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R L Deter

Publications and source records attributed to R L Deter.

At least 37 records · Page 2Linked to original sources
PubMed1994

Prediction of neonatal crown-heel length in normal singletons, twins, and triplets using individualized growth assessment.

In groups of normally growing singletons (20), twins (20), and triplets (13), predicted femur diaphysis length (FDL) values at birth were obtained using Rossavik growth models specified from second-trimester ultrasound studies of fetal growth. Six previously published functions were utilized to obtain predicted crown-heel length (CHL) values from predicted FDL values. These values were compared to the actual CHL values and the percent differences calculated. Based on their systematic (mean percent difference) and random (standard deviation of percent difference) prediction errors, the functions of Vintzileos (singletons), Hadlock (twins), and Brown (triplets) were found to give optimal results (no systematic error; random error: +/- 6%). Using predicted CHL values obtained with these optimal functions, growth potential realization index values for CHL (GPRICHL) were determined for singletons, twins, and triplets. In all three groups, the mean GPRICHL value was 100% with a range of approximately 95% to 105%. These results indicate that the CHL can be predicted from second-trimester growth patterns and evaluated using individualized growth assessment methods.

Embryonic and Fetal Development↗
PubMed1993

Evaluation of triplet growth status at birth using individualized growth assessment: comparison with conventional methods and development of a new classification system.

A new growth classification system for triplets based on individual growth curve standards provides new information on the growth status of triplets at birth. OBJECTIVES. The objectives of this study were to characterize growth outcome at birth in triplet pregnancies using Individualized Growth Assessment methods, and to compare these results to conventional methods of growth outcome evaluation. STUDY DESIGN. Rossavik growth models derived from second-trimester ultrasound measurements were used to predict the birth characteristics of 21 triplet neonates. Actual measurements of weight, head, abdominal, and thigh circumferences at birth were compared to population standards and to predicted values, the latter by calculation of Growth Potential Realization Index (GPRI) values. GPRI values were calculated using singleton (measurement procedure correction) and triplet (measurement procedure correction+decreased soft tissue deposition) correction factors (SCF, TCF). Neonatal Growth Assessment Scores (NGAS) were calculated using both sets of GPRI values. RESULTS. Three types of triplet neonates were identified. Group I (33.3%) were normal with both types of NGAS values, had very few abnormal GPRI values or anatomic measurements, and were all appropriate for gestational age. Group III (14.3%) were abnormal with both types of NGAS values, most GPRI values were abnormal, and all were small for gestational age. Group II (52.4%) had abnormal NGAS values when calculated from GPRI values determined with SCF and normal NGAS values when calculated from GPRI values determined with TCF. All but one was AGA. Almost all GPRIWT and GPRIThC values were abnormal using SCF and normal using TCF. CONCLUSION. Although growth outcome in triplet neonates can be normal (Group I) or intrauterine growth retarded (Group III), the majority are in an intermediate group (Group II) characterized by a decrease in soft tissue mass, which may or may not be pathological.

Adult↗
PubMed1993

Mathematical modeling of fetal organ growth using the Rossavik growth model: II. Adrenal gland.

Growth of the fetal adrenal gland has been monitored by measurements of the circumference (AGC) and area (AGA) of the adrenal gland from 16 to 40 weeks menstrual age. Growth curves for these parameters have been determined using a Rossavik growth curve models [P = c(t)k + s(t)]. R2 values of 86.2 and 91.1% were obtained for AGC and AGA, respectively. Variability analysis indicated a progressive increase in variability with menstrual age for these two parameters. Variability data were used with the growth curve models to determine standard curves for AGC and AGA. These standard curves provide a superior means for evaluating the adrenal growth in the fetus and the fetal status in utero in high-risk pregnancies.

Adrenal Glands↗
PubMed1992

Effect of measurement variability on Rossavik growth model specification and prediction of growth outcome at birth.

We have studied how variability in second-trimester ultrasound measurements affects the process of fetal growth evaluation based on individual fetal growth curve standards specified by Rossavik growth models. The head and abdominal short axes of two second-trimester scans of a patient with normal fetal growth were increased or decreased by increments ranging from 0.1 cm to values equal to the two standard deviations of the interobserver variability for these measurements--i.e., 0.3 cm for head short axis and 0.4 cm for abdominal short axis. The largest increments affected the Growth Potential Realization Index for weight at birth by 1% to 13% when applied to head short axis, and by 2% when applied to abdominal short axis. In contrast, the same increments had little effect (1%) on the Growth Potential Realization Indices for head and abdominal circumferences. Whereas 0.1-cm increments had no effect on any of the individual growth models or predicted birth characteristics, some combinations of these small errors involving both head and abdominal short axes changed the Growth Potential Realization Index for weight by as much as 15%, and those for head and abdominal circumferences by 3% and 8%, respectively. Under some scenarios, fetal growth status could be falsely classified as normal or abnormal. These results show that the reliability of individualized growth assessment depends to a great extent on excellent ultrasound technique, at least for certain parameters.

