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Biomedical subjects

T R Moore

Publications and source records attributed to T R Moore.

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

Pregnancy outcome in military and civilian women.

Physical and medical risk factors have long been linked to prematurity and intrauterine growth retardation. Recently, out-of-home employment has been cited as an additional risk. The primary objective of this investigation was to compare pregnancy risks and birth outcome in two groups of employed women (one military and one civilian). We performed a prenatal survey and a postpartum chart review and found that active duty military women worked longer into pregnancy and reported lower levels of social support than their civilian counterparts. However, infant weight and gestational age were not significantly different in the two groups.

Adult↗
PubMed1993

Hemodynamic and fluid responses to furosemide infusion in the ovine fetus.

OBJECTIVES: The direct effects of furosemide infusion have not been systematically examined in the fetus. Our objective was to explore the hemodynamic and urinary responses to a 4-hour infusion of furosemide into fetal sheep. STUDY DESIGN: Furosemide (0, 1, 5, or 10 mg/hr) was infused into the fetal inferior vena cava for 4 hours in 15 chronically catheterized near-term sheep. RESULTS: Relative to vehicle infusion, furosemide produced dose-dependent increases in fetal arterial pressure (analysis of variance, p < 0.05 when comparing groups), fetal heart rate (p < 0.0001), urine flow (p < 0.0001), and urine osmolality, sodium, and chloride, concentrations (p < 0.0001). Concomitantly, there were dose-dependent decreases in fetoplacental blood volume, fetal plasma chloride (p < 0.0001) and fetal venous pressure (p < 0.05). The changes in urine flow rate and fetal arterial pressure were positively correlated (r = 0.46, p < 0.01), suggesting that the diuresis was mediated in part by fetal arterial pressure. The four-quadrant amniotic fluid index increased during the furosemide infusions but not during vehicle infusions (p = 0.022). CONCLUSIONS: Furosemide infusion caused a marked dose-dependent diuresis in the ovine fetus that appears to be partly mediated by increases in vascular pressure. Although amniotic fluid volume increases and fetal blood volume decreases, the reduction in blood volume was small compared with the urine volume excreted.

Amniotic Fluid↗
PubMed1993

The prognostic value of hemoglobin A1c in predicting fetal heart disease in diabetic pregnancies.

OBJECTIVE: To evaluate detailed fetal echocardiography for predicting congenital heart disease in overt diabetic pregnancies. METHODS: Overt diabetic gravidas with initial hemoglobin A1c (HbA1c) at or above 8.5%, a family history of congenital heart disease, or fetal cardiac anomaly suspected on screening sonography were referred to a pediatric cardiologist for detailed fetal echocardiography. After 7 years, the results of the protocol were reviewed retrospectively. The sensitivity and specificity of the initial HbA1c in predicting congenital heart disease were assessed. RESULTS: During the study period, 193 patients received care in the diabetes and pregnancy service. Sixty-four received fetal echocardiography, 47 because of initial HbA1c levels at or above 8.5% and 17 for other indications. Twenty fetuses had major anomalies, eight of which were cardiac (40%). Six of the cardiac anomalies had been studied by fetal echocardiography, and four were diagnosed correctly. The initial HbA1c was not different among pregnancies with major anomalies, cardiac anomalies, or no anomalies. No malformations were noted in patients with normal initial HbA1c values. The overall sensitivity of the protocol for identifying congenital heart disease was 50% (four of eight) and specificity was 54% (90 of 167). Detailed fetal echocardiography had a sensitivity of 66% (four of six) and a specificity of 100% (58 of 58) for correctly identifying fetal congenital heart disease. CONCLUSIONS: No cases of congenital heart disease were observed in patients with a normal initial HbA1c value. Among patients with abnormal HbA1c values, no critical level of glycohemoglobin was identified that provided optimal predictive power for congenital heart disease screening. We recommend detailed fetal echocardiographic imaging in all patients with initial HbA1c levels above the upper limit of normal of 6.1%.

Diabetes Mellitus, Type 1↗
PubMed1992

Angiographic embolization in the management of hemorrhagic complications of pregnancy.

