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Biomedical subjects

L D Platt

Publications and source records attributed to L D Platt.

At least 163 records · Page 9Linked to original sources

Ultrasonic estimation of weight in the very low-birth weight fetus: a resident versus staff physician comparison.

The estimation of weight in the very low-birth weight fetus (less than 1500 gm) is becoming more important in obstetric management as neonatal nurseries are reporting better outcome in this weight category. It has become clear that assessment of weight can best be accomplished through the use of ultrasound. In many institutions, however, ultrasonography is under the control of other departments and is not readily available. This arrangement prevents rapid access and compromises the benefit of the technique. To evaluate the accuracy of scans performed in very low-birth weight infants by personnel with limited training in ultrasonography, we undertook a systematic study of weight estimates in this select group of patients. To date, 31 ultrasound examinations have been performed by staff physicians and 50 by resident physicians. Comparisons made between ultrasound examinations by staff and resident physicians showed that the absolute error between the ultrasound-predicted weight and the actual weight, though less in the case of staff physician examinations, was not statistically significant.

Birth Weight↗

Isoimmunization in pregnancy to Gerbich antigen.

A case of hemolytic disease of the newborn due to Gerbich, a public antigen, is presented. The antibody which was IgG1 reacted in vitro with mononuclear phagocytes. Serial sonographic and amniotic fluid examinations were followed and a mildly jaundiced neonate was delivered. Further investigation may establish a relationship between severity of disease and IgG subclasses, a mononuclear phagocyte assay, and sonographic measurements. Sources of compatible blood for possible maternal, fetal, or neonatal transfusion include blood bank rare donor files, relatives, and autologous donation.

Adult↗

Effect of maternal intravenous glucose administration on fetal heart rate patterns and fetal breathing.

This study was undertaken to evaluate the effect of maternal intravenous (IV) administration of glucose on fetal breathing and its associated fetal heart patterns. Sixteen healthy women at term gestation participated in the study. The outcome of each of the pregnancies was normal. Fetal breathing and fetal electrocardiograms were simultaneously recorded by real time sonography and a fetal monitor respectively, and then digitized into a microcomputer. These women were studied for a 25-minute control period, given 50 gm of glucose IV and then, 20 minutes later, restudied for an additional 25-minute period. The results indicate that fetal breathing movements lasted for 24.8 +/- 6.2 percent of the time during the control period (mean +/- SEM) and were increased to 63.2 +/- 11.5 percent following the injection of glucose (P less than 0.01). Fetal heart rate decreased during fetal breathing by 2.3 and 2.1 beats per minute, before and after glucose administration, respectively (NS). Fetal breathing was associated with increased beat-to-beat variability by 1.32 +/- 0.5 and 1.27 +/- 0.3, before and after glucose administration, respectively (NS). This study confirms previous reports that the amount of time the fetus spends making breathing movements is significantly increased following maternal glucose administration, and demonstrates that the injection of glucose does not alter the modulation of fetal heart rate and beat-to-beat variability by fetal breathing.

Clinical Trials as Topic↗

Ovulation induction in clomiphene-resistant anovulatory women: differential follicular response to purified urinary follicle-stimulating hormone (FSH) versus purified urinary FSH and luteinizing hormone.

We studied 15 anovulatory women undergoing ovulation induction with purified human urinary FSH or purified human urinary FSH and LH [human menopausal gonadotropins (hMG)]. All patients had either sporadic or no vaginal bleeding after progesterone therapy and failed to ovulate after receiving clomiphene (250 mg for 5 days) plus hCG. Other causes of infertility were ruled out. Sixteen cycles of FSH and 12 cycles of hMG were administered according to a standard protocol. Estradiol, progesterone, androstenedione, testosterone, LH, and FSH concentrations were quantitated by RIA. Follicular diameter was determined using ultrasound. There was no significant difference in the amount of FSH or hMG used per patient, in the duration of therapy before hCG administration, or in the length of the luteal phase in any patient. There was a difference in the number of follicles greater than 1000 mm3 per cycle in those patients receiving FSH compared to the number in those receiving hMG [2.8 +/- 1.3 (+/- SEM) vs. 4.4 +/- 1.5 follicles; P = 0.026). The maximum follicular phase serum estradiol (18.3 vs. 34.8 ng/ml) and maximum luteal phase progesterone concentrations (1289 vs. 2808 pg/ml; P = 0.026) were also different between the FSH and hMG groups. Linear regression analysis revealed a significant correlation between the peripheral serum estradiol levels and the total follicular volume of follicles in the hMG-treated group which was not apparent in the FSH-treated group. These findings suggest that exogenous LH may not be required to induce folliculogenesis in anovulatory patients.

