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Biomedical subjects

E F Magann

Publications and source records attributed to E F Magann.

At least 73 records · Page 4Linked to original sources
PubMed1998

Effect of amniotic fluid volume on neonatal outcome in diamniotic twin pregnancies.

PROBLEM: We assessed neonatal outcome of normal diamniotic twin pregnancies with known amniotic fluid (AF) volume. METHOD: The AF volume was empirically determined in 39 diamniotic twin gestations. The neonates were stratified by AF volume and evaluated for clinical outcome, gestational age, lecithin-sphingomyelin (L/S) ratio, and birth weight. RESULTS: Neonatal complications did not significantly differ among infants delivered from pregnancies with low (155 to 404 mL), moderate (405 to 807 mL), or high (808 to 5,430 mL) volumes of AF. Relatively constant volumes of AF were maintained throughout the 27 to 38 week range of gestational age, with no apparent correlation between AF volume and gestational age. Variations in the L/S ratio and newborn birth weights were also independent of AF volume. Gestational age was the only significant determinant of the frequency of neonatal complications. CONCLUSION: Amniotic fluid volume does not greatly affect neonatal outcome in normal diamniotic twin pregnancies.

Adult↗
PubMed1998

Placental implantation at 18 weeks and migration throughout pregnancy.

BACKGROUND: We wanted to find the most frequent site of placental implantation at 18 weeks' gestation and placental migration during gestation. METHODS: Placental location was identified in 2,526 singleton pregnancies at 18 weeks' gestation and characterized into nine groups. Placental migration in 1,336 of these pregnancies was assessed by serial ultrasonography. RESULTS: At 18 weeks' gestation, posterior, high placental implantation was more common (45.1%) than anterior, high implantation (42.1%). Relocation of posterior, high placentas farther fundally (16.9%) was three times more likely than farther fundal migration of anterior, high placentas (4%). CONCLUSIONS: Posterior fundal placental implantation is more common at 18 weeks' gestation than anterior implantation. Posteriorly implanted placentas are more likely than anterior placentas to migrate farther fundally during gestation. The greater relocation of posterior placentas farther fundally suggests a greater growth of posterior versus anterior uterine wall smooth muscle.

Adult↗
PubMed1998

Do multiple measurements employing different ultrasonic techniques improve the accuracy of amniotic fluid volume assessment?

This investigation was undertaken to determine if the accuracy of the ultrasound assessment of abnormal amniotic fluid volume (oligohydramnios or polyhydramnios) is improved by employing multiple sonographic amniotic fluid measurements. Four ultrasound techniques consisting of the subjective assessment (ultrasonic visualization without measurement), largest vertical pocket, amniotic fluid index and 2-diameter pocket technique were performed followed by amniocentesis and dye-dilution confirmation of amniotic fluid volume in 66 singleton pregnancies. The ultrasound accuracy to detect abnormal amniotic fluid volume ranged from 61% with the largest vertical pocket to 70% with the 2-diameter pocket procedure used separately. Receiver operator characteristic curves demonstrated that combining the 4 ultrasonic measurements did not improve the accuracy of identifying amniotic fluid volumes.

Adolescent↗
PubMed1998

Mathematical models to correlate amniotic fluid index and amniotic fluid volume.

PURPOSE: To describe a predictable relationship that relates amniotic fluid index (AFI) to amniotic fluid volume (AFV) and improve the accuracy of AFI to detect true oligohydramnios. METHODS: Data from 42 parturients (group I) who underwent measurements of amniotic fluid sonographically (amniotic fluid index) as well as by dye-dilution technique was used to relate AFI to AFV. Subsequently, 22 consecutive women (group II) were used to test the accuracy of the equation to predict true oligohydramnios. RESULTS: In group II, 11 of 22 patients had true oligohydramnios and the sensitivity, specificity, positive and negative predictive values of AFI < or = 5.0 to detect a confirmed AFV < 500 mL were 0%, 91%, 0%, and 48%, respectively. These values of AFI, when used in conjunction with the equation, improved to 73%, 55%, 62%, 67%, respectively. With AFI and the equation, significantly more patients in group II with true oligohydramnios (8 of 11) could be detected than with using AFI alone (0 of 11; p = 0.002). CONCLUSION: AFI is poor predictor of true oligohydramnios. Using the mathematical model, the detection rate of oligohydramnios is significantly improved.

Amniotic Fluid↗
PubMed1998

Amnioinfusion-induced malpresentation.