Obstetric hemorrhage continues to be a major cause of maternal mortality and morbidity. Recent developments in percutaneous angiographic embolization techniques have afforded the ability to control persistent bleeding from pelvic vessels while avoiding the morbidity of surgical exploration. We report the use of angiographic embolization in 10 cases of pregnancy-related hemorrhage, including persistent postcesarean bleeding (three cases), vaginal wall hematomas (four cases), cervical ectopic pregnancies (two cases), and postpartum bleeding as a secondary complication of uterine myomas (one case). The embolization procedures were successful in all cases. Nine of 10 patients experienced postprocedural fever with eight cases resolving with antibiotic therapy alone and one patient requiring vaginal drainage of the hematoma-abscess. The mean length of time for the procedure was 167 minutes (range 70 to 270). The average length of hospitalization was 8 days (range 2 to 13). These data indicate that angiographic embolization is effective in treating hemorrhagic complications of pregnancy in hemodynamically stable patients and is preferable to surgery in selected cases.

Angiography↗
PubMed1992

Indomethacin-induced urinary flow rate reduction in the ovine fetus is associated with reduced free water clearance and elevated plasma arginine vasopressin levels.

OBJECTIVE: The purpose of our study was to explore the urinary responses of the ovine fetus to indomethacin levels comparable with those used therapeutically in the human fetus. STUDY DESIGN: After a 1-hour control period, chronically catheterized ovine fetuses between 125 and 139 days of gestation were given an intravenous bolus of indomethacin (0.05 mg/kg estimated fetal weight) followed by a 0.0025 mg/kg/min continuous infusion for 5 hours. The experimental group (n = 9) was compared with a vehicle-only infusion group (n = 10). RESULTS: There was a sustained 55.7% +/- 9.5% (mean +/- SEM) decrease in urinary output by 2 hours of indomethacin infusion (p < 0.00001, analysis of variance). Urinary osmolality, potassium, and chloride concentrations underwent sustained increases during the infusion period (p < 0.005). Free water clearance decreased by 67.5% +/- 12.0% (p < 0.001). Fetal arterial pressure increased only transiently (p < 0.05), and increases in venous pressure (p = 0.013) and heart rate (p < 0.0001) were sustained. Fetal plasma arginine vasopressin concentration increased during indomethacin infusion (p < 0.05) and was correlated with the fall in urinary flow rate and free water clearance (p = 0.002). During vehicle infusion no significant changes were observed in any of the variables. CONCLUSIONS: Our data indicate that the fetus undergoes antidiuresis when exposed to low levels of indomethacin and that the observed antidiuresis is mediated by a decrease in free water clearance. The reduction in free water clearance may be mediated by increases in plasma arginine vasopressin concentrations.

Animals↗
PubMed1992

Urinary and cardiovascular responses to indomethacin infusion in the ovine fetus.

OBJECTIVE: Our objective was to explore the urinary and cardiovascular responses of the near-term ovine fetus to plasma indomethacin levels similar to those in the human neonate undergoing indomethacin therapy. STUDY DESIGN: Chronically catheterized ovine fetuses between 125 and 139 days of gestation were studied. After a 1-hour control period we gave a bolus of 0.35 mg/kg estimated fetal weight of indomethacin into a fetal vein, followed by a 0.017 mg/kg/min continuous infusion for 5 hours (n = 9). Results were compared with a vehicle-infusion-only group (n = 10). RESULTS: During the first 3 hours of indomethacin infusion, fetal urinary output was increased by an average of 84.9% +/- 55.6% (analysis of variance, p less than 0.01). Urinary osmolality and sodium and chloride concentrations underwent sustained increases throughout the infusion period (p less than 0.001). Sodium excretion increased by 212% +/- 111% (p less than 0.05). Fetal arterial and venous pressures increased (p less than 0.001), and the change in urinary flow correlated positively with the change in arterial pressure (R = 0.55, p = 0.014). Fetal heart rate increased by 10% +/- 4% 1 hour after the bolus and remained elevated throughout the remainder of the infusion relative to vehicle-infused animals (p less than 0.001). Vehicle infusion had no effect on any fetal variable. CONCLUSIONS: This study does not support the hypothesis that indomethacin acutely reduces urinary flow rate in the late-gestation ovine fetus. Further, the observed urinary flow increases may be mediated in part by a pressure diuresis.

Animals↗
PubMed1991

Transplacental, amniotic, urinary, and fetal fluid dynamics during very-large-volume fetal intravenous infusions.

