Fetal head prior to delivery: precise measurement, using a mathematically extrapolated frontooccipital diameter.

PURPOSE: To find a method that could improve the accuracy of fHC evaluation at term. MATERIAL AND METHODS: This retrospective cohort study was based on data from the University Hospital of Zürich (USZ). Study population included singleton fetuses and newborns at term between 2015 and 2017. Fetal biometry was performed within 1 week prior to delivery. Study data consisted of two cohorts with 200 ultrasound measurements each: 200 performed by an expert, 200 by residents. fHC were compared with the newborn's head circumference (nHC). fHC was estimated using two methods: (1) fHC based on sonographically estimated frontooccipital diameter (FOD) and biparietal diameter (BPD). (2) Expected FOD was calculated as a fixed mean FOD/BPD relation, derived from biometry standards as the 50th percentile. If BPD was < 99 mm, FOD was calculated according to the formula BPD × 1.268557, If BPD was ≥ 99 mm, FOD was calculated according to the formula BPD × 1.20641443. RESULTS: fHC was underestimated compared with nHC in the expert group: percentage error (PE = - 3.68%, SD = 2.79), as well as in the group of residents (PE = - 3.78%, SD = 3.20) using method 1. fHC measurement was significantly more accurate using method 2. In the expert group PE = - 1.17%, SD = 3.08, in the group of residents PE = - 0.95%, SD = 3.33. Bland-Altman analysis showed limits of agreement (LOA) between - 2.41338 and 0.5537828 cm for fHC. CONCLUSIONS: Accuracy of fHC estimation could be improved by extrapolation of FOD when real-time FOD cannot be measured.

Two-dimensional critical systems with mixed boundary conditions: Exact Ising results from conformal invariance and boundary-operator expansions.

With conformal-invariance methods, Burkhardt, Guim, and Xue studied the critical Ising model, defined on the upper half plane y>0 with different boundary conditions a and b on the negative and positive x axes. For ab=-+ and f+, they determined the one- and two-point averages of the spin σ and energy ε. Here +,-, and f stand for spin-up, spin-down, and free-spin boundaries, respectively. The case +-+-+⋯, where the boundary condition switches between + and - at arbitrary points, ζ_{1},ζ_{2},⋯ on the x axis was also analyzed. In the first half of this paper a similar study is carried out for the alternating boundary condition +f+f+⋯ and the case -f+ of three different boundary conditions. Exact results for the one- and two-point averages of σ,ε, and the stress tensor T are derived with conformal-invariance methods. From the results for 〈T〉, the critical Casimir interaction with the boundary of a wedge-shaped inclusion is derived for mixed boundary conditions. In the second half of the paper, arbitrary two-dimensional critical systems with mixed boundary conditions are analyzed with boundary-operator expansions. Two distinct types of expansions-away from switching points of the boundary condition and at switching points-are considered. Using the expansions, we express the asymptotic behavior of two-point averages near boundaries in terms of one-point averages. We also consider the strip geometry with mixed boundary conditions and derive the distant-wall corrections to one-point averages near one edge due to the other edge. Finally we confirm the consistency of the predictions obtained with conformal-invariance methods and with boundary-operator expansions, in the the first and second halves of the paper.

Effect of maternal smoking on stress physiology in healthy neonates.

OBJECTIVE: To assess the impact of maternal smoking during pregnancy (MSDP) on the neonatal hypothalamic-pituitary-adrenal axis. STUDY DESIGN: In a prospective observational study, salivary cortisol and cortisone levels were measured at the fourth day of life during resting conditions and in response to a pain-induced stress event in healthy neonates whose mothers smoked cigarettes during each stage of pregnancy and compared with controls. RESULTS: Neonates in the control group (n=70) exhibited a physiologic stress response with a significant increase in cortisol (1.3 to 2.1 ng ml-1; P<0.05) and cortisone (11.8 to 17.8 ng ml-1; P<0.05) from baseline levels, whereas in neonates from mothers who smoked (n=33), cortisol (0.9 to 0.8 ng ml-1; P=0.77) and cortisone (11.5 to 13.0; P=0.19) stress response was not significantly different from baseline levels. A two-way analysis of variance confirmed these findings in both groups. CONCLUSIONS: Healthy neonates whose mothers smoked during pregnancy show a blunted stress response on the fourth day of life. Thus, MSDP leads to a dysregulation of the HPA axis with continued effects in neonatal life. This might explain long-term consequences of MSDP such as overweight, diabetes mellitus and modification of blood pressure control mechanisms in adult life.

