Neonatal complications associated with use of fetal scalp electrode: a retrospective study.

OBJECTIVES: To estimate the incidence and risk of complications associated with a fetal scalp electrode and to determine whether its application in the setting of operative vaginal delivery was associated with increased neonatal morbidity. DESIGN: Retrospective cohort study. SETTING: Twelve clinical centers with 19 hospitals across nine American Congress of Obstetricians and Gynecologists US districts. POPULATION: Women in the USA. METHODS: We evaluated 171 698 women with singleton deliveries ≥ 23 weeks of gestation in a secondary analysis of the Consortium on Safe Labor study between 2002 and 2008, after excluding conditions that precluded fetal scalp electrode application such as prelabour caesarean delivery. Secondary analysis limited to operative vaginal deliveries ≥ 34 weeks of gestation was also performed. MAIN OUTCOME MEASURES: Incidences and adjusted odds ratios with 95% confidence intervals of neonatal complications were calculated, controlling for maternal characteristics, delivery mode and pregnancy complications. RESULTS: Fetal scalp electrode was used in 37 492 (22%) of deliveries. In non-operative vaginal delivery, fetal scalp electrode was associated with increased risk of injury to scalp due to birth trauma (1.2% versus 0.9%; adjusted odds ratios 1.62; 95% confidence intervals 1.41-1.86) and cephalohaematoma (1.0% versus 0.9%; adjusted odds ratios 1.57; 95% confidence intervals 1.36-1.83). Neonatal complications were not significantly different comparing fetal scalp electrode with vacuum-assisted vaginal delivery and vacuum-assisted vaginal delivery alone or comparing fetal scalp electrode with forceps-assisted vaginal delivery and forceps-assisted vaginal delivery alone. CONCLUSIONS: We found increased neonatal morbidity with fetal scalp electrode though the absolute risk was very low. It is possible that these findings reflect an underlying indication for its use. Our findings support the use of fetal scalp electrodes when clinically indicated. TWEETABLE ABSTRACT: Neonatal risks associated with fetal scalp electrode use were low (injury to scalp 1.2% and cephalohaematoma 1.0%).

Does increasing body mass index affect cerclage efficacy?

OBJECTIVE: To study the relationship between body mass index (BMI) and gestational age (GA) at delivery in patients with cervical insufficiency (CI) undergoing cerclage. STUDY DESIGN: We accessed a database of patients with singleton gestations undergoing cerclage (N=168) for a well-characterized history of CI, shortened cervix <2.5 cm with a history of prior preterm delivery or prolapse of membranes through the external os. Univariate and multivariate logistic regression analysis were performed to compare obstetrical outcomes between obese and normal-weight patients. RESULT: Prior preterm delivery <35 weeks in obese vs normal-weight patients was significantly higher (44% vs 9%), odds ratio=6.9 (95% CI: 2.5, 18.5), with lower mean GA at delivery (32.6±7.0 vs 37.2±3.4 weeks, P<0.001). After controlling for confounders, BMI remained significantly predictive of prematurity (coefficient: -0.12, adjusted R (2)=0.24), such that every additional 1 unit of BMI was associated with a 1-day reduction in GA at delivery (P=0.03). CONCLUSION: An inverse correlation exists between BMI and GA at delivery in patients with CI receiving cerclage. The findings are unexpected given the protective effect of obesity on spontaneous preterm delivery.

Patient decisions regarding prenatal aneuploid fluorescence in situ hybridization results.

OBJECTIVE: To determine an appropriate risk cut-off to offer prenatal aneuploid FISH, and if FISH results affect patient decisions regarding pregnancy management. METHOD: Retrospective evaluation of 707 patients presenting for diagnostic prenatal testing. Studied parameters included gestational age, indication for testing, aneuploid risk, procedure performed, FISH (whether offered, requested, and/or performed), result turn-around time, karyotype results, decision after obtaining results, and the timing of that decision. Patients who were offered FISH were compared to those not offered FISH (student T-test). RESULTS: Twenty-five clinically significant abnormalities were detected by karyotype and/or FISH analysis. Thirteen out of 17 patients electing pregnancy interruption had FISH performed. There were no differences between the group that interrupted following FISH (n=7) and the group that interrupted following final karyotype results (n=6). Turn-around times for those abnormal samples with FISH testing was significantly shorter than for those without FISH testing (p=0.02). Risk thresholds of >or=0.5%, >or=1%, >or=2%, or >or=3%, would detect 92%, 84%, 48%, and 32% of the clinically significant anomalies with 663, 317, 118, and 66 FISH analyses performed, respectively. CONCLUSION: Acting on FISH results alone afforded a significantly shorter interval between test and pregnancy interruption. A risk cut-off >or=1% appears to optimize the detection rate and the yield of abnormal results.

Predictive value of transvaginal cervical length in triplet pregnancies for spontaneous preterm delivery at < or = 32 weeks.

