Renate Huch

Using fasting plasma glucose concentrations to screen for gestational diabetes mellitus: prospective population based study

Abstract Objective: To evaluate whether measuring fasting plasma glucose concentration is an easier screening procedure for gestational diabetes mellitus than the 1 hour 50 g glucose challenge test. Design: Prospective population based study. Setting: Outpatient clinic in a university hospital. Participants: 520 pregnant women (328 (63%) white, 99 (19%) Asian, 31 (6%) African, 62 (12%) others) with mean age 28.4 (SD 0.2; range 17-45) years. All underwent a glucose challenge test between the 24th and 28th gestational week, followed by a diagnostic 3 hour 100 g oral glucose tolerance test within one week. This was done irrespective of the result of the challenge test. Main outcome measure: Receiver operating curves were used to determine the best cut off values for screening with fasting plasma glucose concentrations. Results: Fasting plasma glucose concentration at a threshold value of 4.8 mmol/l and the glucose challenge test with a threshold value of 7.8 mmol/l yielded sensitivities of 81% and 59% respectively and specificities of 76% and 91% respectively. Measuring fasting plasma glucose concentration as a screening procedure required a diagnostic test in 30%, compared with 14% when the challenge test was used. Conclusions: Measuring fasting plasma glucose concentrations using a cut off value of ≥4.8 mmol/l is an easier screening procedure for gestational diabetes than the 50 g glucose challenge test and allows 70% of women to avoid the challenge test. Key messages Identifying women susceptible to gestational diabetes is particularly important not only to prevent perinatal morbidity but also to improve long term outcomes for the mother and her child Measuring fasting plasma glucose concentration is an easier screening procedure for gestational diabetes than the 1 hour 50 g glucose challenge test With a threshold value of 4.8 mmol/l it yields a sensitivity of 81% and a specificity of 76% Measuring fasting plasma glucose concentration allows 70% of women to avoid a glucose challenge test

Fetal ultrasound biometry: 1. Head reference values

Objective To create reliable reference ranges and calculate Z scores for fetal head ultrasound biometry using a large sample size which is evenly distributed from 12 to 42 weeks of pregnancy.

Ultrasonographic fetal weight estimation: accuracy of formulas and accuracy of examiners by birth weight from 500 to 5000 g.

Abstract Objective: To determine the accuracy of birth weight in different birth weight (BW) groups using widely accepted formulas for fetal weight estimation (EFW). The secondary purpose was to estimate the role of examiners on the accuracy of EFW. Methods: The cross-sectional data were obtained from 5612 pregnant women. Fetal weight was estimated for each fetus using the formulas of Campbell and Wilkin, Shepard, 2 formulas of Hadlock and Merz. Inclusion criteria were: singleton pregnancy, complete ultrasound parameters, EFW obtained within the last week prior to delivery, the live born infant without congenital malformations or hydrops. Results: The highest intraclass correlation coefficient and the most stable results in all BW groups were generated with both Hadlock formulas. Both Hadlock and Campbell formulas had the lowest percent errors (PE) in BW groups between <1500 g and 3500 g. Shepard and Merz formulas had lower PEs in BW groups between 3501 g and >4000 g. However in BW groups under 3500 g they were imprecise. The PE of EFW varied from −4.0±8.5% to 1.3±8.5% between examiners. Conclusions: 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.

Fetal ultrasound biometry: 2. Abdomen and femur length reference values

Objective To create reliable reference ranges and calculate Z scores for fetal abdomen and femur ultrasound biometry using a large sample size which is evenly distributed from 12 to 42 weeks of pregnancy.

Parenteral iron therapy in obstetrics: 8 years experience with iron -sucrose complex

Fe is an essential component of haem in myoglobin and accounts for 70 % of haemoglobin. The balance of Fe, unlike that of other metals such as Na or Ca, is regulated solely by gastrointestinal absorption, which itself depends on the bioavailability of Fe in food, i.e. the chemical Fe species. Factors that maintain Fe homeostasis by modulating Fe transfer through the intestinal mucosa are found at the luminal, mucosal and systemic levels. Fe deficiency and its consequence, Fe-deficiency anaemia, form the commonest nutritional pathology in pregnant women. The current gold standard to detect Fe deficiency remains the serum ferritin value. Previously there was general consensus against parenteral Fe administration, i.e. parenteral Fe was only recommended for special conditions such as unresponsiveness to oral Fe, intolerance to oral Fe, severe anaemia, lack of time for therapy etc. However, especially in hospital settings, clinicians regularly face these conditions but are still worried about reactions that were described using Fe preparations such as Fe-dextrans. A widely used and safe alternative is the Fe-sucrose complex, which has become of major interest to prevent functional Fe deficiency after use of recombinant erythropoietin Numerous reports show the effectiveness and safety of the Fe-sucrose complex. Good tolerance to this Fe formulation is partly due to the low allergenic effect of the sucrose complex, partly due to slow release of elementary Fe from the complex. Accumulation of Fe-sucrose in parenchyma of organs is low compared with Fe-dextrans or Fe-gluconate, while incorporation into the bone marrow for erythropoiesis is considerably faster. Oral Fe is only started if haemoglobin levels are below 110 g/l. If levels fall below 100 g/l or are below 100 g/l at time of diagnosis, parenteral Fe-sucrose is used primarily. In cases of severe anaemia (haemoglobin <90 g/l) or non-response to parenteral Fe after 2 weeks, recombinant erythropoietin is considered in combination. By using parenteral Fe-sucrose in cases of severe Fe deficiency, anaemia during pregnancy is treated efficiently and safely according to our results and rate of blood transfusion could be reduced considerably to below 1 % of patients per year.