Outcome and risk factors of cesarean delivery with and without cesarean myomectomy in women with uterine myomatas.

AIM: To evaluate the outcome of a cesarean myomectomy (CM) versus a cesarean delivery (CD) alone in women with uterine myomas and the risk factors for adverse outcomes. METHODS: A retrospective cohort study of all women undergoing CDs with uterine leiomyomatas and singleton pregnancies was performed. Patients with known risk factors for hemorrhage were excluded. Measured adverse outcome parameters included estimated blood loss, drop in hemoglobin levels (pre/postoperatively), operation time, and the use of additional uterotonics. Outcome parameters of women with CM were compared to women with CD alone. Possible risk factors for adverse outcomes were analyzed in a multivariate regression analysis. Evaluated risk factors for CM were according to localization and type of myomatas, the myoma size, BMI ≥30 kg/m2, age ≥40 years, fetal weight ≥4 kg, repeat CD, and unplanned CD in the first stage of labor. The influence of localization and myoma type were further analyzed in a subgroup analysis. RESULTS: Of the 162 women with uterine myomatas during CD, 48 underwent CM and were analyzed. Overall, CM was not associated with adverse outcomes. Independent of a concomitant myomectomy, a large myoma size of ≥5 cm was associated with an increased blood loss of ≥500 ml (adj. OR 2.7 CI 95 % 1.2-6.2, p = 0.02), and women ≥40 years of age had a significant postoperative drop in hemoglobin (adj. OR 2.4 CI 95 % 1.0-5.4, p = 0.04). In the univariate subgroup analysis, CM of multiple myomatas was associated with an increased blood loss and an increased operation time compared to women with multiple myomatas and CD alone. Prolonged operation times were also observed in women with pedunculated and subserosal myomatas with concomitant myomectomy. There were no cases of hysterectomy or blood transfusions. CONCLUSION: CM performed by an experienced obstetrician can be safe in selected patients who are without additional preexisting risk factors. Risk factors that are associated with increased blood loss in women with uterine leiomyomatas include a larger size of the leiomyoma (≥5 cm) and a maternal age of ≥40 years.

Casimir interaction of rodlike particles in a two-dimensional critical system.

We consider the fluctuation-induced interaction of two thin, rodlike particles, or "needles," immersed in a two-dimensional critical fluid of Ising symmetry right at the critical point. Conformally mapping the plane containing the needles onto a simpler geometry in which the stress tensor is known, we analyze the force and torque between needles of arbitrary length, separation, and orientation. For infinite and semi-infinite needles we utilize the mapping of the plane bounded by the needles onto the half plane, and for two needles of finite length we use the mapping onto an annulus. For semi-infinite and infinite needles the force is expressed in terms of elementary functions, and we also obtain analytical results for the force and torque between needles of finite length with separation much greater than their length. Evaluating formulas in our approach numerically for several needle geometries and surface universality classes, we study the full crossover from small to large values of the separation to length ratio. In these two limits the numerical results agree with results for infinitely long needles and with predictions of the small-particle operator expansion, respectively.

Health-related Quality of Life in Patients After Treatment of Cushing's Disease.

BACKGROUND: Patients suffering from Cushing's disease are known to be restricted due to a wide range of symptoms. Despite biochemical cure, symptoms might last life-long. These include - among well-known somatic symptoms - several neuropsychiatric symptoms that cannot be as easily tested, but lead to a serious negative impact on quality of life. We aimed to evaluate what factors diminish the self-perceived quality of life the most using 3 questionnaires visualizing those impairments. Furthermore we investigated whether there would be differences in quality of life between patients still being affected by the disease and those that are already in remission. PATIENTS AND METHODS: We reviewed patient charts treated between April 2008 and June 2012 for Cushing's disease and sent 3 questionnaires to the patients for evaluation. For this purpose we used the SF-36, the BDI and the Tuebingen CD-25. 54 patients complied with our request and returned the completed questionnaires. The average time after surgery was 36 months. RESULTS: In all 8 dimensions of the SF-36 significant differences between the patient collective and the expected age- and gender-specific scores could be observed and thus a detectable impairment in quality of life. The BDI revealed that every other patient suffering from Cushing's disease presented depressive symptoms, partially with clinical relevance. In all 6 dimensions of the Tuebingen CD-25 there were notable restrictions in patients. Those restrictions particularly concerned bodily restrictions and cognitive performance. The self-perceived quality of life of active patients was - although not statistically significant - in almost all measured fields worse than the test results of patients in remission after TSS. CONCLUSION: Former and active Cushing's disease patients suffer from a wide range of neuropsychiatric symptoms. Those symptoms might dominate the clinical picture and lead to a serious impairment in quality of life as well as extend periods of suffering and might persist even years after being found healthy. Therefore it is important to evaluate quality of life as an independent factor in every patient being affected by Cushing's disease and to include a holistic view in their therapy. Concomitant therapeutic measures should be accessible at any time for Cushing's disease patients as the normalization of pathologically increased laboratory values doesn't obligatory lead to an improvement of the patients subjectively felt well-being.