Birth Weight↗
PubMed1992

Mathematical modeling of fetal splenic growth: use of the Rossavik growth model.

Growth of the fetal spleen has been monitored by measurements of the maximal length (SL), profile circumference (SC), and profile area (SA) of the spleen, from 20 weeks to 41 weeks, menstrual age. Growth curves for these parameters have been determined using a specially developed growth curve model [P = c(t)k + s (t)]. R2 values of 94.3%, 94.9%, and 96.3% were obtained for SL, SC, and SA, respectively. Variability analysis indicated some progressive increase in variability with menstrual age for these three parameters. Variability data were used with the growth curve models to determine standard curves for SL, SC, and SA. These standard curves provide a superior means for evaluating the normal splenic growth in the fetus and for identifying splenic abnormalities in utero.

Embryonic and Fetal Development↗
PubMed1992

Middle cerebral artery flow velocity waveforms in normal and small-for-gestational-age fetuses.

The middle cerebral artery flow velocity waveforms were obtained in 16 normal fetuses in a longitudinal study and in 128 normal fetuses in a cross-sectional study with pulsed Doppler ultrasonography. The pulsatility index values of the middle cerebral artery were higher at 25 to 30 weeks' gestation than those observed during the two periods of major cerebral cellular multiplication in the human fetus. In 9 of the 16 fetuses studied longitudinally we compared the pulsatility index values obtained at the end of gestation with those obtained at 1 month after delivery; no significant difference was observed. The pulsatility index of the middle cerebral artery was also determined in 33 small-for-gestational-age fetuses. A middle cerebral artery pulsatility index value below our normal range was recorded in 9 of the 33 small-for-gestational-age fetuses (27.3%). These small-for-gestational-age fetuses with abnormal pulsatility index values had a significantly higher incidence of abnormal fetal heart rate and admission into the neonatal intensive care unit. There were three deaths in the nine small-for-gestational-age fetuses with abnormal pulsatility index values (33.3%) and three deaths in the 24 small-for-gestational-age fetuses with normal pulsatility index values (12.5%). Our data indicate that the pulsatility index of the middle cerebral artery in the normal human fetus has a parabolic pattern during pregnancy and does not change significantly after delivery. The results suggest that the small-for-gestational-age fetus with a normal middle cerebral artery pulsatility index is at lower risk than the fetus with abnormal pulsatility index values; moreover, management of the small-for-gestational-age fetus may be aided by the study of the middle cerebral artery waveforms.

Blood Flow Velocity↗
PubMed1992

Amniotic fluid volume assessment: comparison of ultrasonographic estimates versus direct measurements with a dye-dilution technique in human pregnancy.

OBJECTIVE: The purpose of our study was to compare the accuracy of clinical ultrasonographic techniques of amniotic fluid volume assessment with a dye-dilution technique. STUDY DESIGN: We compared amniotic fluid volume as measured by ultrasonographic techniques with a dye-dilution method in 50 women undergoing amniocentesis during the third trimester. Thirteen separate ultrasonographic techniques, including the amniotic fluid index, were evaluated with regression analysis. RESULTS: Amniotic fluid volumes as determined by dye-dilution ranged between 129 and 4444 ml. The amniotic fluid index overestimated the actual volume by as much as 88.7% at lower volumes and underestimated the actual volume by as much as 53.9% at higher volumes. CONCLUSIONS: Differences in measurement error between the other ultrasonographic methods and the amniotic fluid index did not appear to be sufficient to warrant changes in current clinical practice. A major source of error in ultrasonographic amniotic fluid volume assessment is that one-dimensional measurements are used to estimate the volume of a complex, three-dimensional object.

Amniotic Fluid↗
PubMed1991

Doppler assessment of renal blood flow velocity waveforms in the anemic fetus before and after intravascular transfusion for severe red cell alloimmunization.

Image-directed pulsed Doppler ultrasonography demonstrated a decrease in the pulsatility index of the renal artery in 9 anemic fetuses (less than 30 weeks, menstrual age) soon after intravascular transfusion. The pulsatility index returned to pretransfusion values the day following the transfusion. End diastolic blood velocity in the renal artery could not be measured before the transfusion, was detectable immediately after the procedure, and was again nonmeasurable one day after the transfusion. These data suggest an increase in renal blood flow in the anemic fetus soon after intravascular transfusion to eliminate excess fluid.