With rapid intravenous infusion of very large volumes of isotonic saline solutions into the fetus, the fluid could stay within the fetal body, thereby creating hydrops fetalis, be transferred into the amniotic fluid through the fetal kidneys, thereby creating polyhydramnios, or be transferred across the placenta into the maternal circulation. This study was designed to explore these possibilities. After a 1-hour control period, 10 near-term chronically catheterized ovine fetuses were infused intravenously with 4 L (greater than 100% of fetal weight) of either isotonic saline solution or lactated Ringer's solution over 4 hours. Fetal arterial pressure was significantly elevated by 7 mm Hg throughout the infusion (p less than 0.00001). Venous pressure underwent a transient rise (4.8 mm Hg) at 20 minutes of infusion and remained elevated (2.7 mm Hg) during the rest of the infusion (p less than 0.00001). Fetal urine flow increased by an average of 5.7 +/- 0.4 ml/min throughout the infusion (p less than 0.00001) and accounted for 34.1% +/- 2.6% of the infused volume. Estimated fetal extracellular fluid volume increased by 17.7% +/- 1.8% of the infused volume. Because fetal fluid retention, urine flow, and amniotic fluid volume changes accounted for only half of the infused fluid, the remainder of the infused volume must have crossed the placenta and entered the maternal circulation. Given the above changes in vascular pressures, this requires a filtration coefficient of the placenta 50 to 100 times the previously reported values. Thus we conclude that relatively small changes in fetal vascular pressures dramatically alter the filtration capacity of the ovine placenta and transplacental volume flow.

Amniotic Fluid↗
PubMed1991

Diurnal rhythms in fetal urine flow, vascular pressures, and heart rate in sheep.

Conflicting indirect data exist as to whether diurnal variations occur in fetal urine flow rate. In addition, the extent of diurnal rhythms in fetal venous pressure or arterial pressure is unknown, although 24-h rhythms do exist in fetal heart rate. In the present study, we used on-line computer techniques to continuously monitor these variables in chronically catheterized ovine fetuses. Fetal urine flow rate and vascular pressures were successfully recorded in 6 of 11 animals over a 24-h period on 21 days out of a total of 45 days of monitoring. We found highly significant diurnal variations in fetal urine flow rate (P less than 10(-6). Hourly means displayed a maximum at 2130 h and a minimum at 1330 h with a maximum amplitude of 28 +/- 5% of the 24-h mean. A secondary maximum (at 0630 h) and minimum (at 0330 h) of smaller amplitude also occurred. There were simultaneous and highly significant (P less than 0.0001) diurnal rhythms in fetal arterial pressure (+/- 2%), venous pressure (+/- 7%), and heart rate (+/- 5%). The maxima in arterial pressure and heart rate occurred within 1 h of the maximum in urine flow, while venous pressure changes were opposite those in arterial pressure. Hourly mean urine flow correlated significantly with arterial pressure but not venous pressure or heart rate, suggesting that the observed 24-h variations in fetal urine flow rate may be partially mediated by a pressure diuresis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

The amniotic fluid index in normal human pregnancy.

The four-quadrant sum of amniotic fluid pockets (amniotic fluid index) was studied prospectively in 791 normal pregnancies. Interobserver and intraobserver variation was 3.1% and 6.7%, respectively. Logarithmic transformations were used to establish the mean and 90% confidence intervals for the amniotic fluid index at each week of gestation. In term pregnancies, the boundaries of the amniotic fluid index were 115 mm (mean), 68 to 196 mm (5th to 95th percentiles). In postdates pregnancies greater than 42 weeks, the values were 108 mm (mean), 67 to 174 mm (5th to 95th percentiles), p less than 0.0001. However, the values for each week were statistically distinct, indicating the need to reference amniotic fluid index measurements to week-specific normative tables for accurate interpretation. This study provides normative data for the amniotic fluid index throughout pregnancy.

Amniotic Fluid↗
PubMed1990

Superiority of the four-quadrant sum over the single-deepest-pocket technique in ultrasonographic identification of abnormal amniotic fluid volumes.

