Biomedical subjects

F P Hadlock

Publications and source records attributed to F P Hadlock.

59 records · Page 4Linked to original sources

PubMed1979

Routine radiographic screening of the chest in pregnant women: is it indicated?

Experience with routine antepartum chest radiographic screening from July 1, 1976, through June 30, 1977, in a city-county hospital which serves a predominantly black indigent population was reviewed. The 5422 routine screening chest radiographs produced an extremely low yield of pathology (11 cases), and only 3 of the 11 cases were not suspected from the history or physical examination. Only 2 cases of active pulmonary tuberculosis were discovered, and both patients were recent immigrants from countries with a much higher incidence of tuberculosis. This low case finding probably reflects the general decline in incidence of pulmonary tuberculosis in the United States and suggests that routine screening chest radiographs (done primarily to exclude tuberculosis) are no longer indicated in our pregnant population.

Adult↗

PubMedDate not supplied

The use of ultrasound in the assessment of normal fetal growth: a review.

This review presents the basic principles underlying the quantitative assessment of normal fetal growth using ultrasound. Data on fetal growth derived from measurements of body, head, chest, and abdominal dimensions, are summarized, compared, and evaluated. Fetal volume and weight determination are also discussed. Most of the data evaluated were obtained in cross-sectional studies, but we present the preliminary results of our longitudinal study of fetal growth for comparison.

Abdomen↗

PubMedDate not supplied

Longitudinal studies of fetal growth using volume parameters determined with ultrasound.

To explore the use of three-dimensional parameters in characterizing fetal growth with ultrasound, the accuracy of volume measurements and the ability to make such measurements during pregnancy have been investigated. Total fetal volumes (TOTV) determined with ultrasound in utero were compared to volume measurements obtained by hydrostatic weighing following induced abortion at 19.4 (+/- 1.8 SD) weeks, menstrual age (MA), and to those calculated from birth weights and density values for term fetuses [39.3 (+/- 0.8 SD) weeks, MA]. This study indicated that ultrasound measurements underestimate the fetal volume [-9.8 (+/- 9.5 SD)% at 19 weeks and -19.0 (+/- 9.3 SD)% at 39 weeks]. To assess the possibility of obtaining growth curves for volume parameters, 20 normal fetuses [based on crown-rump length (CRL), biparietal diameter (BPD), head circumference (HC) and abdominal circumference (AC) growth curves, birth weight (WT), crown-heel length (CHL) and postnatal examination] with known dates of conception were studied. Head volume (HV), thoracic volume (TV), abdominal volume (AV), limb volume (LV) and TOTV were measured at 2- to 3-week intervals during the third trimester. Mathematical modeling indicated that the linear-cubic (LC) model was optimal for HV, TV, AV, and TOTV (R2: 97.3%, 97.2%, 98.1% and 99.4%) while the linear-quadratic (L-Q) model was optimal for LV (R2: 98.4%). Significant individual variation was suggested by the high coefficients of variation (CV) obtained for the optimal model coefficients. Inspection of individual growth curves revealed the presence of three types, "linear," "concave," and "convex" with the "concave" type predominating. The variability was less than that seen in the groups as a whole for most subgroups but was still greater than that observed with linear parameters. These results indicated that although volume growth curves can be obtained, their individual variability is significant and thus more fetuses must be studied before standard curves can be defined.

Abdomen↗

PubMedDate not supplied

Longitudinal studies of thigh circumference growth in normal fetuses.

To characterize the growth of the thigh circumference (ThC) in individual fetuses, longitudinal studies of ThC growth were carried out in 20 fetuses between 19 (+/- 1.8) and 38 (+/- 1.5) weeks, menstrual age. Because of measurement uncertainties, analysis of growth patterns was limited to the data collected after 22 weeks. The Rossavik growth model fit the data well [R2: 95.8(+/- 2.9 SD)%], but considerable coefficient variability was seen, particularly for the coefficient k. Use of the coefficient k-value (1.138) derived from a cross-sectional data set reduced the variability of the coefficient c by 95% and made the results of the longitudinal and cross-sectional studies consistent with each other. This k-value was taken as the appropriate one for ThC growth curves. Studies of ThC growth in individual fetuses revealed considerable variability in growth curve shape, although the majority of curves could be approximated by a straight line. No differences between growth curves for males and females could be detected. The average longitudinal ThC growth curve was found to be very similar to the growth curve obtained in a cross-sectional study of ThC growth. ThC growth after 26.1 weeks could be predicted with an accuracy of +/- 15% from growth models derived from the data obtained before 26.1 weeks. These results indicate that ThC growth after 22 weeks (as with other parameters) can be followed in individual fetuses. However, because of the greater inherent variability in growth patterns, using each fetus as its own control may be more important.

Embryonic and Fetal Development↗

PubMedDate not supplied

An evaluation of two methods for measuring fetal head and body circumferences.

Head and abdominal circumference measurements of 166 fetuses (15-40 weeks) were made by three different examiners using two measurement techniques. In method 1 the actual circumferences were measured using an electronic digitizer, while in method 2 the circumference measurements were estimated using the formula for calculating the circumference for an ellipse. Evaluation of the entire data set as a whole demonstrated no significant mean errors (P > 0.05), and only a small degree of variability (2 SD = 6 per cent). Evaluation of the data for each examiner demonstrated no significant differences (P > 0.05) in the observed variability, but small statistically significant mean errors (1.7-4.1 per cent) were observed. The latter finding is thought not to be a limitation of the ellipse approximation technique, since similar findings have been observed when experienced sonographers make actual circumference measurements on the same fetus using the same equipment.

Embryonic and Fetal Development↗