Amnioinfusion is a valuable and common intrapartum procedure for the relief of cord compression and to dilute thick meconium. Like most procedures, it is not without risk and we report a case of malpresentation following amnioinfusion. Intrapartum fetal demise occurred after malpresentation during amnioinfusion resulting in a change of fetal presentation from vertex to unrecognized shoulder presentation. Further study is needed regarding changes in volume of amniotic fluid and saline as well as intrauterine manipulation and the effect on fetal presentation. Careful attention must be paid to infused volumes during amnioinfusion.

Adult↗
PubMed1998

Hematological complications of Gaucher's disease in pregnancy.

A case is presented of a 31-year-old Filipino female, gravida 5 para 2, at 38 weeks plus 5 days gestation, with known type I Gaucher's disease who underwent repeat cesarean delivery. After cesarean delivery, the patient developed disseminated intravascular coagulation and required transfusion of eight 6-packs of platelets, 6 units of fresh frozen plasma, two 10-packs of cryoprecipitate, and 6 units of packed red blood cells. Pregnancy is generally well tolerated in patients with type I Gaucher's disease, an autosomal recessive lysosomal storage disorder in which lipid deposits accumulate in the liver, spleen, and bone marrow. Hemorrhagic problems secondary to severe thrombocytopenia may develop postpartum in pregnancies complicated by Gaucher's disease, requiring significant support with blood and blood products.

Adult↗
PubMed1997

The accuracy of ultrasound evaluation of amniotic fluid volume in singleton pregnancies: the effect of operator experience and ultrasound interpretative technique.

The objective of this study was to evaluate the effect of operator experience and ultrasound interpretation technique on the accuracy of ultrasound estimates of amniotic fluid volume. Ultrasound evaluation was carried out by an obstetric resident, a nurse sonographer, a maternal-fetal medicine fellow, and a maternal-fetal medicine staff member to subjectively estimate (visual interpretation without sonographic measurements) amniotic fluid volume in 63 pregnancies. Amniotic fluid volume was also evaluated using ultrasound measurements based on the largest vertical pocket technique, the amniotic fluid index, and the two-diameter pocket method. The accuracy of these ultrasound estimates was assessed by comparing the ultrasound results to actual amniotic fluid volume as determined by a dye-dilution technique. For analysis, amniotic fluid volumes were classified as oligohydramnios, normal, or hydramnios using established volumetric criteria for singleton pregnancies. Subjective estimates ranged from 65% to 70% correct and did not differ by operator experience except for the more accurate diagnosis of hydramnios by the maternal-fetal medicine staff. The three sonographic measurements were similar in overall accuracy (59-67%). The two-diameter pocket method was, however, significantly more accurate in identifying oligohydramnios. It appears that neither operator experience nor sonographic technique greatly affects the accuracy of ultrasound estimates of amniotic fluid volume.

Adolescent↗
PubMed1997

The accuracy of the summated amniotic fluid index in evaluating amniotic fluid volume in twin pregnancies.

OBJECTIVE: Our purpose was to determine the accuracy of the summated amniotic fluid index designed to estimate the total amniotic fluid volume in twin pregnancies. STUDY DESIGN: The summated amniotic fluid index was measured in 62 normal diamniotic twin pregnancies by adding the deepest vertical pockets in the four quadrants. Actual amniotic fluid volume was then determined in all 124 amniotic sacs by amniocentesis and a dye-dilution technique. For data analysis, amniotic fluid volumes were classified by percentile with use of previously reported norms. RESULTS: There were significant differences in the percentile distribution of amniotic fluid volume as estimated by the summated amniotic fluid index and the actual volume as determined by dye dilution (p < 0.001). The summated amniotic fluid index has a sensitivity of only 13% in predicting amniotic sac volume. CONCLUSION: The summated amniotic fluid index is a poor predictor of intertwin differences in amniotic fluid volume and cannot identify twin pairs at risk for oligohydramnios and hydramnios.

Adult↗
PubMed1997

Ultrasonographic assessment of amniotic fluid does not reflect actual amniotic fluid volume.