Ultrasonographic estimation of amniotic fluid volume is an important adjunct to assessment of fetal well-being. However, no single method has emerged as most predictive. Many ultrasonographers use subjective or single-pocket guidelines in evaluation of amniotic fluid volume. We therefore assessed the ability of a maximum-vertical-pocket technique to identify patients with abnormal volumes of amniotic fluid. A total of 1168 patients was studied. Oligohydramnios (n = 76) was defined as an amniotic fluid index less than 5th percentile for gestational age (70 to 98 mm). Hydramnios (n = 51) was defined when the amniotic fluid index was greater than 95th percentile (185 to 249 mm). The ability of the maximum-vertical-pocket technique to identify cases with oligohydramnios by amniotic fluid index was poor: sensitivity was 42% and positive predictive value was 51%. Fifty-eight percent of cases with oligohydramnios by amniotic fluid index had "normal" values according to the single-pocket technique. The correlation coefficient between amniotic fluid index and maximum vertical pocket was 0.51, R2 = 24%. The correlation between the maximum vertical pocket and amniotic fluid index was somewhat better in cases of polyhydramnios (r = 0.79, R2 = 62%), but the sensitivity, positive predictive value, and false-negative rates were high as in oligohydramnios. These data suggest that the maximum-vertical-pocket technique has adequate specificity but is a poor screening tool. The results demonstrate that use of gestation-specific norms for the amniotic fluid index identifies abnormal amniotic fluid volumes more efficiently than the single-pocket technique.

Amniotic Fluid↗
PubMed1990

Perinatal outcome of forty-nine pregnancies complicated by acardiac twinning.

Acardiac twinning affects 1 in 100 monozygotic twin pregnancies and 1 in 35,000 pregnancies overall. The presence of an acadiac twin requires the normal (or "pump") twin to provide circulation for itself, as well as the acardiac sibling. In many cases the acardiac twin is almost equal to the normal twin. The principal perinatal problems associated with acardiac twinning are pump-twin congestive heart failure, maternal hydramnios, and preterm delivery. We reviewed the perinatal courses of 49 acardiac twin pregnancies to identify factors prognostic of favorable outcome. The overall perinatal mortality was 55%, primarily associated with prematurity. Mean (+/- SD) gestational age at delivery was 29 +/- 7.3 weeks, with a mean (+/- SD) normal twin weight of 1378 +/- 1047 gm. The acardiac weight averaged 651 +/- 571 gm. However, the occurrence of hydramnios, the occurrence of preterm labor, and perinatal outcome were strongly related to the ratio of the acardiac and pump-twin's weight. The mean overall ratio of the twin weights was 52% +/- 42%. However, the mean weight ratio for patients delivered before 34 weeks was 60% versus 29% (p less than 0.04). Preterm delivery was strongly associated with the development of hydramnios and congestive heart failure in the pump twin (p less than 0.01). If the twin-weight ratio was above 70% (25% of cases), the incidence of preterm delivery was 90%; hydramnios, 40%; and pump-twin congestive heart failure, 30% compared with 75%, 30%, and 10%, respectively, when the ratio was less (p less than 0.05). Regression of the weight of the acardiac twin against its longest dimension (L) resulted in this equation for prediction of acardiac weight: Weight (grams) = 1.2 L2-1.7L; r = 0.79, p less than 0.01. These data suggest that estimation of the relative weights in acardiac twins provides prognostic information regarding outcome. Poor outcome occurs with congestive heart failure and hydramnios in the normal twin. Use of the above data may assist in counseling patients and determining optimal management.

Adult↗
PubMed1989

A prospective evaluation of fetal movement screening to reduce the incidence of antepartum fetal death.

Fetal death is a tragedy for mother, family, and obstetrician. Recent reviews of fetal death indicate that nearly half occur in pregnancies that are not candidates for traditional antepartum testing. We conducted a prospective evaluation of the effectiveness of a fetal movement screening program in reducing the fetal mortality rate. During a 7-month control period, 2519 deliveries occurred, no formal fetal movement assessment was done, and the fetal mortality rate was 8.7 per 1000 births. A pilot study was conducted to validate a protocol in which the patient was instructed to record the elapsed time required to appreciate 10 fetal movements. The mean time interval was 20.9 +/- 18.1 minutes (mean +/- SD). Patients in whom 2 hours elapsed without 10 fetal movements (mean +/- 5 SD) were to report to the delivery unit for further evaluation. During the study period, 1864 patients were delivered of infants and the fetal mortality rate was 2.1 per 1000 (chi 2 = 6.8, p less than 0.01). During the study period the number of antepartum tests performed increased by 13%. Interventions for fetal compromise prompted by inadequate fetal activity tripled in the study period, resulting in a drop in fetal mortality among patients with decreased movement from 44 to 10 per 1000. We conclude that the count-to-10 fetal movement screening program is simple and effective in reducing the fetal mortality rate.