OBJECTIVE: To establish whether cervical length is a predictor of spontaneous preterm delivery at < or = 32 weeks in triplet pregnancies. METHODS: This was a case-control study of all triplet pregnancies followed with more than three sonographic assessments of cervical length at 4-week intervals from 1995 to 2000. Cervical length in women delivered spontaneously at < or = 32 weeks (cases) was compared with that of the remaining women (controls). Statistical analysis included Fisher's exact test, chi2 test, one-way analysis of variance, logistic regression and receiver operating characteristic (ROC) curve to determine optimal cervical length thresholds for spontaneous preterm delivery at < or = 32 weeks. RESULTS: Of the 58 women included in the study, 17 (29%) delivered spontaneously at < or = 32 weeks. The preterm delivery group had similar demographic and obstetric variables, but a higher rate of cerclage placement (65% vs 17%, p < 0.001) than controls. Mean +/- standard deviation cervical length was significantly shorter among cases than controls at 16-20.0 weeks (3.0 +/- 1.2 vs. 3.9 +/- 0.8 cm, p = 0.01), but not at 20.1-24.0 weeks (3.5 +/- 1.1 vs. 3.8 +/- 1.0 cm, p = 0.76). Logistic regression analysis determined that cervical length at 16-20 weeks had an odds ratio of 0.43 (95% CI = 0.23, 0.80) for the prediction of spontaneous preterm delivery at < or = 32 weeks. ROC curve analysis identified a cervical length of < or = 2.6 cm as the optimal threshold for the prediction of spontaneous preterm delivery at < or = 32 weeks (sensitivity 41%, specificity 92%). CONCLUSIONS: In a population of triplet gestations with a 29% rate of preterm delivery, cervical length at 16-20.0 weeks, but not at 20.1-24.0 weeks, was inversely correlated with the probability of preterm delivery at < or = 32 weeks.

Threshold-level repetitive transcranial electrical stimulation for intraoperative monitoring of central motor conduction.

OBJECT: The authors conducted a study to evaluate repetitive transcranial electrical stimulation (TES) to assess spinal cord motor tract function in individuals undergoing spine surgery, with emphasis on safety and efficacy. METHODS: Somatosensory evoked potentials (SSEPs) were elicited using standard technique. Muscle electromyographic values were measured in response to a three- or four-pulse train of stimulation delivered to the motor cortex via subdermal electrodes. They also evaluated whether changes in the minimum stimulus intensity (that is, threshold level) needed to elicit a response from a given muscle predict motor status immediately postoperatively, as well as whether changes in SSEP response amplitude and latency predict sensory status immediately postoperatively. Anesthesia was routinely induced with intravenous propofol and remifentanil, supplemented with inhaled nitrous oxide. Use of neuromuscular block was avoided after intubation. Satisfactory monitoring of muscle response to threshold-level repetitive TES was achieved in all but nine of the 194 patients studied. In contrast, cortical SSEP responses could not be elicited in 42 of 194 individuals. In cases in which responses were present, TES-based evoked responses proved to be extremely accurate for predicting postoperative motor status. Somatosensory evoked potential monitoring was nearly as accurate for predicting postoperative sensory status. There were frequent instances of postoperative motor or sensory deficit that were not predicted by SSEP- and TES-based monitoring, respectively. There were no adverse events attributable to TES-based monitoring, although since this study ended we have had a single adverse event attributable to threshold-level repetitive TES. CONCLUSIONS: Intraoperative threshold-level repetitive TES-based monitoring of central motor conduction has proven to be a simple, safe, and highly accurate technique for the prevention or minimization of inadvertent motor deficit during surgery involving the spine or spinal cord.

Electromyography during stereotactic pallidotomy for Parkinson's disease.

In stereotactic pallidotomy for Parkinson's disease, care must be taken to avoid internal capsule injury while maximizing improvement of rigidity and tremor. In 21 patients, intraoperative electromyography (EMG) was used to assess stimulation thresholds required for capsular responses and to monitor muscle tone and tremor. Surface EMG electrodes were placed on the face and multiple muscle groups of the extremities. The stimulation and lesion electrode was introduced via MRI-guided stereotaxis toward a point 2-3 mm anterior to the midcommissural point, 5-6 mm inferior to the AC-PC plane, and 21-22 mm lateral to the midline. Exact targets were modified according to MRI-visualized anatomy. With stimulation at 5 and 50 Hz, thresholds for detection of EMG responses were usually seen at 4-5 mA. EMG responses were consistently seen prior to visual observation of muscle activity. Timing of EMG response relative to stimulus aided in differentiating stimulus-related movement from spontaneous tremor. Resting spontaneous EMG activity was seen to decrease as rigidity was improved by incremental lesion production. EMG activity related to tremor was recorded; tremor decrease by lesion production was documented by EMG recording. Patient cooperation with physiologic testing during stimulation and lesion production may become limited. Intraoperative EMG monitoring provides an adjunct to improve reliability of assessment of capsular stimulation and rigidity while providing documentation of lesion impact on rigidity and tremor.