OBJECTIVE: Our objective was to compare the ability of two methods of amniotic fluid assessment (two-diameter amniotic fluid pocket versus the amniotic fluid index) to predict oligohydramnios (actual amniotic fluid volume < 500 ml) or polyhydramnios (actual amniotic fluid volume > 1500 ml). STUDY DESIGN: The amniotic fluid index and the two-diameter amniotic fluid pocket were assessed before amniocentesis and determination of amniotic fluid volume with the dye (aminohippurate sodium)-dilution technique. To assess the detection of either oligohydramnios or polyhydramnios, the areas under the receiver-operator characteristic curves (+/-SE) were estimated by the point-to-point trapezoidal method of integration. Prediction limits were calculated by regression analysis of amniotic fluid index or two-diameter amniotic fluid pocket versus actual amniotic fluid volume and determination of 95th percentile ranges for amniotic fluid volume. RESULTS: We studied 144 patients with a mean (+/-SD) gestational age of 31.7 +/- 5.5 weeks; mean (+/-SD) amniotic fluid index and two-diameter amniotic fluid pocket were 12.6 +/- 6.1 cm and 21.2 +/- 18.4 cm2, respectively. Mean (+/-SD) actual amniotic fluid volume was 722 +/- 735 ml (range 101 to 4318 ml). The areas under the four receiver-operator characteristic curves were not significantly different from the nondiagnostic line (p < 0.05). Regression slopes (r values) for amniotic fluid index and two-diameter amniotic fluid pocket versus actual amniotic fluid volume were 0.34 and 0.23, respectively. Calculation of the prediction limit for 95% confidence that oligohydramnios is absent requires that the amniotic fluid index be 30 cm and the two-dimension amniotic fluid pocket be 90 cm2, both thresholds of which are currently considered to represent clinical polyhdramnios. CONCLUSIONS: Both amniotic fluid index and two-dimension amniotic fluid pocket appear to be inaccurate predictors of actual oligohydramnios or polyhydramnios when compared with dye-dilution calculations of actual amniotic fluid volume.

Adult↗
PubMed1997

Intrapartum oligohydramnios does not predict adverse peripartum outcome among high-risk parturients.

OBJECTIVE: Oligohydramnios can be defined by an amniotic fluid index < 5th percentile for gestational age or an amniotic fluid index < or = 5.0 cm regardless of gestational age. The purpose of this prospective study was to determine whether oligohydramnios by either definition predicts accurately, in a high-risk population, the risks for cesarean section for fetal distress, Apgar score < 7 at 5 minutes, and neonatal acidosis. STUDY DESIGN: An amniotic fluid index was obtained in 490 consecutive parturients with medical or obstetric complications and a reliable gestational age. After each delivery, an umbilical arterial blood gas analysis was obtained. Both measures of amniotic fluid index were rated as screening tests with use of sensitivity, specificity, predictive values, and receiver-operator characteristic curves. RESULTS: The incidences of cesarean section for fetal distress and umbilical arterial pH < 7.00 were 14% and 1.8%, respectively. The 70 neonates delivered by cesarean section for distress, compared with the 420 without, had a significantly higher incidence of pH < 7.00 (8.5% vs 0.7%, p = 0.0004, relative risk 5.0, 95% confidence interval 2.9 to 8.4). Sensitivity and positive predictive values of an amniotic fluid index < 5th percentile for gestational age to predict pH < 7.00 were 0.8% and 22%, respectively, and for an amniotic fluid index < or = 5.0 cm, 0.5% and 11%, respectively. Receiver-operator characteristic curves indicate that an amniotic fluid index between 0 and 20 cm cannot predict accurately which parturients will have cesarean sections for distress or be delivered of a newborn with a low Apgar score at 5 minutes or a pH < 7.10. CONCLUSION: Both criteria for oligohydramnios are poor predictors of adverse outcome for high-risk intrapartum patients.

Adolescent↗
PubMed1997

Sonographic examination does not predict twin growth discordance accurately.

OBJECTIVE: To assess the accuracy of estimating birth weight among twins with discordancy (intra-pair difference in actual birth weight of more than 25%) and to determine the relative accuracy of an intra-pair difference in abdominal circumference (delta AC) of 20 mm or more or in estimated fetal weight (delta EFW) of 25% or more for the identification of discordant growth in twins. METHODS: Over a 6-year period, we identified all non-anomalous twin pairs with gestational ages greater than 23 weeks and sonographic examinations within 3 weeks of birth. Ultrasonographic biometry of both twins included AC, head circumference, and femur length; these indices were used to estimate fetal weight by Hadlock's formula. Likelihood ratios, receiver-operating characteristic curves, and prediction limits were applied to assess the accuracy of the two diagnostic methods to predict an abnormal outcome. RESULTS: A total of 242 twin pairs were studied. The mean gestational age among the 21 twins with abnormal growth (30.6 +/- 4.6 weeks) was significantly less than among the 221 twins with normal growth (33.2 +/- 4.0 weeks) (P < .005). The biometric measurements of fetal parts, sonographic estimate of fetal weight, and actual birth weight for both fetuses were significantly less for discordant twin pairs (P < .05). The accuracy of predicting birth weight, as determined by mean error and percentage of the estimate within 10% of the actual weight, was similar between the groups. Receiver-operating characteristic curves showed that both diagnostic tests yielded areas under the two curves not significantly different from the area under the nondiagnostic line (P > .05). Most important, prediction limit calculations indicated that a 90% certainty that the actual birth weight discordance was at least 25% was achievable only if delta AC was 172 mm or greater or delta EFW was 112% or more. CONCLUSION: The most popular current methods (difference in AC or EFW) for predicting discordant growth in twin gestations have limited accuracy when held to a standard for discordance that requires a birth weight difference of at least 25%.

