Objective To create reliable reference ranges and calculate Z scores for fetal head ultrasound biometry Design A prospective, cross-sectional study.Setting Obstetric clinics (outpatient and delivery units) at the University Hospital of Zurich.Sample The study data were obtained from 6557 pregnant women.Methods Only the first ultrasound examination between 12 and 42 weeks of each fetus with exactly established gestational age was used for analysis. No exclusions were made on the grounds of small-for-date birthweight, prematurity or other events several weeks after the examination. Separate regression models were fitted to estimate the mean and standard deviation at each gestational age for each parameter.Results A total of 6217 fetal head biparietal diameters and 5510 occipito-frontal diameters were measured. Both head circumference and cephalic index were derived in 5462 cases where both biparietal diameter and occipito-frontal diameter could be measured on the same fetus. The centile charts, tables and regression formulae for biparietal and occipito-frontal diameters, head circumference and cephalic index are presented. An application to calculate 2 scores was developed using Excel (Microsoft Corporation, USA) and macros are presented in detail in the Figure 8 footnote. The comparison of our charts with those of the two most recent studies revealed almost no differences in biparietal diameter centiles. In one publication, occipito-frontal diameter charts, and in another, head circumference charts were different from the current study.Conclusions We have presented centile charts, tables and regression formulae for fetal head ultrasound biometry derived from a large and minimally selected sample size in a carefully designed cross-sectional study. Complete tables and regression formulae to calculate reference ranges and Z scores are presented for use in computer-aided evaluation of fetal ultrasound biometry.using a large sample size which is evenly distributed from 12 to 42 weeks of pregnancy.

The objective of this cross-sectional study was to construct new reference ranges for Doppler flow velocity waveform resistance indices for the fetal umbilical artery, middle cerebral artery, placental and non-placental uterine arteries and the placentocerebral ratio in a large and minimally selected population attending a single clinic. Study design and data analysis adhered to a number of stringent and validated methodological recommendations derived both from the recent literature and from a review of earlier publications in this field. The final database comprised initial routine Doppler velocimetry at 24-42 weeks' gestation in 1675 pregnancies. Separate regression models were fitted to estimate the mean and standard deviation at each gestational age for each vessel. New charts, centile tables and regression equations are presented for the resistance indices of the fetal umbilical artery, middle cerebral artery, placental and non-placental uterine arteries and the mean of both uterine arteries and for the placentocerebral ratio.

Both Hadlock formulas showed the most stable results in all of the weight groups. There is also a need for routine evaluation of the accuracy of EFW for every examiner, to make suggestions, what fetal measurements must be improved to improve EFW.

Objective To create reliable reference ranges and calculate Z scores for fetal abdomen and femur ultrasound Design A prospective, cross-sectional study.Setting Obstetric clinics (outpatient and delivery units) at the University Hospital of Zurich. SampleThe study data were obtained from 6557 pregnant women. MethodsOnly the fmt ultrasound examination between 12 and 42 weeks of each fetus with certainly established gestational age was used for analysis. No exclusions were made on the grounds of small-for-date birthweight, prematurity or other events several weeks after the examination. Separate regression models were fitted to estimate the mean and standard deviation at each gestational age for each parameter.Results A total of 5807 mean abdominal diameters and abdominal circumferences were derived from fetal transverse and anterio-posterior fetal abdominal diameter measurements. Fetal femur length was measured in 5860 instances. The charts, tables and regression formulae of the biometrical measurements are presented. A comparison of our charts with others showed no significant difference. Only Merz'sl centiles for abdominal biometry were lower and for femur length higher than ours. An application to calculate 2 scores was developed using Excel (Microsoft Corporation, USA); the macros are presented in detail in the Figure 6 footnote. ConclusionsWe have presented centile charts, tables and formulae for fetal abdominal diameter and circumference and femur length derived from a large and minimally selected sample size in a carefully designed cross-sectional study. Complete tables and regression formulae to calculate reference ranges and Z scores are presented to use in computer-aided evaluation of fetal ultrasound biometry.biometry using a large sample size which is evenly distributed from 12 to 42 weeks of pregnancy.

The transparent oxygen electrode, recently developed by Huch and his co-workers, permits monitoring of transcutaneous oxygen tension (tcPo2) at defined sites on the capillaroscopic image obtained by videomicroscopy. This combined system has been applied to study the nutritional skin capillaries of patients with chronic venous incompetence (CVI). 806 simultaneous measurement of the oxygen tension of the skin (tcPo2) and examination of the nutritional skin capillaries at the monitoring site by videomicroscopy. This combined system was applied in the study of 17 patients with CVI and the results were compared with those obtained in a group of 24 healthy subjects. Materials and methodsPatients. The CVI group consisted of 17 patients (six women, 1 1 men) with a mean age of 56 years (range 22 to 76). Fortyfour measurements were obtained in this group. The method of selection of sites of measurement is described below.In 12 patients CVI was caused by deep venous thrombosis (obstruction and/or incompetence of deep veins, incompetent perforating veins) and in five CVI resulted from primary varicose veins with incompetent perforating veins.Nine patients had trophic skin changes without ulcers and eight had trophic skin changes with ulcers or healed ulcers. The diagnosis was based on patient history, clinical findings, and results of Doppler ultrasound examination. Venograms were obtained in seven patients.No patient had clinical evidence of peripheral arterial occlusive disease. Palpation of pulses, auscultation, and photoplethysmography at the big toe were normal in all cases.Control subjects.