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Biomedical subjects

L H Nelson

Publications and source records attributed to L H Nelson.

At least 19 recordsLinked to original sources
PubMed1996

The role of antepartum surveillance in the management of gastroschisis.

OBJECTIVE: To evaluate the perinatal morbidity and mortality of fetuses diagnosed with gastroschisis at our Fetal Diagnosis and Treatment Center. METHODS: A retrospective review of a regional prenatal diagnostic center. Twenty-nine cases of gastroschisis which were diagnosed, managed, delivered and had corrective surgeries through the Fetal Diagnosis and Treatment Center were identified from 1985 to 1994. Perinatal morbidity and mortality were reviewed. Antepartum testing schemes were reviewed when available to determine whether morbidity or mortality could have potentially been prevented. RESULTS: Meconium occurrence, intrauterine growth retardation (IUGR) and oligohydramnios complicated 79%, 41% and 36% of the cases, respectively. The perinatal mortality of this series was 241/1000. Significant differences in perinatal mortality were noted when fetal testing was incorporated (200/1000 vs. 286/1000, P < or = 0.001). CONCLUSION: Gastroschisis is associated with a high incidence of IUGR, meconium, oligohydramnios and high perinatal mortality. Antenatal testing appears to significantly lower perinatal mortality in pregnancies complicated by gastroschisis.

Abdominal Muscles↗
PubMed1996

Diet composition related to body fat in a multivariate study of 203 men.

OBJECTIVE: To assess whether usual diet (especially intake of dietary fat, carbohydrate, and fiber) was related to body fat percentage in healthy men. DESIGN: A written questionnaire provided data on demographic and lifestyle characteristics. Dietary fat, carbohydrate, protein, and fiber intakes were analyzed using the National Cancer Institute food frequency questionnaire. Percentage of body fat was determined using three-site skinfold measurements, and a submaximal treadmill test was used to estimate aerobic fitness. SUBJECTS: Subjects were 203 healthy men (14.0 +/- 5.3% mean body fat) aged 21 to 71 years. The subjects were chosen from randomly selected districts within Utah County and volunteered for free diet and fitness evaluations. STATISTICAL ANALYSIS: Multiple regression analysis determined the extent to which the individual diet components predicted body composition before and after controlling for energy intake, fitness level, body weight, and age. Multivariate analysis of variance was used to compare relative body fat groups in regard to dietary variables. RESULTS: Reported intakes of carbohydrate (P = .0085, R2 = .022), complex carbohydrate (P = .0127, R2 = .024), and fiber (P = .002, R2 = .03) were inversely associated with body fat after controlling for age, energy intake, and fitness level. Energy intake was positively related to body fat after controlling for age, fitness level, and body weight. When subjects were separated into low-, moderate-, and high-body-fat groups, the fattest subjects reported eating significantly more dietary fat (P = .05) and less carbohydrate (P = .01), complex carbohydrate (P = .01), and fiber (P = .005) than the leanest subjects. No significant difference in reported energy intake was noted across body fat groups. APPLICATIONS: Composition of the diet may play a role in obesity beyond energy intake in men over the long-term. Lifestyle changes for men should probably include modifications in diet composition, especially increased consumption of foods high in complex carbohydrate and fiber.

Adipose Tissue↗
PubMed1996

Prenatal diagnosis and pediatric neurosurgery.