Birth Weight↗
PubMed1997

Amniotic fluid volume in normal singleton pregnancies.

OBJECTIVE: To evaluate the amniotic fluid (AF) volume in normal singleton pregnancies from 15 to 40 weeks. METHODS: This prospective study evaluated the AF volume in singleton pregnancies undergoing amniocentesis for genetic assessment of fetal karyotype, preterm labor, or fetal lung maturity. Amniotic fluid volume was determined using a dye dilution technique. To assess the relationship between AF volume and estimated gestational age, a nonlinear regression model was applied. RESULTS: One hundred forty-four normal singleton pregnancies had AF volume evaluated. There was wide variability in the measured AF volumes with a significant (P < .01) increase in AF volume as a function of gestational age. Growth curve modeling estimated that AF volume continued to increase until 40 weeks' gestation. Analyses of the observed AF volume indicated that AF volume nearly doubled after 30 weeks' gestation. CONCLUSION: In contrast to other reports indicating that maximal AF volume in singleton gestations is expected early in the third trimester, we observed the attainment of maximal AF volume near term.

Adult↗
PubMed1997

Remote umbilical arterial blood pH analysis: accuracy, utility, and limitations.

It is not always possible or feasible to perform routine umbilical artery blood sampling at birth. This study was undertaken to assess the accuracy of selective remote umbilical arterial blood analysis to retrospectively predict the original birth pH of any newborn. Umbilical arterial blood samples were obtained in two preheparinized syringes immediately following 1007 deliveries. One sample was analyzed within 60 minutes of delivery. The other was placed on ice and later analyzed at variable time intervals up to 180 hours postpartum. The results of each remote analysis were adjusted using a previously published regression equation to accurately identify which newborns had pH values < 7.00, < or = 7.10, or < 7.20 at birth. Among the 1007 newborns, there were 14 (1.3%), 44 (4.3%), and 187 (18.5%) who had pH values < 7.00, < or = 7.10, and < 7.20, respectively, at birth. Remote umbilical arterial samples analyzed within 72 hours of delivery correctly identified newborns with an original pH < 7.00, < or = 7.10, or < 7.20 with: (1) a sensitivity of 100, 82, and 84%, respectively; (2) positive predictive values of 100, 93, and 66%, respectively; and (3) a test efficiency of 100, 99, and 89%, respectively. Up to 72 hours after delivery, remote umbilical arterial blood pH analysis can be reliably used to accurately identify the newborn that was acidotic at birth.

Acidosis↗
PubMed1997

Cesarean section for suspected fetal distress. Does the decision-incision time make a difference?

OBJECTIVE: To compare perinatal outcomes in patients at term (37 weeks) in whom the decision-incision time for cesarean delivery was due to suspected fetal distress. STUDY DESIGN: All parturients who underwent cesarean delivery primarily for possible fetal distress during a three-year period were identified retrospectively. Student's t test and the chi 2 test were utilized, and P < .05 was considered significant. A regression analysis of decision-incision time and umbilical arterial pH was performed. RESULTS: From 1991 to 1993, 1.3% (117/9,137) of term laboring patients underwent emergency cesarean delivery for the primary indication of possible fetal distress. In 61 patients (52%) the decision-incision time was 30 minutes, while it exceeded 30 minutes in the remaining 56 women. The two patient groups were similar in maternal demographics, antepartum complications, oxytocin usage, thick meconium, type of abnormal fetal heart rate tracing prompting surgery, use of amnioinfusion (41% vs. 36%), general anesthesia (97% vs. 93%), mean birth weight and Apgar score < 7 at five minutes. Three adverse outcomes were observed more frequently in association with decision-incision time > 30 minutes: (1) lower mean (+/-SD) umbilical arterial pH (7.16 +/- 0.15 vs. 7.26 +/- 0.06, P = .001), (2) pH < 7.00 (8/61 vs. 0/56, P = .005), and (3) admission to the neonatal intensive care unit (P = .008). When the incision was made longer than 30 minutes after the decision, there was no apparent adverse neonatal or infant outcome. CONCLUSION: Although a cesarean decision-incision time < or = 30 minutes is a desirable goal for the fetus possibly in distress, failure to achieve this goal is not associated with a measurable negative impact on newborn outcome.

