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Objective: To compare the precision of biparietal diameter (BPD) and crown–rump length (CRL) as predictors of gestational age in the human fetus in the late first and early second trimesters, using a population‐based approach. Methods: We constructed term and gestational‐age prediction curves for first‐trimester dating, based on 11 041 pregnancies with 12 260 measurements of CRL and/or BPD from a population‐based Norwegian clinical database. We used a population‐based approach with local linear quantile regression, combined with a time‐to‐event strategy that compensates for induced births. Term prediction precision was assessed by estimating and comparing the prediction residual curves using a time‐to‐event analysis. Individual differences in gestational‐age predictions from CRL and BPD were assessed using measurements performed on the same fetus on the same day. A sensitivity analysis was performed to evaluate the effect of not distinguishing between non‐spontaneous and spontaneous births. Results: CRL and BPD provided almost identical term prediction precision judged from the residual distribution. In about 51% of examinations, the difference in predicted gestational age was 1 day or less; 24% of examinations had a difference of 2 days, 14% had a difference of 3 days, 7% had a difference of 4 days and only 5% of all examinations had a difference of 5 days or more. Incorrectly removing induced births from the analysis, or treating them as spontaneous, would cause a substantial systematic prediction bias of about 2 days. Conclusions: Based on population data, using comparisons at an individual level, our study found that BPD is as precise as CRL when used for first‐trimester dating. BPD has advantages from a clinical point of view, since it is technically less challenging and less time‐consuming to measure compared with CRL, and can be measured and assessed throughout the entire pregnancy. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

Objective: To confirm the results from two previous evaluations of term prediction models, including two sample-based models and one population-based model, in a third population. Methods: In a study population of 23,020 second-trimester ultrasound examinations, data were prospectively collected and registered over the period 1988-2009. Three different models for ultrasonically estimated date of delivery were applied to the measurements of fetal biparietal diameter (BPD) and two models were applied to the femur length (FL) measurements; the resulting term estimations were compared with the actual time of delivery. The difference between the actual and the predicted dates of delivery (the median bias) was calculated for each of the models, for three BPD/FL-measurement subgroups and for the study population as a whole. Results: For the population-based model, the median bias was + 0.4 days for the BPD-based predictions and - 0.4 days for the FL-based predictions, and the biases were stable over the inclusion ranges. The biases of the two traditional models varied with the size of the fetus at examination; median biases were - 0.87 and + 2.2 days, respectively, with extremes - 4.2 and + 4.8 days for the BPD-based predictions, and the median bias was + 1.72 days with range - 0.8 to + 4.5 days for FL-based predictions. The disagreement between the two sample-based models was never less than 2 days for the BPD-based predictions. Conclusion: This study confirms the results from previous studies; median biases were negligible with term predictions from the population-based model, while those from the traditional models varied substantially. The biases, which have clinical implications, seem inevitable with the sample-based models, which, even if overall biases were removed, will perform unsatisfactorily. [ABSTRACT FROM AUTHOR]

Objectives Fetal ultrasound measurements are made in axial, lateral and oblique directions. Lateral resolution is influenced by the beam width of the ultrasound system. To improve lateral resolution and image quality, the beam width has been made narrower; consequently, measurements in the lateral direction are affected and apparently made shorter, approaching the true length. The aims of this study were to explore our database to reveal time-dependent shortening of ultrasound measurements made in the lateral direction, and to assess the extent of beam-width changes by comparing beam-width measurements made on old and new ultrasound machines. Methods A total of 41 941 femur length measurements, collected during the time-period 1987-2005, were analyzed, with time as a covariate. Using three ultrasound machines from the 1990s and three newer machines from 2007, we performed 25 series of blinded beam-width measurements on a tissue-mimicking phantom, measuring at depths of 3-8 cm with a 5-MHz transducer. Results Regression analysis showed time to be a significant covariate. At the same gestational age, femur length measurement was 1.15 (95% CI, 1.08-1.23) mm shorter in the time-period 1999-2005 than in the time-period 1987-1992. Overall, the beam width was 1.08 (95% CI, 0.50-1.65) mm narrower with the new machines than with the old machines. Conclusions Technical improvements in modern ultrasound machines that have reduced the beam width affect fetal measurements in the lateral direction. This has clinical implications and new measurement charts are needed. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Objectives To compare results of predictions of date of delivery from a new population-based model with those from two traditional regression models. Methods We included 9046 fetal biparietal diameter (BPD) measurements and 8776 femur length (FL) measurements from the routine ultrasound examinations at Stavanger University Hospital between 2001 and 2007. The prediction models to be validated were applied to the data, and the resulting predictions were compared with the actual time of the subsequent deliveries. The primary measure was the median bias (the difference between the true and the predicted date of delivery), calculated for each method, for the study population as a whole and for three subgroups of BPD/FL measurements. We also assessed the proportion of births within ±14 days of the predicted day, and rates of preterm and post-term deliveries, which were regarded as secondary measures. Results For the population-based model, the median bias was −0.15 days (95% confidence interval (CI), −0.43 to 0.12) for the BPD-based, and −0.48 days (95% CI, −0.86 to −0.46) for the FL-based predictions, and both biases were stable over the inclusion ranges. The biases of the traditional regression models varied, depending on the fetal size at the time of the examination; the extremes were −3.2 and +4.5 days for the BPD-based, and −1.0 and +5.0 days for the FL-based predictions. Conclusions The overall biases, as well as the biases for the subgroups, were all smaller with the populationbased model than with the traditional regression models, which exhibited substantial biases in some BPD and FL subcategories. For the population-based model, the FL-based predictions were in accordance with the BPDbased predictions. [ABSTRACT FROM AUTHOR]