Early MRI findings in high grade glioma.

Magnetic resonance imaging (MRI) is more sensitive than computerized tomography in the detection of many intracerebral lesions; however, the significance of some MRI findings may be unclear. Over four years, nine patients, aged 40-79 years, have been encountered whose initial MRI scans were negative or had minimal abnormalities and soon thereafter had high grade glioma. Initial MRI was performed in eight patients for new-onset seizures and one patient for a focal deficit. MRI was negative in four of the patients and mildly abnormal in five of the patients (small areas of increased T2 and/or minimal enhancement). The initial diagnoses usually included inconclusive differentials of stroke and infection with neoplasm less frequently considered. Radiographic progression leading to the diagnosis of high grade glioma became evident on repeat MRI in 1-8 months with six patients showing progression within three months. All patients underwent surgery and had histologic diagnosis of glioma. Although MRI is quite sensitive, four of the initial scans were negative with reasonable quality studies. Conversely, in five of the initial scans, the tumors were detected when so small that the radiographic findings were not typically diagnostic. Glioma must be considered as a possible cause of initial seizures or new neurologic deficits in adults with normal or minimally abnormal MRI. In this group, seizures were the overwhelming hallmark of presentation. In such a clinical situation, close follow-up with short interval repeat MRI should be performed.

Association of sex of the fetus in isolated fetal choroid plexus cysts.

We sought to determine if an association exists between sex of the fetus and the finding of isolated fetal choroid plexus cysts. Of 131 fetuses, 62 were male (47.3%) and 69 were female (52.7%). No statistically significant differences were found in the maternal demographic parameters studied (age, race, gravidity, parity, sonogram timing) or descriptive cyst information obtained (location, number, dimensions, resolution), although bilaterality was more common in male fetuses. The determination that isolated choroid plexus cysts are seen equally frequently in male and female fetuses adds to basic information about such a common sonographic finding.

Spinal metastases of malignant intracranial meningioma.

BACKGROUND: Spinal metastasis of intracranial meningiomas has rarely been reported. Three out of ten previously reported cases of malignant meningioma metastasizing to the spine had undergone surgical debulking with no neurological improvement. The authors retrospectively reviewed the treatment course of three patients with malignant meningioma metastasizing to the spine who underwent early magnetic resonance imaging (MRI) and radiotherapy without surgical debulking. CASE DESCRIPTION: Three patients with intracranial malignant meningiomas underwent multiple resections of intracranial lesions, and developed spinal intradural metastases an average of 64 months (range, 27-102 months) from their initial presentation. All three patients had at least two operations for recurrent intracranial tumors. All had localized back pain with motor weakness, and MRI scans demonstrated spinal involvement. No surgical exploration was performed for the spinal lesions; rather, all patients received steroids and radiotherapy for the spinal lesions. All three patients improved neurologically after the steroid and radiation treatments, and went on to survive from 3 to 18 months. CONCLUSION: Early MRI should be performed in patients with spinal symptoms and signs after the treatment of intracranial meningiomas. Radiotherapy is an effective palliative treatment for spinal metastases.

The vanishing twin: a review.

This article reviews the scientific literature discussing the vanishing twin phenomenon. Information pertaining to frequency, aetiology, and potential complications, as well as the impact of sonographic technology on our growing understanding of the events in early multiple pregnancy is provided.

Fetal bradycardia secondary to magnesium sulfate therapy for preterm labor. A case report.

BACKGROUND: Alterations in fetal heart rate variability and baseline may be seen with maternal administration of magnesium sulfate. In this case, a dose-related decrease in the baseline fetal heart rate was observed in association with magnesium sulfate administration. CASE: A primiparous woman was given parenteral magnesium sulfate for preterm labor. After tocolytic administration, the fetal heart rate baseline decreased to 110 beats per minute (bpm) from its initial rate of 140 bpm, although good variability was maintained. Increasing the dosage was accompanied by a further drop in the baseline heart rate, to 100 bpm. Fetal echocardiography was normal except for sinus bradycardia. Stopping magnesium sulfate administration was accompanied by a return to the pretherapy baseline heart rate. The pregnancy progressed without any further complications, and a healthy infant was delivered three weeks later. CONCLUSION: Maternal administration of magnesium sulfate may be associated with a profound decrease in the baseline fetal heart rate, resulting in fetal sinus bradycardia.

Diagnosing gestational diabetes mellitus: use of a glucose screen without administering the glucose tolerance test.