Surgical management of pituitary metastases.

BACKGROUND: Pituitary metastases are rare and commonly described in case reports or small case series. Due to its rarity this entity is not subject to standardized treatment guidelines, there is debate about typical initial symptoms that may lead to finding the correct diagnosis and information about the clinical course is also sparse. METHODS: We have conducted a retrospective analysis of patients with pituitary metastases who were surgically treated via a transsphenoidal procedure at our institution between 2006 and 2014. Underlying primary disease, clinical and surgical course as well as adjuvant radiotherapy and follow-up data are presented. RESULTS: 14 patients met the inclusion criteria (8 female, 6 male). Mean age was 61.5 years. Most patients became symptomatic with visual symptoms--both visual deterioration and/or diplopia (n = 13)--and anterior lobe insufficiency (n = 8). Surprisingly diabetes insipidus was only seen in three patients. All patients underwent transsphenoidal surgery initially, four patients had to undergo surgery for residual tumor or recurrence, two of them via a transcranial route. Breast cancer was the most common entity (n = 6), followed by prostate cancer (n = 3), nsclc (n = 2) and melanoma, thyroid cancer and renal cancer in one case each. Postoperative MRI showed gross total resection in four cases and residual disease in eight cases (subtotal resection, partial resection and biopsy), two patients files were incomplete regarding MRI-results. All patients underwent adjuvant radiotherapy. Survival after the initial diagnosis of cancer was 36 and 16 months after diagnosis of pituitary metastases. CONCLUSION: Our results indicate that transsphenoidal surgery is a safe method to resect pituitary metastases and that the extend of resection does not have an influence on survival time. Our results also indicate that diabetes insipidus may not be the most common initial symptom of pituitary metastases and lack thereof should not lead to making a wrong diagnosis and delaying appropriate therapy.

Donor vigilance data of a blood transfusion service: A multicenter analysis.

BACKGROUND: Donor vigilance is an important part of the quality management system of blood transfusion services. The evaluation of donor side effects helps to improve the donation process and donor compliance. The aim of the present study was to evaluate donor vigilance data in whole blood and plasmapheresis donors of a blood donor service. MATERIALS AND METHODS: Donors fulfilling current national and European eligibility criteria underwent whole blood and plasmapheresis donation (PCS and MCS+ (Haemonetics, Braintree, USA), A 200 (Fenwal, Round Lake, USA). Whole blood was collected at fixed and mobile sites while plasmaphereses were performed at 8 plasma centers. From 2011 to 2013 donor information was provided for gender, age, body weight, height, first and repeat donation. Donors were monitored for venipuncture and circulatory associated side effects. RESULTS: The total incidences of adverse events were 5004 (0.56%) in repeat donors and 2111 (2.78%) in first time donors for whole blood donation and 3323 (1.01%) and 514 (7.96%) for plasmaphereses, respectively. Circulatory associated events were 2679 (0.30%) for whole blood donation and 1624 (0.49%) for plasmaphereses. CONCLUSION: Our donor vigilance data of a blood transfusion service show that whole blood and plasmapheresis are safe with low incidences of adverse events. Repeat donation and age are predictors for low rates of adverse events. On the other hand, first time donation and female gender were associated with higher incidences of adverse events.

A pitfall in diagnosing Cushing's disease: ectopic ACTH-producing pituitary adenoma in the sphenoid sinus.