Adult↗
PubMed1996

Military pregnancies and adverse perinatal outcome.

OBJECTIVE: To identify significant risk factors for an adverse outcome in active-duty military women. METHODS: A prospective study of 105 pregnancies and their outcome. RESULTS: The data revealed that: (1) single women more than married personnel had cesarean births when compared with forceps and vacuum (P < 0.03) or spontaneous vaginal delivery (P < 0.04); and (2) active-duty women who gained < 25 pounds during pregnancy developed preterm labor more often (P < 0.05). CONCLUSIONS: Risk factors for these adverse outcomes remain unknown.

Adult↗
PubMed1996

Employment, exertion, and pregnancy outcome: assessment by kilocalories expended each day.

OBJECTIVE: Our purpose was to evaluate the influence of employment and physical exertion on pregnancy outcome as quantified by kilocalories expended each day. STUDY DESIGN: This prospective study assessed 2743 pregnant women who received prenatal care and were delivered at the major perinatal center in Western Australia between May 1989 and November 1991. All women completed an extensive questionnaire on their social, medical, psychosocial, and economic circumstances. The women were allocated to five groups on the basis of kilocalorie expenditure per day. RESULTS: The characteristics of women in each energy expenditure group were different, with those in the least-expenditure group being younger and shorter, more likely to be living in worse socioeconomic conditions, smoke cigarettes, be nulliparous, and to be of an ethnic group other than white. After confounding effects were adjusted, women in the medium energy expenditure group were delivered of babies of higher birth weight than were women in other groups. However, the differences in birth weight between the energy expenditure categories were small, and mean birth weights within each group were within the normal range. Women in the medium energy expenditure group also had fewer incidences of prelabor rupture of membranes and women in the lower energy expenditure category had increased risks of antepartum admission to the hospital and preterm birth. A variety of other differences were observed in pregnancy outcomes for women in each of the categories of energy expenditure, but most of these differences were explained by the characteristics of the women in each expenditure level rather than the exercise pattern itself. CONCLUSION: These results indicate that the effects of daily energy expenditure on pregnancy outcome are not great. Enthusiasm for counseling pregnant women of the benefits or hazards of extremes in daily activity should be tempered by the relative lack of an effect and the fact that most apparent differences are due to confounding variables rather than the exercise itself.

Adult↗
PubMed1996

Estimating birth weight in twins. Comparison of eight sonographic models.

OBJECTIVE: To establish the relative accuracy of eight sonographic models that use one to four fetal biometric measurements to derive birth weight in twin pregnancies. STUDY DESIGN: Over three years, 181 twin gestations with sonographic mensuration of biparietal diameter, head circumference, abdominal circumference (AC) and femur length (FL) within 96 hours of delivery were analyzed. Analysis of variance followed by Student-Newman-Keul's test was used to determine the relative accuracy of the eight models. A receiver-operating characteristic (ROC) curve was constructed to determine the sonographic estimate that would consistently identify a nonvertex twin B with a birth weight of < or = 1,500 g. RESULTS: The mean gestational age was 32.4 +/- 4.3 (SD) weeks, and the mean birth weights for twins A and B were 1,851 +/- 676 and 1,883 +/- 655 g, respectively. For both fetuses, the mean standardized absolute error was significantly higher for estimates based on one fetal parameter (AC or FL). Regardless of presentation (A or B, vertex or nonvertex) or whether the actual birth weight was < or = 1,500 or > 1,500 g, accuracy was similar between the six models that used two or more fetal parameters to predict the newborn's weight. ROC analysis revealed that among nonvertex twins B, an estimate of birth weight (based on BPD and AC or AC and FL) < or = 1,700 g will consistently identify the newborn with a birth weight < or = 1,500 g. CONCLUSION: Sonographic models that use two fetal parameters are adequate for assessing birth weight in twin gestations regardless of position or if the birth weight is < or = or > 1,500 g.

Adult↗