Advances in realtime ultrasound imaging and a greater availability of high-quality ultrasound equipment have resulted in an increased number of congenital abnormalities being diagnosed prenatally in the last 10-15 years. In addition, testing for maternal serum alpha-fetoprotein, beta-human chorionic gonadotropin, and serum unconjugated estriol has allowed for more sensitive screening for congenital abnormalities. In response to this, in 1989 the Prenatal Diagnosis and Treatment Center was established at our institution to coordinate the care of fetuses and newborns with congenital malformations and to provide alternatives for the parents should the fetus not be carried to term. From January 1990 through June 1993, our group diagnosed 50 singleton pregnancies with various types of central nervous system disorders by the methods outlined above. Thirty-seven fetuses were diagnosed with neural tube defects. Of these, 5 were anencephalic and 1 had an encephalocele. The remaining 31 fetuses had meningomyeloceles with associated hydrocephalus. Of these 31, 18 fetuses were terminated prior to the age of viability as a result of our counseling and 13 fetuses were brought to term. Of the remaining 13 fetuses, 8 had hydrocephalus and 5 had various other diagnoses. Three of the eight hydrocephalic fetuses were either terminated, stillborn, or died following birth. Of the other 5 fetuses with hydrocephalus, 3 had shunts placed, 1 was followed with normal head growth, and 1 had normal ventricular size at birth. Using the methods available, the accuracy of diagnosis is very high, with only 1 fetus in this series being incorrectly diagnosed. Additionally the advantages of being able to counsel the parents regarding their unborn child allows them to make informed decisions. Accurate prenatal diagnosis plays a major role in the care of the fetus and in counseling parents prenatally for pediatric neurosurgical problems.

Abnormalities, Multiple↗
PubMed1994

Expectant management of preterm premature rupture of the membranes.

OBJECTIVES: Our purpose was to (1) evaluate expectant management of preterm premature rupture of the membranes between 20 and < 36 weeks' gestation and (2) compare outcomes in service and private populations. STUDY DESIGN: The study included only singleton pregnancies prospectively managed between 20 and < 36 weeks' gestation with proved preterm premature rupture of the membranes. None of the patients received prophylactic antibiotics, tocolytics, or steroids, and none of the neonates received surfactant or had lethal anomalies. Patients (n = 511) were divided into private (n = 194) and staff (n = 317) categories, but all were managed identically. RESULTS: Approximately 50% of patients were delivered within 48 hours. Infection is more likely with preterm premature rupture of membranes before 28 weeks' gestation (p = 0.001), as is fetal death associated with infection (p < 0.001). Other findings in this study were (1) no significant differences in evaluated outcomes between private and staff patients, except that significantly more vaginal deliveries occurred in staff patients, (2) a prolongation of pregnancy > or = 7 days in 12.9% of patients, (3) a significant increase in the rate of maternal infection if preterm rupture of membranes occurred before 28 weeks' gestation, (4) a significant increase in fetal and neonatal deaths if preterm premature rupture of membranes occurred before 28 weeks, and (5) an increased probability of survival whose rate of increase is dependent on the gestational age at which preterm premature rupture of membranes occurred. For babies weighing < 1500 gm at birth compared with controls, babies delivered of mothers not having preterm premature rupture of membranes, 1-year follow-up revealed (1) a significantly lower incidence of pulmonary interstitial emphysema and cerebral palsy in the study group delivered before 28 weeks' gestation, (2) a significantly lower incidence in bronchopulmonary dysplasia in the study group delivered after 28 weeks' gestation, and (3) no significant differences in the incidence of intraventricular hemorrhage, pneumothorax, or Bayley Mental Developmental Index < 68 between those delivered before or after 28 weeks' gestation. CONCLUSION: Over 47.8% of the patients continued their pregnancy beyond 48 hours, and in 12.9% of cases expectant management of preterm premature rupture of membranes prolonged the pregnancy by > or = 7 days. The maternal infection rate is greater before 28 weeks' gestation and is associated with higher fetal-neonatal mortality. Status has little impact on outcome. Expectant management is not detrimental to quality of survival. Survival probability increases at a more rapid rate with preterm premature rupture of membranes after 22 weeks of gestation.

Adult↗
PubMed1993

Obstetric and anesthetic considerations in the May-Hegglin anomaly. A case report.

The obstetric and anesthetic considerations in the management of a patient with the May-Hegglin anomaly, an autosomal dominant platelet deficiency, are discussed. A review of the medical literature notes three previous case reports of May-Hegglin anomaly in pregnancy. In addition to the two successful pregnancies reported in this paper, there are four infant survivors among the five reported pregnancies. Anesthetic managements included general and spinal anesthesia: the latter employed following platelet transfusion. A successful pregnancy should be anticipated when management includes a well-informed patient and coordinated obstetric and anesthetic care.