PURPOSE: To show a rare case of Cushing's disease and possible cause of failed transsphenoidal surgery. METHOD: We report on a 50-year-old woman suffering from ACTH-dependent Cushing's syndrome. Endocrinological work-up including low-dose/high-dose dexamethasone test (Liddle-test) and CRH test were clearly compatible with pituitary origin. Although an MRI showed no pituitary tumor, CRH-stimulated petrosal sinus sampling revealed a significant central-peripheral gradient in ACTH concentrations, rendering Cushing's disease very likely. The patient underwent transsphenoidal surgery with negative exploration of the pituitary gland. After intraoperative re-evaluation of the preoperative MRI, a "polyp" at the bottom of the sphenoid sinus was identified. The intraoperative microscopic aspect as well as instantaneous sections and cytology of a biopsy confirmed an adenoma, which was then removed. Histological analysis demonstrated an ACTH-producing pituitary adenoma adjacent to respiratory mucous membrane consisting of ciliated epithelium with submucous connective tissue. Postoperatively, ACTH concentrations were decreased and intermittent hydrocortisone substitution treatment was initiated. At the 3-month follow up, Cushing's stigmata were found to be alleviated and the hydrocortisone dosage could be reduced. CONCLUSION: Ectopic pituitary adenoma tissue causing Cushing's disease is extremely rare but a potential cause for surgical failure or re-evaluation.

Off-label antiobesity treatment in patients without diabetes with GLP-1 agonists in clinical practice.

The aim of the work was to investigate whether continuation of treatment, side effects, and effect on weight loss of GLP-1 agonists in obese patients without diabetes are equally promising in daily clinical-practice-settings compared to controlled clinical trials. Obese patients without diabetes of our interdisciplinary obesity centre were treated off-label with GLP-1-agonists for different time periods. Application was started with low-dose and increased if side effects were tolerable. Monthly costs were € 125 for daily applications of 1.2 mg liraglutide or 10 µg exenatide twice daily. Data were obtained by telephone interviews about baseline characteristics, weight loss, sensation of satiation, duration of therapy, side effects, and reasons for discontinuation. Of 43 included cases (5 males, mean age 43±11 years, mean weight 107±24 kg, mean excess weight 35±21 kg) 7 were treated with exenatide and 36 with liraglutide. Excess weight loss in linear regression models was 6.7% per month (p <0.05) under control of age, sex, initial weight, and type of GLP-1 analogue treatment and did not significantly differ between liraglutide and exenatide. Overall, 58% of patients reported side effects mostly concerning the gastrointestinal tract. Surprisingly no patient reported vomiting. One patient developed a severe pancreatitis. At time of telephone interview only 30.2% were continuing treatment. Mean treatment duration was 2.98±2.71 months. Common reasons for discontinuation of treatment were no/little effect on weight loss (27.9%), intolerable side effects (20.9%), or financial reasons (14%). GLP-1 agonist treatment in obese patients without diabetes also correlates with significant weight loss in clinical practice. However, side effects and discontinuation of treatment are common. Therefore, long-term effect on weight loss might not be as promising as suggested by data from clinical trials.

Hyponatremia after trans-sphenoidal surgery.

Fluid and electrolyte imbalances are the most frequent complications following pituitary surgery. Among the several patterns of occurrence, hyponatremia can occur in an isolated fashion or as part of a bi- or triphasic pattern. The frequency of hyponatremia after trans-sphenoidal surgery is between 2% and 25%, according to the literature. However, these numbers are probably underestimating the real prevalence, since mild hyponatremia does not lead to symptoms and measurement of sodium level. No association has been described between entity of the pituitary tumor or tumor size and hyponatremia. Therefore no predictors exist to determine patients with a higher risk for electrolyte imbalances after surgery. However, since delayed hyponatremia occurs mainly around the 8-10th day after surgery, routine measurement of sodium should be recommended on the day of hospital dismission. In case of a symptomatic hyponatremia, insufficiency of the corticotrophe pituitary function as the leading differential diagnosis needs to be ruled out. If the patient is euvoleme, pretest probability of syndrome of inadequate antidiuretic hormone production (SIADH) is very high and therapy may be started according to this. In case of SIADH, therapeutic options include fluid restriction or vaptane therapy. Only in severe cases infusion of hypertonic saline is appropriate. Usually SIADH following pituitary surgery is a self-limiting condition and will cease within 2-5 days.

