.0%, and the incidence of birthweight <5% was 27.5%. Comparing patients with and without preeclampsia, the rate of birthweight <5th percentile did not differ (27.9% vs 27.4%, P = .929), nor did the rate of birthweight <10th percentile (48.8% vs 50.2%, P = .815). We had 80% power with an alpha error of 5% to show a difference in the likelihood of IUGR <10th percentile from 50% to 66% and a difference in the likelihood of IUGR <5th percentile from 27% to 42% in patients without and with preeclampsia. CONCLUSION: In patients with twin pregnancy, there is no correlation between preeclampsia and IUGR. This suggests that in twin pregnancies, as opposed to singleton pregnancies, the pathophysiology may differ between these 2 common conditions.

Screening approach for gestational diabetes in twin pregnancies.

OBJECTIVE: The objective of this study was to evaluate the ideal cutoff for the glucose challenge test (GCT) in twin pregnancies undergoing screening for gestational diabetes mellitus (GDM). STUDY DESIGN: A historical cohort of patients with twin pregnancies were identified from 1 maternal-fetal medicine practice from 2005 through 2013. All patients were administered a 1-hour, 50-g GCT between 24-28 weeks' gestation. All patients with a GCT of ≥130 mg/dL underwent a 3-hour, 100-g oral glucose tolerance test. The diagnosis of GDM was made if 2 of the 4 values on the oral glucose tolerance test were abnormal (Carpenter and Coustan). The testing characteristics of the GCT for diagnosis of GDM were evaluated using 3 selected cutoffs: ≥130, ≥135, and ≥140 mg/dL. We excluded all patients diagnosed with GDM <24 weeks. RESULTS: In all, 475 patients with twin pregnancies underwent a GCT between 24-28 weeks. The incidence of GDM was 6.5%. The positive screen rate using the 3 selected cutoffs were: ≥130 mg/dL, 34.7%; ≥135 mg/dL, 28.6%; and ≥140 mg/dL, 23.4%. A GCT cutoff of ≥135 mg/dL maintained 100% sensitivity, with a specificity of 76.4%. Using this cutoff, the positive predictive value was 22.8% and the negative predictive value was 100%. Compared to a cutoff of ≥130 mg/dL, a cutoff of ≥135 mg/dL resulted in 6.1% less patients testing positive while maintaining the same 100% sensitivity. CONCLUSION: In twin pregnancies, the optimal 1-hour, 50-g GCT screening cutoff appears to be ≥135 mg/dL.

Natural history of vasa previa across gestation using a screening protocol.

OBJECTIVES: The purpose of this study was to estimate the prevalence and persistence rate of vasa previa in at-risk pregnancies using a standardized screening protocol. METHODS: We conducted a descriptive study of patients with a diagnosis of vasa previa from a single ultrasound unit between June 2005 and June 2012. Vasa previa was defined as a fetal vessel within 2 cm of the internal cervical os on transvaginal sonography. Screening for vasa previa using transvaginal sonography with color flow mapping was performed routinely in the following situations: resolved placenta previa, prior pregnancy with vasa previa, velamentous insertion of the cord in the lower uterine segment, placenta succenturiata in the lower uterine segment, and twin gestations. RESULTS: A total of 27,573 patients were referred to our unit for fetal anatomic surveys over the study period. Thirty-one cases of vasa previa were identified, for an incidence of 1.1 per 1000 pregnancies. Twenty-nine cases had full records available for analysis. Five patients (17.2%) had migration and resolution of the vasa previa. When the diagnosis was made during the second trimester (<26 weeks), there was a 23.8% resolution rate (5 of 21); when the diagnosis was made in the third trimester, none resolved (0 of 8 cases). Of the 24 pregnancies (5 twin gestations and 19 singleton gestations) with persistent vasa previa, there was 100% perinatal survival and a median length of gestation of 35 weeks (range, 27 weeks 5 days-36 weeks 5 days). No known missed cases were identified over the study period. CONCLUSIONS: The use of standardized screening for vasa previa based on focused criteria was found to be effective in diagnosing vasa previa, with a 100% survival rate. Vasa previa diagnosed during the second trimester resolves in approximately 25% of cases.