rh-Erythropoietin stimulates immature reticulocyte release in man

The pharmacodynamics of single intravenous dosing with recombinant human erthropoietin (rhEPO) was investigated in eight healthy volunteers (150U/kg, n = 2; 300 U/kg, n = 6) with respect to reticulocyte subdivisions (by fluorescence flow cytometry) and serum ferritin over 6.5 d. The present study shows that bolus rhEPO injection produces an immediate release of high and middle fluorescence (immature) reticulocytes with a high RNA content from the marrow into the circulation, whereas the low fluorescence (more mature) reticulocytes were at first not affected. Serum ferritin decreased markedly within 24 h, reaching a nadir 50% of baseline after 120h (5 d), with no increase in haemoglobin. Our data suggests that rhEPO triggers premature expulsion of immature reticulocytes from the bone marrow into the circulation independent of its effect in stimulating erythropoiesis and that rhEPO has an effect on serum ferritin concentration which in this dynamic situation is dependent not only on the iron stores.

Pulse oximetry used for documenting oxygen saturation and right-to-left shunting immediately after birth

The objective of this study was to investigate the clinical applicability of pulse oximetry to measure haemoglobin oxygen saturation and heart rate in the first 20 min of life and to analyse the effect of pre- or postductal (hand, respectively, foot) fixation of sensors on oxygen saturation. Measurements were carried out on 53 newborn infants selected at random after delivery by caesarean section. Signal detection occurred significantly faster from the hand (50% after 1.3 min, 90% after 4 min) than from the foot (50% after 3.1 min, 90% after 9 min). Both fixation sites showed equally great sensitivity to motion. The heart rates from pulse oximetry recordings were up to 30% lower than those from ECG recordings. Saturation values from the hand were nearly always higher than those from the foot (median difference in the 5th min was 10%; between the 5th and 10th min it was 7%; no significant difference occurred after the 17th min). We conclude that pulse oximetry can be used for documenting oxygenation and right-to-left shunting in newborn infants during the first minutes of life in spite of limitations due to incomplete pulse wave detection and artifacts.

MR Autopsy in Fetuses

Objective: The purpose of this study was to determine whether postmortem magnetic resonance imaging (MR autopsy) could serve as an alternative to necropsy of fetuses. The value of MR autopsy in the validation of the obstetric management and in risk counseling concerning future pregnancies is discussed. Methods: 10 consecutive, malformed fetuses were examined by postmortem MRI within 24 h of delivery. Prenatal ultrasound (US) was performed in all fetuses. Complete necropsy served as gold standard. Results: MR autopsy confirmed every US diagnosis responsible for termination. All MRI findings were confirmed by necropsy. In two fetuses, necropsy gave additional information relevant for risk counseling. Histologic examination corrected the diagnosis in one case. Conclusions: MR autopsy provides valuable information previously only available from necropsy. In parents who refuse perinatal necropsy, the information obtained by MR autopsy can be used to validate obstetric management and to evaluate the risk for future pregnancies. Necropsy however remains the gold standard.

Intrapartum reflectance pulse oximetry: effects of sensor location and fixation duration on oxygen saturation readings

Objective. To determine the effects of sensor location and suction fixation duration on measurements of intrapartum fetal oxygen saturation (SpO2) with a new reflectance pulse oximetry system. Design. Fetal SpO2 values (n = 18) were determined in the first stage of labor before and after moving the sensor to another part of the fetal head. Results. Mean fetal SpO2 values did not differ with sensor location (95% CI: −3.59 to 1.48). The duration of measurement period 1, before moving the sensor, was 104 ± 44 (range 30–240) min. No time-dependent changes in SpO2 values were seen (r = 0.17). Conclusion. Suction is an effective and noninvasive method of securing the reflectance pulse oximetry sensor to the fetal head in the first stage of labor and does not interfere with reproducible SpO2 values over several hours.

Dandy–Walker malformation: prenatal diagnosis and outcome

Prenatal ultrasound identified Dandy–Walker malformation (DWM) in ten singleton pregnancies with concurrent central nervous system (CNS) anomalies and extra‐CNS anomalies in eight cases. DWM was confirmed by postnatal magnetic resonance imaging (MRI) or pathological examination in nine cases. Karyotypes were normal in the seven infants tested. Postnatal neurological and developmental testing in the five survivors showed a spectrum of clinical outcome from minor defects to severe handicap. Postnatal investigation also disclosed additional CNS and extra‐CNS findings not detected on ultrasound, as did autopsy in the other five infants. However, ultrasound diagnosis of DWM is accurate and is an indication for exhaustive screening for concurrent anomalies both within and outside the CNS and in chromosome structure and number, as the prognosis is heavily dependent on associated malformations and karyotype. Copyright