Evaluation of fetal anthropometric measures to predict the risk for shoulder dystocia.

OBJECTIVE: To evaluate the quality of anthropometric measures to improve the prediction of shoulder dystocia by combining different sonographic biometric parameters. METHODS: This was a retrospective cohort study of 12,794 vaginal deliveries with complete sonographic biometry data obtained within 7 days before delivery. Receiver-operating characteristics (ROC) curves of various combinations of the biometric parameters, namely, biparietal diameter (BPD), occipitofrontal diameter (OFD), head circumference, abdominal diameter (AD), abdominal circumference (AC) and femur length were analyzed. The influences of independent risk factors were calculated and their combination used in a predictive model. RESULTS: The incidence of shoulder dystocia was 1.14%. Different combinations of sonographic parameters showed comparable ROC curves without advantage for a particular combination. The difference between AD and BPD (AD - BPD) (area under the curve (AUC) = 0.704) revealed a significant increase in risk (odds ratio (OR) 7.6 (95% CI 4.2-13.9), sensitivity 8.2%, specificity 98.8%) at a suggested cut-off ≥ 2.6 cm. However, the positive predictive value (PPV) was low (7.5%). The AC as a single parameter (AUC = 0.732) with a cut-off ≥ 35 cm performed worse (OR 4.6 (95% CI 3.3-6.5), PPV 2.6%). BPD/OFD (a surrogate for fetal cranial shape) was not significantly different between those with and those without shoulder dystocia. The combination of estimated fetal weight, maternal diabetes, gender and AD - BPD provided a reasonable estimate of the individual risk. CONCLUSION: Sonographic fetal anthropometric measures appear not to be a useful tool to screen for the risk of shoulder dystocia due to a low PPV. However, AD - BPD appears to be a relevant risk factor. While risk stratification including different known risk factors may aid in counseling, shoulder dystocia cannot effectively be predicted.

DHEA(S)--a novel marker in Cushing's disease.

INTRODUCTION: Dehydroepiandrosterone sulfate (DHEA(S)) is a multi-functional steroid implicated in a broad range of biological effects, including obesity, diabetes, bone metabolism, neuroprotection, and anti-tumorigenesis. It has not yet undergone wider research in the context of Cushing's disease. The objective of this study was to determine if perioperative blood levels of DHEA(S) correlate with levels of ACTH and cortisol, and therefore may be useful as a new, additional marker for the early definition of cure in patients suffering from Cushing's disease. METHODS: Forty-two consecutive patients undergoing transsphenoidal surgery for Cushing's disease from September 2009 to September 2010 were perioperatively monitored for ACTH, cortisol, and DHEA(S). RESULTS: Pre-operative blood samples revealed ACTH levels of median 65 ng/l (range 11-1,183 ng/l, standard deviation 183.76), cortisol of median 257 µg/l (range 93-803 µg/l, standard deviation 140.88), and DHEA(S) of median 2.22 mg/l (range 0.44-7.79 mg/l, standard deviation 1.82) according to the pathology of Cushing's disease. Postoperative blood samples drawn over a 7-day time span showed a drop in median ACTH to just 14.5 % (median: 9 ng/l, range 2-44, standard deviation 12.75) of its median preoperative figure. Median cortisol levels were reduced to 6.9 % (median: 18 µg/l, range 10-190 µg/l, standard deviation 38.04) of their preoperative values and DHEA(S) levels decreased to 17 % (median: 0.38 mg/l, range 0.05-2.29, standard deviation 0.51). In persistent disease, no patient showed a drop in DHEA(S) below 38 % of its preoperative figures. CONCLUSIONS: DHEA(S) shows the potential to become an additional marker in the diagnosis and follow-up of patients. However, it needs to be examined further, including whether DHEA(S) may also be a useful predictor of recovery of the HPA-axis after successful surgery.

Continuous independent quality control for fetal nuchal translucency measurements provided by the cumulative summation technique.