OBJECTIVE: To determine if a 1-hour glucose screen value could be identified, above which gestational diabetes mellitus could be diagnosed without the 3-hour oral glucose tolerance test (GTT). METHODS: Demographic, historic, obstetric, and neonatal data from 514 singleton pregnancies with glucose screen values at least 140 mg/dL followed by a GTT were reviewed (312 patients with normal GTTs and 202 with gestational diabetes mellitus). Statistical analyses used chi2, Fisher exact, Student t, and Mann-Whitney tests. After determining the optimal glucose screen cutoff point using receiver operating characteristic curve analyses, patients were regrouped according to this value and analyzed further. RESULTS: The optimal cutoff point for the upper limit of the glucose screen was determined to be 186 mg/dL (95.9% specificity, 98.2% negative predictive value, 36.1% sensitivity, and 19.6% positive predictive value). Comparison of patients with elevated screens and normal GTTs versus those with gestational diabetes revealed significant differences only regarding a history of gestational diabetes mellitus and neonatal hypoglycemia in the studied pregnancy. Those with screens greater than 185 mg/dL behaved like diabetic patients and, when compared with subjects with screens of 140-185 mg/dL, also had a significantly greater proportion of large for gestational age infants. CONCLUSION: Patients with 1-hour glucose screens greater than 185 mg/dL have a high probability of gestational diabetes mellitus and the diagnosis can be made without the GTT. Using this approach could allow prompt initiation of therapy without the inconvenience and discomfort of the GTT.

The fetus with gastroschisis: impact of route of delivery and prenatal ultrasonography.

OBJECTIVES: Our purpose was (1) to assess the influence of delivery route on neonatal outcome in fetuses with gastroschisis and (2) to correlate ultrasonographic appearance of fetal bowel with immediate postnatal outcome. STUDY DESIGN: Forty-seven cases (1986 to 1994) were reviewed; three abortions and two stillbirths were excluded. Ultrasonographic appearance of fetal bowel (small bowel dilatation > 10 mm) was evaluated in 27 cases. RESULTS: Twenty-six infants (61.9%) were delivered vaginally and 16 (38.1%) by cesarean section (11 elective, 5 in labor). Delivery route was not significantly associated with indicators of neonatal outcome (rate of primary closure, postoperative complications, days of parenteral nutrition, days to oral feeding, hospital days, or mortality). When ultrasonographic appearance of fetal bowel was correlated with outcome, fetuses with prenatally dilated bowel had significantly more bowel edema at birth (p=0.038), longer operative time (p=0.013), and higher overall rate of postoperative complications (p=0.037). CONCLUSIONS: (1) Elective cesarean delivery does not improve neonatal outcome in infants with gastroschisis. (2) Abnormal ultrasonographic appearance of fetal bowel is associated with a more difficult repair and a higher overall incidence of postoperative complications.

Arteriovenous malformation associated with pleomorphic xanthoastrocytoma.

A case of a left temporo-occipital arteriovenous malformation associated with a pleomorphic xanthoastrocytoma is described. The patient had the vascular lesion with a stable right hemiparesis for many years prior to his recent clinical deterioration. Correlation is made with nine previously reported cases of angiogliomas. With the close proximity and temporal correlation of the two components of this lesion, as well as pathological evidence, the authors propose that angioglioma may be the product of reactive glial proliferation and transformation secondary to a pre-existing vascular malformation and hemorrhage.

Retrospective epidemiologic analysis of patients diagnosed with intracranial meningioma from 1977 to 1990 at the Jackson Memorial Hospital, Sylvester Comprehensive Cancer Center: the Jackson Memorial Hospital Tumor Registry experience.

A descriptive analysis was performed of the Tumor Registry data for intracranial meningioma by the Jackson Memorial Hospital, University of Miami School of Medicine Tumor Registry. A total of 108 cases of intracranial meningioma was collected and reviewed. Overall survival for 2, 5, and 10 years was 82, 72, and 60%, respectively. There was no difference in survival for males and females at 5 years, nor any difference in survival for race or ethnicity. There was a trend for improved survival for the young age group (18-55 years).

Stereotactic dose computation and plan optimization using the convolution theorem. I. Dose computation.

With Leksell Gamma Knife stereotactic radiosurgery, the dose distribution delivered by a specific helmet can be assumed to remain as a fixed-dose distribution when the shot is moved to different locations within the predefined dose calculation matrix. The convolution theorem may be implemented to take advantage of this fact for fast dose computation and plan construction. Using this technique, the shot spatial arrangement is formulated as a convolution kernel, which is theoretically a three-dimensional multi-delta function. The dose distribution is computed by the convolution of this single-shot dose distribution with the shot convolution kernel. To determine the shot arrangement, an ideal dose distribution is generated based upon the target structure. Deconvolution is then applied to find the convolution kernel which best fits the proposed ideal dose distribution. The primary task of this presentation is to focus on and describe in detail the dose computation using the convolution theorem.