Adult↗

Evaluation of ultrasonic obstetrical parameters by hand-held calculator.

One consequence of the development of the use of ultrasound in obstetrics is the multiplication of parameters studied by the ultrasonographer. This has prompted the development of expensive computerized systems to assist the person doing the examination in evaluating his results. A program designed to be used with a relatively inexpensive, hand-held calculator is described. It gives the gestational age corresponding to the most commonly measured dimensions, the estimation of fetal weight of the examined fetus, and numerous other parameters used in clinical interpretation of ultrasound examinations.

Body Weight↗

The use of the abdominal circumference as a means of assessing M-mode ventricular dimensions during the second and third trimesters of pregnancy in the normal human fetus.

Eighty-two normal fetuses were scanned from 18 to 41 weeks of gestation. The following M-mode measurements were correlated with the abdominal circumference: diastolic biventricular outer (r = 0.951) and inner (r = 0.948) dimensions; diastolic right (r = 0.942) and left (r = 0.925) internal dimensions; tricuspid (r = 0.916) and mitral (r = 0.900) valve opening excursions; and right (r = 0.774), left (r = 0.731), and interventricular septal (r = 0.753) wall thickness. Polynomial regression demonstrated that linear regression best described the data from which the mean and 5 per cent and 95 per cent confidence limits for predicted M-mode measurements were computed for the abdominal circumference between 12 and 35 cm.

Embryonic and Fetal Development↗

The random measurement of the transverse diameter of the fetal heart: a potential source of error.

In a recent report it was suggested that the transverse diameter of the fetal heart measured randomly during the cardiac cycle from the real-time image was useful in predicting congenital heart disease (Jeanty P, Romero R, Cantraine F, et al: Fetal cardiac dimensions: a potential tool for the diagnosis of congenital heart disease. J Ultrasound Med 3:359, 1984). Comparing the above approach with M-mode measurements at end-diastole and end-systole suggests that random measurement of the transverse diameter is not appropriate for fetal cardiovascular evaluation because it could predict over 40 per cent of normal fetuses to have an "abnormally" increased cardiac dimension.

Echocardiography↗

False-positive amniotic fluid acetylcholinesterase results: the need for a multifacet approach to the prenatal diagnosis of neural tube defects.

Two cases are presented with false-positive amniotic fluid alpha-fetoprotein and acetylcholinesterase results for the prenatal diagnosis of neural tube defects. Stage II ultrasound revealed no lesions of the fetal spine in both cases. The alpha-fetoprotein and acetylcholinesterase results returned to normal on subsequent taps. Both pregnancies resulted in normal outcomes. A protocol is presented for managing pregnancies with abnormal alpha-fetoprotein and acetylcholinesterase results.

Acetylcholinesterase↗

Impact of fetal testing on maternal anxiety.

We evaluated the impact of fetal testing on maternal anxiety. A consecutive series of high-risk women attending during the third trimester for fetal assessment were each randomly assigned to one of four conditions: (1) high-feedback ultrasonography (n = 11), in which the monitor screen was visible; (2) low-feedback ultrasonography (n = 8), in which specific visual and verbal feedback was denied; (3) fetal heart rate monitoring (n = 11); or (4) a video control (n = 7), in which the women viewed a videotape of an ultrasonographic recording. Assessments were conducted before and after each procedure. No change was found in attitude ratings towards the fetus, although there was a significant reduction in state anxiety from before to after, with the reduction most pronounced in women undergoing high-feedback ultrasonography.

Adult↗

Nurse-midwifery in a large teaching hospital.

The role of the nurse-midwife in a busy obstetric hospital is explored. This report reviews the role and development of this service and teaching program in a high volume obstetric service. The relationship among the nurse-midwives, residents, and faculty demonstrates the ability of these services to work effectively with a high-risk population. The occasional complication in the obstetric patient as seen in this study dictates a close working relationship within the hospital environment. With the ever increasing demands being placed on obstetric care, a strong working relationship among health care professionals is essential.

Adolescent↗

Fetal echocardiography. IV. M-mode assessment of ventricular size and contractility during the second and third trimesters of pregnancy in the normal fetus.

M-mode echocardiographic examination of the right and left ventricles was performed on 82 normal fetuses between 18 and 41 weeks of gestation. The diameter of the right and left ventricles correlated with the biparietal diameter. The right/left ratio of the ventricular diameters remained constant (1:1) throughout gestation. Fractional shortening and mean circumferential shortening of both ventricles were independent of gestational age. The data presented in this paper will allow the clinician to evaluate abnormal fetal conditions that might affect cardiovascular structure and/or function.

