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Objective: To test whether Schild’s sex-specific formula for estimating fetal weight is more accurate than commonly used regression formulae. Methods: The gender-specific formula and 10 widely used equations were evaluated in a group of 989 pregnancies. Each fetus underwent ultrasound examination with complete biometric parameters within 7 days before delivery. Results: Over the whole weight range and in the subgroup of newborns with a birth weight between 2,500 and 3,999 g, the sex-specific weight formula from Schild demonstrated the best level of accuracy. For infants with a birth weight of less than 2,500 g as well as for macrosomic newborns, the gender-specific formula did not improve fetal weight estimation. Conclusion: In pregnancies where fetal gender is known, Schild’s regression formula should be used when fetal weight lies within the range of 2,500–3,999 g.

Objective: To develop new gender-specific regression formulae to estimate fetal weight focusing on a particular weight range from 2,501 to 3,999 g. Methods: 3,254 singleton pregnancies were included to generate new regression formulae for female and male fetuses, and to evaluate their accuracy. Results: In comparison with commonly used formulae, the new gender-specific and weight-range-specific method of fetal weight estimation provided greater accuracy. The mean absolute error was less than 7%. Conclusions: When properly used, the new formulae can improve the accuracy of weight estimations in fetuses between 2,501 and 3,999 g.

The aim of the study was to analyze the concordance of INR values obtained by educated lay users with those obtained by professionals and to determine the imprecision of the new system. The new CoaguChek XS system was tested in a user study over six weeks at four study centres in Austria, Denmark and Germany. Seventy-five patients receiving oral anticoagulant therapy were enrolled in the study. The INR results in capillary whole blood taken by professionals and by patients using the CoaguChek XS system were similar, and the mean relative bias was <1%. The imprecision of the CoaguChek XS system calculated from duplicate testing is low (<6%) and slightly better than for the established CoaguChek S system. The INR results measured during the home testing phase correlated quite well between the established CoaguChek S system and the new CoaguChek XS system with a mean bias of 0.14 INR. This is a remarkably low bias taking into consideration that more than 30 different test strip lots were applied. A questionnaire was filled out by all patients to assess their personal impression. It revealed that patients were very satisfied with the new system and found it easy to operate. The results demonstrate that the agreement between professional and patient INR results for the new CoaguChek XS system was excellent and that INR values can be determined by lay users as well as by professionals. The instrument is very well accepted by the patients and their satisfaction even increased after four weeks practice at home.