Anemia↗
PubMed1991

Individual growth curve standards in triplets: prediction of third-trimester growth and birth characteristics.

We investigated the ability of Rossavik growth models, determined from measurements obtained before 24 weeks (head circumference [HC], abdominal circumference [AC], femur diaphysis length, and estimated fetal weight [EFW]) or 25 weeks (thigh circumference), to predict third-trimester growth and birth characteristics in normally growing triplets. Comparisons of coefficient c values for six anatomical measurements indicated no statistically significant differences in the second-trimester growth of triplets, twins, and singletons. Third-trimester triplet values for HC, AC, and femur diaphysis length were predicted with an accuracy of +/- 6-8%. For thigh circumference and EFW, the comparable values were +/- 17 and +/- 15%, respectively. The HC at birth was predicted without bias; the random error was approximately -27 to 9.0%. Weight, AC, and thigh circumference were systematically overestimated (16.5, 20.9, and 16.3%, respectively). After correction for systematic errors, these characteristics could be predicted with random errors of -13.0 to 9.5% (weight), -12.0 to 2.8% (AC), and -16.7 to 11.3% (thigh circumference). Growth Potential Realization Index values had means of approximately 100% and ranges from 90-121%. The mean triplet value of the Neonatal Growth Assessment Score was 13.6, ranging from 2.8-26.5. These results are similar to those for singletons and twins and indicate that individual assessment of growth in triplets can be performed with the same methods used for both singletons and twins.

Adult↗
PubMed1991

Detection of macrosomia by the individual fetal growth curve assessment method.

The value of the Rossavik growth model [P = c(t)k + s(t)] was evaluated in 39 patients with singleton pregnancy who had neonatal weight outcome above the 90th percentile of our birth weight distribution for gestational age. Individual fetal growth curve standards for head and abdominal circumferences, femur diaphysis length, and weight were determined from the data of two scans obtained before 26.1 weeks' gestation and separated by an interval of at least 5 weeks. Projected crown-heel lengths were calculated from projected femur diaphysis length values. Comparisons between actual and predicted birth characteristics were expressed by the Growth Potential Realization Index (GPRI) and Neonatal Growth Assessment Score (NGAS). Excessive growth at birth was seen in almost all cases as indicated by high GPRI for weight and abdominal circumference and abnormal NGAS values. In eight of the 33 patients who delivered after 38 weeks, excessive growth was detected only by comparing birth characteristics to their predicted values at 38 weeks' gestation. Our data suggest that individual growth curve standards may identify several patterns of excessive fetal growth that could represent different pathophysiologic mechanisms, ie, failure to terminate growth after 38 weeks versus a defect in a still unknown growth regulator. The individual fetal growth curve standards method gives additional information and discriminates well between normal and excessive fetal growth.

Birth Weight↗
PubMed1990

Definition of anatomical planes for use in transvaginal sonography.

Planes frequently used to identify radiologic and abdominal ultrasonographic images such as transverse, coronal, and sagittal are generally not anatomically correct when applied to transvaginal ultrasonographic planes and images. More appropriate terminology specific for the planes imaged during transvaginal ultrasonography, such as TRANS-pelvic and AP-pelvic planes, are suggested. A TRANS-pelvic plane refers to a plane imaged when the sound beam is directed across or from side to side in the pelvis. An AP-pelvic plane refers to an image obtained when the sound beam is directed anteriorly and posteriorly.

Female↗
PubMed1990

Neonatal growth assessment score: a new approach to the detection of intrauterine growth retardation in the newborn.

To develop an improved means for evaluation of the outcome of fetal growth in utero, a growth study of 37 fetuses at risk for intrauterine growth retardation was undertaken. Intrauterine growth was evaluated with ultrasonography at 2- to 3-week intervals beginning at 15 weeks' gestation. Measurements obtained in the second trimester were used to specify Rossavik growth models for various anatomic parameters. Values for weight, head circumference, abdominal circumference, and thigh circumference at birth were predicted with the use of these models. Growth potential realization index values for these four parameters were calculated from actual and predicted birth measurements. The growth potential realization index values were combined to form a neonatal growth assessment score. With the use of cluster analysis and neonatal growth assessment score values, the 37 infants were separated into 24 group I (neonatal growth assessment score values between 3.7 and 18.6) and 13 group II (neonatal growth assessment score values between 19.4 and 50.0) infants. In group I, 66.7% of the infants had no growth abnormalities; a single abnormality, usually borderline, was found in an additional 20.8% (total = 87.5%). In group II all infants had growth abnormalities (range, 2 to 6) although only 46.2% had birth weights below the 10th percentile. No differences in risk factors (except for the incidence of smoking) or second trimester growth were found in these two groups. The neonatal growth assessment score appears to be a sensitive indicator of third trimester growth retardation, is not affected by differences in growth potential, can separate normal infants from those with evidence of intrauterine growth retardation, and provides a quantitative assessment of growth problems in individual fetuses.