Echocardiography↗

Increased beat-to-beat variability during uterine contractions: a common association in uncomplicated labor.

A computerized system was used during labor to provide a quantitative and objective analysis of fetal heart rate, beat-to-beat variability, and uterine contractions. Twenty-nine healthy pregnant women at term participated in this study. Each woman was studied for a 40-minute period during the active phase of spontaneous labor. The results indicate that beat-to-beat variability rises from a value of 4.62 +/- 1.11 (mean +/- SD) between contractions to 6.86 +/- 1.53 during contractions. This rise is significant (p less than 0.01). At the same time, changes in fetal heart rate are small, inconsistent, and not significant. We conclude that an increased beat-to-beat variability is commonly associated with uterine contractions in normal fetuses. This increase is probably due to mild hypoxia caused by decreased perfusion of the placenta and to increased vagal tone caused by fetal head compression.

Female↗

The role of nonstress tests, fetal biophysical profile, and contraction stress tests in the outpatient management of insulin-requiring diabetic pregnancies.

Antepartum fetal surveillance methods applicable in a home glucose-monitored population of pregnant diabetic women have been evaluated. A testing sequence of nonstress heart rate testing, backed up by either the fetal biophysical profile or contraction stress testing employed at a twice weekly interval, in 107 outpatients was compared with the management of 140 historic control patients by weekly nonstress tests and daily plasma estriols. There were 617 of 672 (91.8%) reactive nonstress tests in outpatients compared to 566 of 626 (90.4%) reactive tests in hospitalized control patients. Of 13 contraction stress tests performed in the outpatient group, only one was positive. Although 2,670 estriol determinations were done on hospitalized control patients, none was used for outpatients. No losses were attributed to unexplained antenatal stillbirth in either group. A fetal biophysical score of 8 was found to be at least as reliable as a reactive nonstress test. Antenatal surveillance in the well-controlled, insulin-requiring diabetic woman can be safely achieved with a testing sequence that consists of twice weekly nonstress tests backed up by the fetal biophysical profile and contraction stress tests.

Diabetes Mellitus, Type 1↗

The use of ultrasound in the diagnosis of fetal lung maturity.

We have shown that there is a relationship between a BPD of at least 9.2 cm and the presence of lung maturity in the fetus of a nondiabetic pregnancy. The presence of a grade III placenta in the late third trimester appears to be a reliable predictor of maturity, but more data need to be assessed before the utility of this method at any gestational age can be properly evaluated. We have discussed a scheme incorporating ultrasonographic observations and laboratory analysis in reducing the risk of iatrogenic hyaline membrane disease and reducing the need for amniocentesis.

Amniocentesis↗

Underestimation of fetal weight in premature rupture of membranes.

The accuracy of estimating fetal weight (EFW) by ultrasonographic techniques was analyzed after spontaneous premature rupture of the membranes (SPROM). The birth weights of 50 infants with SPROM delivered within 72 hours of ultrasound examination were compared with EFW based on ultrasonically measured parameters. The results indicate that EFW significantly underestimates birth weight in SPROM. The EFW based on biparietal diameter and abdominal circumference underestimated actual birth weight by an average of 12.4 per cent; EFW based on abdominal circumference alone, and on abdominal circumference and femur length, underestimated birth weight by 7.1 and 13.2 per cent, respectively.

Birth Weight↗

Continuing role of the nonstress test in the management of postdates pregnancy.

A retrospective analysis of 239 postdate patients who delivered within seven days of their last nonstress test between 1 July 1980 and 30 June 1981 was done to determine whether or not there was a relationship between variable fetal heart rate (FHR) decelerations, a decline in the FHR of at least 15 beats per minute and lasting 15 seconds, on the nonstress test and pregnancy outcome. Of the 505 nonstress tests, the results were considered either reactive (424 to 84%) or nonreactive (81 to 16%). Variable FHR decelerations or bradycardias were encountered on 95 nonstress tests (18.8%) in 80 (33.5%) postdate patients. Fetal heart rate bradycardia was encountered in nine patients (3.8%). Based on the last nonstress test, pregnancy outcome for the nonreactive group was less favorable than for the reactive group. However, when the reactive group was separated as to whether FHR decelerations or bradycardias were present or absent on the last test, the reactive group with FHR decelerations had a significant increase in meconium passage, cesarean delivery for fetal distress, and Apgar scores less than 7 at one minute. This group also had a similarly poor outcome as the nonreactive group of postdates patients. These data suggest that the nonstress test, when reactive without evidence of FHR decelerations, is a reliable indicator of fetal well-being in the postdate pregnancy. However, a reactive nonstress test with evidence of FHR decelerations is associated with a significant increase in perinatal morbidity.

Adolescent↗