Adult↗
PubMed1991

First report of management and outcome of pregnancies associated with hereditary orotic aciduria.

Two pregnancies in a 25-year-old woman with hereditary orotic aciduria who was managed prenatally on uridine therapy are described. The first pregnancy resulted in an infant with multiple congenital anomalies and a 47,xx,inv(4)(p12q25), +der(22)t(11;22)(p23;q11) karyotype. The proposita was found to be a carrier of a de novo 11;22 translocation and a pericentric inversion of chromosome 4. Subsequently, several carriers of orotic aciduria in this family were identified with the inverted chromosome 4. The second pregnancy resulted in a normal male with an inverted chromosome 4.

Abnormalities, Multiple↗
PubMed1991

Introduction to transvaginal imaging.

Transvaginal sonography provides improved resolution and avoidance of intervening anatomic structures that can degrade the image. In this article, transvaginal transducers are described and compared with transabdominal transducers. The sagittal and coronal views used in transvaginal sonography are described. Advantages and disadvantages of transvaginal sonography are considered. Safety considerations of the decreased attenuation path to the fetus are dealt with.

Abdomen↗
PubMed1990

Uterine and umbilical artery flow velocity waveform analysis in pregnancies complicated by chronic hypertension or preeclampsia.

Using continuous wave Doppler ultrasound, we studied the umbilical and uterine flow velocity waveforms in 68 pregnant women who had chronic hypertension and/or preeclampsia. The systolic-diastolic (S/D) ratio was considered an expression of vascular resistance peripheral to the point of insonation. Abnormal umbilical artery S/D ratio (greater than 95th percentile) alone or with abnormal uterine artery S/D ratio was associated with poor pregnancy outcome as judged by incidence of intrauterine growth retardation (IUGR), cesarean section rate, birth weight, perinatal morbidity and mortality, and prematurity. In patients with preeclampsia and abnormal Doppler values, pregnancy outcome was poor, whereas in those with normal Doppler values, pregnancy outcome approached normal. The same relationship was also found in patients with chronic hypertension. The sensitivity and specificity for the prediction of IUGR by the umbilical artery S/D ratio alone was 71% and 93%, respectively. The uterine artery S/D ratio alone yielded a 66% sensitivity and 64% specificity, and when both tests were taken into account, the sensitivity increased to 75% and the specificity to 100%. Abnormal umbilical and uterine artery S/D ratios were associated with 100% IUGR and 25% perinatal mortality. We conclude that in pregnant women with hypertensive disorders there is a significant difference in pregnancy outcome between those with normal and those with abnormal Doppler values. Umbilical artery S/D ratio alone is a better predictor of IUGR and poor pregnancy outcome than the uterine artery S/D ratio.

Blood Flow Velocity↗
PubMed1990

Diagnosis of vasa previa with transvaginal and color flow Doppler ultrasound.

Vasa previa, which is associated with high fetal mortality, is present when fetal vessels cross the internal cervical os as a velamentous insertion of the umbilical cord with or without a succenturiate lobe or bilobate placenta. This is the first case report of vasa previa not associated with a succenturiate lobe or bilobate placenta and in which the diagnosis was made using a combination of transvaginal ultrasonography and color flow Doppler ultrasound. The infant was delivered by elective cesarean, and the ultrasound findings were confirmed. Color flow Doppler and transvaginal ultrasound facilitate this diagnosis because the internal os and surrounding structures are easier to visualize; in addition, vascular flow and Doppler patterns characteristic of the umbilical cord can be demonstrated in structures suspected to be vessels.

Adult↗
PubMed1989

Correcting umbilical artery flow velocity waveforms for fetal heart rate is unnecessary.