Adult↗
PubMed1990

Flow velocity waveforms of the vascular system in the anemic fetus before and after intravascular transfusion for severe red blood cell alloimmunization.

Sixteen intravascular transfusions were performed in 16 anemic human fetuses. To investigate the status of the vascular system with Doppler ultrasonography before and after correction of anemia, pulsatility index values were obtained for the flow velocity waveforms of the middle cerebral artery, internal carotid artery, anterior cerebral artery, thoracic aorta, abdominal aorta, renal artery, femoral artery, and umbilical artery before and the day after the correction of anemia. The fetuses were divided into two groups: (1) fetuses with a hematocrit level between 2 and 4 SDs below the normal mean value for gestational age and (2) fetuses with a hematocrit value less than 4 SDs below the normal mean value for gestational age. No significant differences were observed in the pulsatility index values of the vessels studied before and after correction of anemia in both groups of fetuses. These data suggest that the pulsatility index cannot be used as an indicator of fetal anemia at the hematocrit values studied.

Anemia, Hemolytic, Autoimmune↗
PubMed1990

Flow velocity waveforms of the umbilical and cerebral arteries before and after intravascular transfusion.

Thirteen intravascular transfusions were performed in 13 human fetuses who were anemic because of severe red-cell alloimmunization. To investigate the status of the umbilical and cerebral circulations by pulsed Doppler ultrasound, we studied the fetal middle cerebral artery (N = 13), internal carotid artery (N = 11), anterior cerebral artery (N = 11), and umbilical artery (N = 13) before, within the first 2 hours after, and the day after intravascular transfusion. The gestational age at the time of transfusion was 21-31 weeks (mean +/- SD 25 +/- 3.1). The fetal hematocrits before transfusion ranged from 12-32% (23.4 +/- 6.1), whereas the hematocrit after transfusion was between 25-42% (35 +/- 5). The net blood volume transfused (volume infused--volume removed) ranged between 7.5-31.0 mL (16.0 +/- 7.4). The hematocrit of the transfused blood varied between 68-81% (74 +/- 4). Repeated-measures analysis of variance indicated significant differences in the pulsatility index values of the four vessels studied. The same analysis indicated significant differences in the pulsatility index values at the three time points. Multiple comparison tests showed that the pulsatility index was reduced significantly immediately after transfusion for each vessel studied, but returned to pretransfusion levels by the next day. These data suggest a change in vascular impedance soon after transfusion as a consequence of direct intravascular transfusion.

Anemia↗
PubMed1990

Uterine blood flow velocity waveforms in pregnant women during indomethacin therapy.

Continuous-wave Doppler ultrasound was used to assess blood flow velocities and determine the pulsatility index of the uterine arteries in ten pregnant women at 23-33 weeks' gestation during indomethacin therapy for preterm labor or polyhydramnios. There was no statistically significant difference in the pulsatility index of the uterine arteries during maternal indomethacin treatment (mean +/- SD 0.85 +/- 0.29) compared with pre-treatment values (0.85 +/- 0.23). Although studies in animals have reported that indomethacin increases uterine impedance to flow, it appears that it does not affect the uterine impedance in humans.

Blood Flow Velocity↗
PubMed1990

Doppler assessment of the renal blood flow velocity waveform during indomethacin therapy for preterm labor and polyhydramnios.

To investigate the effects of indomethacin on the human fetal renal blood flow velocity waveform, 17 fetuses whose mothers were treated for preterm labor (N = 8) or polyhydramnios (N = 9) were studied. There were five growth-retarded fetuses (all in the group with polyhydramnios), 11 normal fetuses, and one fetus with red-cell alloimmunization. The indomethacin dose in all patients was 25 mg orally every 6 hours. The gestational age of the fetuses studied varied between 24-35 weeks (mean +/- SD 29.6 +/- 2.8). The fetal renal artery was studied at its origin from the aorta before and during the first 24 hours of indomethacin therapy. Seven fetuses manifested ductal constriction. Three fetuses also manifested tricuspid regurgitation. All ductal constrictions and the tricuspid regurgitations resolved in utero after discontinuation of indomethacin. There were no significant differences in the pulsatility index values of the renal artery before and during indomethacin therapy. These results suggest that there is no change in fetal renovascular parameters detectable with pulsatility index measurements during the first 24 hours of maternal indomethacin therapy.

Ductus Arteriosus↗