PURPOSE: The cumulative summation technique (CUSUM) is an innovative method for the quality control of nuchal translucency (NT) measurements. CUSUM allows immediate corrective intervention as soon as an unacceptable tendency is noted. The aim of this study was to implement an objective and dynamic quality control method based on the CUSUM technique for prompt analysis of fetal NT measurement which would be compatible with different standards in routine clinical practice. The findings were compared to the standard NT quality control methods currently in use. MATERIALS AND METHODS: Three sets of fetal NT measurements performed by three experienced examiners (I, II and III) were selected for retrospective evaluation. One additional set of NT measurements performed by examiner IV was prospectively assessed to approve the practicability of the method. NT measurements were conducted according to the recommendations of Fetal Medical Foundation (FMF) Germany and London. NT values were converted to Z-scores. For quality and accuracy evaluation, data were fed into the Digisono CUSUM software to create double CUSUM charts of Z-scores. In addition, histograms were composed from the Z-scores of each set of measurements and plotted against a normal Gaussian distribution. RESULTS: Three different patterns of retrospective performance and one set of NT measurements that was evaluated prospectively are presented. The full alignment of Z-scores using CUSUM curves reflected exact periods of under- and overestimation of NT measurements. The CUSUM chart of the prospective data set reveals that prompt corrective intervention of poor performance resulted in reconstitution of optimal results and provided sufficient control. In contrast, histograms of NT Z-scores only showed a minor positive or negative shift as compared to the expected values on the basis of Gaussian distribution, but could not identify poor performance. CONCLUSION: Use of the CUSUM technique analysing the quality of sonographic NT measurements provides the possibility to prospectively observe the development of the examiner's skills, to maintain competence and to promptly define the time when inaccurate measurements start to occur.

[Does a combination of foetal biometry and maternal MRI pelvimetry decrease the frequency of secondary caesarean section?]. / Senkt die Kombination von fetaler Biometrie und MRT-Pelvimetrie die Rate an sekundären Sectiones?

OBJECTIVE: Cephalopelvic disproportion (CPD) is a frequent indication for secondary Caesarean section. The delivery simulation software Anapelvis was developed to predict a CPD on the basis of foetal ultrasound biometry and maternal pelvimetry data. The objective of this retrospective study was to analyse the predictive value of Anapelvis software in consideration of antenatal foetal biometry quality. PATIENTS AND METHODS: 162 pregnant women with suspected CPD who had undergone a magnetic resonance imaging pelvimetry were included in this study. The antenatal foetal biometry was carried out within a week before delivery. RESULTS: The positive predictive value (PPV) for arrest of delivery was 85.7% in the group of 79 pregnancies with planned vaginal delivery. Sensitivity was 56.3%, specificity 60.0% and negative predictive value (NPV) 24.3% accordingly. The highest accuracy [percent error (PE) -0.1%] of fetal weight estimation was found in the group where an arrest of delivery was predicted. The lowest accuracy (PE -4.4%) was detected in the group with the prediction of vaginal delivery. CONCLUSIONS: Labour simulation software can be helpful only in such cases where an arrest of delivery was predicted. The accuracy of delivery simulation with the Anapelvis software was considerably affected by the quality of antenatal foetal ultrasound biometry.

Continuous independent quality control for fetal ultrasound biometry provided by the cumulative summation technique.

OBJECTIVE: To apply the cumulative summation (CUSUM) technique for an evaluation of the learning process of sonographic fetal weight estimation at term in combination with the z-scores of biometry determinants and to assess the time of appearance and sources of errors. METHODS: Learning curve (LC-CUSUM) and double CUSUM charts for systematic error detection based on absolute and signed mean percentage error were generated to retrospectively estimate the longitudinal accuracy of sonographic fetal weight estimation conducted by three trainees and one experienced examiner. For LC-CUSUM analysis an examination was considered to be a failure when there was an absolute error in birth weight estimation >/= 15%. Fetal biometry measurements (head circumference, abdominal circumference (AC) and femur length (FL)) from 227 routine ultrasound scans of one examiner were separately transformed into z-scores and double CUSUM charts were generated to assess the systematic errors for each determinant. RESULTS: The LC-CUSUM charts revealed that different numbers of scans are required for different examiners to achieve competence in estimating birth weight. AC and FL deviated most significantly from expected values (P < 0.05). The double CUSUM charts revealed exact periods of systematic errors in the measurement of biometry determinants, clearly reflecting errors of fetal weight estimation. CONCLUSIONS: The use of CUSUM techniques in the analysis of sonographic data allows observation of the development of an examiner's skill and maintenance of competence. The CUSUM technique not only allows the reasons for impaired fetal weight estimation to be revealed but also allows determination of the exact time when inaccurate measurements start to occur. We suggest that CUSUM charts should be implemented in routine clinical practice as a measure of objective quality evaluation of sonographic fetal biometry.