We prospectively examined 55 normal pregnant women between 32 and 41 (means = 37) weeks' gestation. Five measurements of the umbilical artery peak-systolic/end-diastolic frequency ratio were obtained from each patient during one examination. Comparison of the fetal heart rate and the umbilical artery peak-systolic/end-diastolic frequency ratios between pregnancies less than 37 and greater than 37 weeks' gestation revealed no difference. Subsequently a total of 256 measurements were analyzed as one group. Plotting the individual peak-systolic/end-diastolic frequency ratios against the corresponding fetal heart rates revealed a moderate negative linear correlation: y = 4.15-0.012x, r = -0.36 and p less than 0.04. When only heart rates between 120 to 160 beats/min were plotted against peak-systolic/end-diastolic frequency ratios, a weaker correlation was found (r = -0.33, p = 0.15). The difference (mean +/- SD) between the obtained and the corrected peak-systolic/end-diastolic frequency ratios was 4.4% +/- 3.2%. The 95th percentile of the obtained peak-systolic/end-diastolic frequency ratio was 3.35 and the corrected ratio was 3.27. Averaging of the five measurements obtained from each patient for all 55 patients decreased the 95th percentile value to 3.09 whereas the same procedure for the corrected peak-systolic/end-diastolic frequency ratios decreased it to 3.07. We conclude that although there is a statistically significant negative linear correlation between the fetal heart rate and the umbilical artery peak-systolic/end-diastolic frequency ratio, this relationship is not clinically significant.

Arteries↗
PubMed1989

False-positive acetylcholinesterase with early amniocentesis.

Among 93 acetylcholinesterase determinations performed on amniotic fluid samples from pregnancies at 11-14 weeks' gestation, five unexplained false-positive results were observed. In four of the five cases, the ratio of acetylcholinesterase to pseudocholinesterase was compatible with that observed in association with open neural tube defects in later gestation. In contrast, no false-positive results were noted among 951 acetylcholinesterase determinations performed on samples from women at 15-20 weeks' gestation. Repeat amniocentesis was performed several weeks after the first procedure in four of the five cases of early amniocentesis and false-positive results; in each case, the acetylcholinesterase was negative on the second sample. All four pregnancies had a normal outcome. In the remaining case, trisomy 21 was diagnosed in the fetus and the pregnancy was terminated. Positive acetylcholinesterase results should be interpreted cautiously in samples from early amniocentesis, especially when the amniotic fluid alpha-fetoprotein level is not markedly elevated. The acetylcholinesterase-to-pseudocholinesterase ratio is not useful in identifying fetal neural tube defects before 15 weeks' gestation. Repeat amniocentesis may help in determining the significance of a positive acetylcholinesterase result from early amniocentesis when no fetal defect is identified by ultrasonography.

Acetylcholinesterase↗
PubMed1988

The effect of placental location on uterine artery flow velocity waveforms.

We examined the effect of placental location with regard to flow velocity waveforms in the uterine arteries in 84 control and 28 hypertensive women during the third trimester of pregnancy. The ratio of systolic peak to end-diastolic frequency was obtained with a continuous-wave Doppler device and the placental location was determined by real-time ultrasonography. In both normal and hypertensive pregnancies with unilateral placental location the systolic/diastolic ratio of the ipsilateral uterine artery was significantly lower than the contralateral artery ratio [1.73 +/- 0.35 (systolic/diastolic ratio) versus 2.46 +/- 0.73, p less than 0.001, and 2.38 +/- 1.01 versus 4.04 +/- 1.77, p = 0.0012, respectively]. The physiologic and clinical significance of this finding is discussed.

Arteries↗
PubMed1987

C-reactive protein: a limited test for managing patients with preterm labor or preterm rupture of membranes?

C-reactive protein has been used to identify patients at high risk for infectious morbidity with preterm labor or preterm rupture of membranes. In this article we report on 104 patients with preterm labor symptoms (n = 45) or preterm rupture of the membranes (n = 59) and serial evaluations of C-reactive protein measured by latex agglutination and laser nephelometry. The simple, inexpensive latex method appears comparable to the laser method in predicting infectious morbidity and can be used clinically. Elevated C-reactive protein values before delivery predict infectious morbidity in only 8% to 29% of patients, and up to 18% of patients with serious infections may be misdiagnosed as having normal C-reactive protein values before delivery.

C-Reactive Protein↗