California↗
PubMed1989

The reliability and predictive value of an amniotic fluid scoring system in severe second-trimester oligohydramnios.

Sixty-two cases of oligohydramnios diagnosed by ultrasound between 13-28 weeks' gestation were reviewed. Three experienced ultrasonographers used a subjective scale to rate the oligohydramnios as mild, moderate, severe, or anhydramniotic. Interobserver reliability was excellent (intraclass correlation coefficient 0.81). The overall perinatal mortality rate was 43%, and the incidence of pulmonary hypoplasia was 33%. One-third had lethal congenital anomalies. The frequency of adverse outcome correlated strongly with the most severe degrees of oligohydramnios; 88% of the fetuses with severe oligohydramnios or anhydramnios had lethal outcomes, compared with 11% in the mild/moderate group. The presence of an anuric urinary tract anomaly was associated with the most severe grades of oligohydramnios and was uniformly fatal. Pulmonary hypoplasia was diagnosed in 60% of the severe group versus 6% in the moderate group. We conclude that subjective grading of oligohydramnios by experienced observers is both reliable and predictive of outcome. The finding of severe oligohydramnios in the second trimester is highly predictive of poor fetal outcome and should stimulate a thorough search for etiology and consideration of intervention. Moderate grades of reduced amniotic fluid may be managed with relative optimism.

Amniotic Fluid↗
PubMed1988

Ultrasonographic assessment of early fetal growth in insulin-treated diabetic pregnancies.

Early fetal growth aberrations have been suggested in diabetic gestations. To characterize such aberrations sonographically, longitudinal crown-rump length measurements were made in a group of 20 control and 20 diabetic pregnancies. The study evaluated growth between 40 and 100 days of amenorrhea. The best-fit curve of growth as a function of gestational age was that of a nonlinear polynomial regression curve for both the control and the diabetic groups. The correlation coefficients were 0.997 and 0.887 for the control and diabetic groups, respectively; the standard error of the estimate was 0.054 and 0.19, respectively. A log10 linear transformation was performed successfully on each curve. Comparison of the slopes and the intercepts of the transformed control and diabetic curves revealed no significant differences. To evaluate the possibility of a transient fetal growth delay, interval growths and interval growth velocities were compared between groups. No significant differences were observed. The control and diabetic groups' mean (+/- SD) growth velocities were 0.043 +/- 0.023 and 0.040 +/- 0.022 mm/day/mm total, respectively (p = NS). The growth of two anomalous fetuses in the diabetic group was studied individually. Their growth characteristics could not be distinguished from the control fetuses' growth profiles. The present study fails to confirm the presence of early fetal growth delay in diabetic pregnancies. Moreover, the data suggest that the fetuses' early growth in the mother with poorly controlled diabetes is similar to that of control fetuses.

Congenital Abnormalities↗
PubMed1987

Predictive value of early pregnancy glycohemoglobin in the insulin-treated diabetic patient.

The influence of early pregnancy glycemic control as measured by hemoglobin A1c concentration and the incidence of congenital anomalies and spontaneous abortions were evaluated in women presenting for prenatal care with insulin-treated diabetes in a population whose glycemic control was poor. Thirty-one abnormal outcomes were seen in 83 pregnancies (37%). There were 22 spontaneous abortions and nine major congenital anomalies. No woman with an early pregnancy hemoglobin A1C value less than 9.5% had an infant with a congenital anomaly and a single woman experienced a spontaneous abortion (4%). Conversely, in women with an early pregnancy hemoglobin A1C value greater than or equal to 9.5%, congenital anomalies occurred in 24% and spontaneous abortion in 35%. Outcomes of pregnancies in type 1 and type 11 diabetic women were comparable. A strong statistical relationship between hemoglobin A1C and adverse pregnancy outcomes was demonstrated. These results strongly suggest that poor glycemic control during early pregnancy adversely influences pregnancy outcomes; the greater the degree of poor control, the greater the impact on pregnancy outcome. The data further justify the need for preconceptional control in diabetic woman and for careful evaluation of the fetus during pregnancy in the woman with insulin-treated diabetes.

Adult↗