Sonographic prediction of macrosomia cannot be improved by combination with pregnancy-specific characteristics.

OBJECTIVE: To evaluate the predictive value of a combination of sonographic, clinical and demographic data for detecting fetal macrosomia compared to ultrasound fetal weight estimation alone. METHODS: Retrospective cohort data were obtained from 1062 pregnancies in an unselected population. Estimated fetal sonographic weight was obtained within the last week prior to delivery. Two different combination models-published by Mazouni et al. and Nahum and Stanislaw-were employed to predict the presence of macrosomia at birth in these infants. Receiver-operating characteristics (ROC) curves were generated to compare the prediction of macrosomia when using different observation methods and sensitivity, specificity, positive predictive value, negative predictive value (NPV) and accuracy were calculated. RESULTS: Macrosomia (birth weight >or= 4000 g) was present in 135/1062 (12.7%) newborns. ROC curve analysis revealed the prediction of macrosomia using ultrasound alone to be significantly superior to the combined method of Mazouni et al. (area under the curve (AUC) 0.922, 95% CI 0.902-0.943 vs. 0.747, 95% CI 0.700-0.794, respectively; P < 0.0005), whereas the performance of the Nahum and Stanislaw equation was similar but not superior to ultrasound alone (AUC 0.895, 95% CI 0.839-0.950 vs. 0.912, 95% CI 0.867-0.958, respectively; P > 0.05). The accuracy of macrosomia prediction was similar for ultrasound alone and the Nahum and Stanislaw equation (approximately 90%), whereas the nomogram of Mazouni et al. reached only 51.7% accuracy (using a probability cut-off level of 50%). The NPV was found to be over 90% for all methods. CONCLUSIONS: Combination of sonographic estimates with clinical and demographic variables does not improve the prediction of macrosomia at delivery in comparison with a routine ultrasound scan within a week before delivery, at least in unselected populations.

Decreased umbilical artery compliance and igf-I plasma levels in infants with intrauterine growth restriction - implications for fetal programming of hypertension.

Epidemiological studies link intrauterine growth restriction (IUGR) to arterial hypertension in adulthood. We compared umbilical arteries from IUGR (n=12, <5th weight percentile) vs. appropriate for gestational age (AGA) infants (n=12) using structural and functional analyses. The vessel wall area of umbilical arteries in the IUGR group was significantly smaller than in the AGA group (2.8 vs. 3.8mm(2), P<0.05). Myographic measurements showed that maximal tension [mN/mm] as well as maximal force [mN] were both significantly increased in IUGR arteries compared with AGA arteries (P<0.05). Serum levels of IGF-I, a regulator of elastin synthesis, were significantly lower in IUGR cord blood (P<0.01) than in AGA cord blood. These IGF-I serum levels correlated significantly with maximum tension in umbilical arteries (P<0.01). Low intrauterine IGF-I serum levels may account for thinner and stiffer umbilical arteries in IUGR infants in comparison to AGA infants thereby providing a potential link to arterial hypertension in adulthood.

Extreme statistics for time series: distribution of the maximum relative to the initial value.

The extreme statistics of time signals is studied when the maximum is measured from the initial value. In the case of independent, identically distributed (iid) variables, we classify the limiting distribution of the maximum according to the properties of the parent distribution from which the variables are drawn. Then we turn to correlated periodic Gaussian signals with a 1/falpha power spectrum and study the distribution of the maximum relative height with respect to the initial height (MRHI). The exact MRHI distribution is derived for alpha=0 (iid variables), alpha=2 (random walk), alpha=4 (random acceleration), and alpha=infinity (single sinusoidal mode). For other, intermediate values of alpha , the distribution is determined from simulations. We find that the MRHI distribution is markedly different from the previously studied distribution of the maximum height relative to the average height for all alpha. The two main distinguishing features of the MRHI distribution are the much larger weight for small relative heights and the divergence at zero height for alpha>3. We also demonstrate that the boundary conditions affect the shape of the distribution by presenting exact results for some nonperiodic boundary conditions. Finally, we show that, for signals arising from time-translationally invariant distributions, the density of near extreme states is the same as the MRHI distribution. This is used in developing a scaling theory for the threshold singularities of the two distributions.