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Biomedical subjects

B A Work

Publications and source records attributed to B A Work.

45 records · Page 3Linked to original sources
PubMedDate not supplied

Care in early pregnancy.

This century has seen marked improvement in perinatal outcomes but prematurity remains a problem the world over. To improve these results requires more attention to early pregnancy or even pre-pregnancy care. Control of pre-existing conditions, improved social behavior in nutrition, smoking cessation and other factors are discussed.

Female↗
PubMedDate not supplied

Prenatal prediction of small- and large-for-gestational age neonates.

OBJECTIVE: To test the predictive accuracy of five fundal height growth curves in the identification of twin gestations and small-, appropriate-, and large-for-gestational age neonates. DESIGN: Retrospective review of prenatal records. SETTING: Perinatal clinic at a tertiary-care center. PARTICIPANTS: Five hundred seven medically indigent women. MEASURES: Fundal height measurements were tested against the limits of normal for each week of gestation on five fundal height curves. Neonates were classified as small-, appropriate-, or large-for-gestational age (based on weight for gestational age), except for twin gestations, which were classified as twins. RESULTS: The accuracy of the predictions depended on which curve was used and what criteria were used to classify fundal height measurements as abnormal. Small-for-gestational age neonates (n = 40) were correctly predicted in 27.5-70% of the cases, large-for-gestational age neonates (n = 74) in 36.5-98.6% of the cases, and all four twin gestations. CONCLUSIONS: Clinicians should test the accuracy of any fundal height curve before using it in practice.

Anthropometry↗
PubMedDate not supplied

Predicting the duration of the first stage of spontaneous labor using a neural network.

To create a neural network that predicts the length of the first stage of term labor. Two hundred patients with gestations > or = 36 weeks, in spontaneous active labor are the study group: 159 for training and 41 for testing; 4 training set patients had second-stage cesarean section for obstructed labor. The network is designed with Brainmaker MacIntosh 1.0 (California Scientific Software). Inputs are uterine activity, estimated fetal weight, position, station, and gestational age; maternal parity, age, height, weight, membrane status, and cervical dilatation. Actual first stages are regressed on those predicted by the network or by a standard partogram set. Differences between actual first stage lengths and those predicted by the neural network or partogram are compared with t-tests; while the proportions of first stages accurately predicted within 1 or 2 h are compared for both methods with chi-square tests. The network trained in 4 h (1388 runs) to a 0.15 tolerance. The network predictions have significantly higher correlation (r = 0.88) than do standard partograms (r = 0.35) with actual first stage durations. Mean differences between predicted and actual first stages are significantly lower for network output than with partograms; these differences increased with first stages exceeding 3 h; 100% of trained network values are within 2 h of actual first stage length. The network performs similarly for a new set of 41 previously unseen labors. This neural network predicts the length of the first stage of spontaneous labor and uses inputs readily available to obstetricians. It outperforms typical partograms for estimating this important feature of normal labor. Future application for intrapartum prognosis could be based on this successful design.

Artificial Intelligence↗
PubMedDate not supplied

Relationship of psychological factors in pregnancy to progress in labor.

A prospective study of 32 normal, married primigravidas was conducted to determine the relationship between psychological factors in the third trimester of pregnancy and progress in two defined phases of labor. Data were analyzed for the total group and with five subjects deleted to control partially for the effect of medications. Psychological variables measured in pregnancy had significant correlations with variables measured at the onset of phase two labor. Conflict concerning the acceptance of pregnancy showed the most significant relationships to the phase two labor variables with correlations of .39 with anxiety, .59 with plasma epinephrine, -.70 and -.52 with two adjacent Montevideo units, and .58 with length of labor in phase two (3-10 cm cervical dilation). Other pregnancy variables which significantly correlated with the labor variables were identification of a motherhood role, history of psychological counseling or psychiatric treatment, the trait scale of the State-Trait Anxiety Inventory, and fears related to helplessness, pain, loss of control, and loss of self-esteem. Several psychological variables measured in pregnancy also correlated significantly with length of labor in phase three and type of delivery. The results demonstrate that specific psychological factors in pregnancy are predictive of progress in labor.

Adaptation, Psychological↗
PubMedDate not supplied

Breast massage to obtain contraction stress test.

A standard contraction stress test (CST) is usually obtained by the intravenous infusion of exogenous oxytocin for 1 to 3 hours. To assess whether breast massage could elicit a CST, 30 high-risk pregnant women between 37 and 44 weeks gestation massaged their breasts with mineral oil for a maximum of 40 to 60 minutes. Of the 21 patients (70%) who met the CST criterion, 15 had at least one spontaneous uterine contraction in the 20 minutes preceding breast massage, p = .05. Thirty-three percent of those who met the CST criterion did so within 10 minutes of the start of breast massage, and 95% met the criterion within 40 minutes. Other factors, including weeks gestation, parity, overstimulation, and fetal heart rate deceleration that could reasonably influence the effectiveness of the procedure are discussed. Breast massage appears to be an effective method for meeting the CST criterion.

Adolescent↗
PubMedDate not supplied

Measuring cervical dilatation in human parturition using the Hall effect.

An instrument was developed to continuously measure cervical dilatation in human labor. The instrument utilizes a small magnetic field source, which is attached to one edge of the cervix while a magnetic field sensor is attached to the diametrically opposite edge of the cervix. The sensor, using two Hall generators, measures orthogonal components of the field to minimize the effects of angular orientation between the source and sensor. The instrument's characteristics indicate that it can measure dilation throughout the range of 1-10 cm, but because its clinical reliability is consistent from only 1-7 cm, the equipment needs to be improved in the ways outlined in the text. This measurement, especially when analyzed with the continous measurement of intrauterine pressure, can provide the obstetrician with new insight into the physiology of labor.

Cervix Uteri↗