There has been an increasing interest in the use of computer-mediated communication (CMC) in problem-based learning. One line of research has been to introduce synchronous, or simultaneous, communication attempting to create text-based digital real-time interaction. Compared with face-to-face (F2F) communication, CMC may be a poorer medium regarding coordination of the activity. Still, we are in need for more knowledge on the possible advantages and problems regarding such digital communication processes. In the present study, we compared activities in digital and F2F problem-based learning (PBL) regarding the content of the communication, turn-taking processes and the emergence of learning issues. The results indicate that when students discussed in the digital learning environment, they focused more on technical and organizational questions, produced relatively more initiatives but less responses, and produced less elaborated and specified learning issues than when they participated in F2F meetings. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to evaluate fertility and menstrual pattern in women with polycystic ovarian syndrome (PCOS) 15-25 years after ovarian wedge resection (OWR).Methods and Results: The diagnosis was based on the combination of ovarian pathology and symptoms. The 149 patients, all primarily treated at a university teaching hospital, were studied three times by means of a questionnaire up to 25 years after surgery. Kaplan-Meier analysis showed a cumulative rate of spontaneous pregnancies of 76%, increasing to 88% when induced pregnancies were included. The cumulated live birth rate was 78%. A bootstrap simulation indicated that 69.5% would develop post-operative adhesions, which could impede pregnancy in 13.4%. In the majority of the patients a regular menstrual pattern was restored up to 25 years after OWR.Conclusion: The results of OWR in PCOS are favourable to most modern treatments. Laparoscopic electrocautery of the ovaries is the only method equally successful, and, by being less invasive, it has made OWR history in the treatment of PCOS. [ABSTRACT FROM AUTHOR]

Objective To compare gestational age (GA) and day of delivery estimated from the time of in vitro fertilization (IVF) (oocyte retrieval + 14 days), the ultrasonic measurement of the crown–rump length (CRL) and the biparietal diameter (BPD) in pregnancies conceived in an IVF setting. Design Included were 208 singletons and 72 twin pregnancies conceived after IVF. GA estimated from the time of IVF was compared with the GA estimated from the ultrasonic measurement of the CRL in the first trimester and the BPD in the second trimester. Results In singletons the mean difference in gestational age was 0.9 days between IVF and CRL estimates and 2.1 days between IVF and BPD estimates. The gestational age as estimated from CRL or BPD was shorter than the GA estimated from IVF. There was no systematic variation in the mean differences in GA between the methods. In three pregnancies there was a difference of more than 7 days between the gestational age estimated from IVF and CRL and in 22 pregnancies between gestational age estimated from IVF and BPD. A difference of > 14 days for any of the estimates was not found in any case. In singletons there was a high correlation in the gestational age at birth assessed from the time of IVF and from CRL, from the time of IVF and from BPD. Conclusion Assessment of gestational age from the time of IVF, CRL and BPD in pregnancies conceived after IVF shows equally high agreement between the three methods. This supports the use of ultrasound as a reliable method for estimation of gestational age. [ABSTRACT FROM AUTHOR]

Body temperature was studied in 65 patients admitted to hospital within four hours of the onset of symptoms of acute myocardial infarction. Thirty three patients had been randomly assigned to intravenous timolol treatment and 32 to placebo treatment. Infarct evolution was assessed by continuous vectorcardiography and creatine kinase release. Maximum and mean temperatures during the first eight days were significantly lower in the timolol group, who were discharged from hospital one day earlier. Eight patients in the placebo group had temperatures of greater than 39 degrees compared with one in the timolol group. Both the mean temperature and the maximum temperature correlated significantly with indices of infarct size and ischaemic area as estimated by cumulative creatine kinase release, QRS vector difference, and ST vector magnitude. The results were consistent with the view that reduction of infarct size may partly explain the reduced pyrexial response after timolol treatment. Other mechanisms are probably also involved in larger infarcts. Because high fever has detrimental haemodynamic effects in acute myocardial infarction, reduction of this response may be beneficial. The results support the early use of beta adrenoceptor blockade in acute myocardial infarction. [ABSTRACT FROM PUBLISHER]

One hundred and six patients with acute myocardial infarction admitted to hospital within four hours after the onset of symptoms were randomised to treatment with intravenous timolol (54 patients) or placebo (52 patients). Serum potassium concentrations were estimated at frequent intervals during the first 24 hours of admission. Patients in both treatment groups, who did not receive subsequent diuretic treatment, had a transient rise in serum potassium concentration, which was maximal after four hours. This rise was abolished by diuretic treatment in the placebo group but not in the timolol group, in which there was a pronounced and prolonged rise in serum potassium concentration. The change in serum potassium concentration in the first four hours after admission correlated with cumulative creatine kinase release in the placebo group, but not in the timolol group. Hypokalaemia (serum potassium concentration less than or equal to 3.5 mmol/l) occurred in 15 (28.8%) patients in the placebo group and in seven (13%) in the timolol group and was independent of infarct size. The frequency of hyperkalaemia was not increased in the timolol group. By increasing the serum potassium concentration and preventing hypokalaemia, the use of intravenous timolol early in acute myocardial infarction may have important clinical effects in addition to reducing infarct size. [ABSTRACT FROM PUBLISHER]