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Biomedical subjects

R J Wapner

Publications and source records attributed to R J Wapner.

At least 91 records · Page 5Linked to original sources

Risks of chorion villus sampling.

From the experience accumulated in less than 4 years of chorionic villus sampling activity, much has been learned about the advantages of prenatal diagnosis in the first trimester. The safety of the procedure during this developmental stage has been extremely good. The record in this centre with over 2700 cases sampled and over 2000 deliveries has demonstrated a fetal loss rate similar to that observed in amniocentesis studies. It appears that fetal loss that may be attributed to the procedure is not more than 1% and may be less. Some of that loss appears to be correlated with avoidable trauma to the chorionic membrane area. If this conclusion is valid, then avoidance of this pattern even in the occasional difficult case may further improve the already acceptable safety record of the procedure.

Biopsy, Needle↗

Significance of membrane thickness in the sonographic evaluation of twin gestations.

A retrospective study of 55 twin pregnancies was performed to determine the role of sonography in distinguishing between dichorionic and monochorionic diamniotic gestations solely by evaluating the thickness of the membrane between the fetuses. The presence of a thick dividing membrane indicated a dichorionic diamniotic gestation in 38 (90%) of 42 cases in which it was identified. Inability to identify a membrane between dichorionic diamniotic twins occurred most commonly during the third trimester. A thin membrane indicated monochorionic diamniotic twinning and was seen in three (25%) of 12 cases. Membrane thickness was indeterminate in one case. Therefore, on the basis of the thickness of the dividing membrane imaged by sonography, dichorionic diamniotic gestations can be distinguished from monochorionic diamniotic gestations. Inability to show a separating membrane by sonography, however, can occur with any form of twin gestation, particularly in the third trimester. Membrane thickness should be used in conjunction with other sonographic criteria to predict the amnionicity and chorionicity of twin gestations.

Extraembryonic Membranes↗

Use of the Greenfield filter for thromboembolic disease in pregnancy.

Recent technical advances in surgical intervention for thromboembolic disease have made the Greenfield filter a safe and effective treatment when heparin is contraindicated or recurrent emboli develop. One successful use of Greenfield filter placement in pregnancy has been reported. We report six additional cases. Maternal morbidity was negligible, and fetal outcomes were good. The use of the Greenfield filter as an adjunctive therapy for treatment of severe thromboembolic disease in pregnancy appears to be safe and should be considered in appropriate candidates.

Adult↗

In utero analysis of heterozygous achondroplasia: variable time of onset as detected by femur length measurements.

Seven cases of heterozygous achondroplasia were examined in utero. Although the head shape and growth were normal, the initially normal femur length showed a decrease in growth and fell below the lower 99 per cent confidence limit in all cases. The time of presentation of achondroplasia varied between 21 and 27 gestational weeks. This study suggests that the diagnosis of achondroplasia can be reasonably made when the femur is abnormally short. When the femoral length is appropriate prior to 30 weeks, more caution should be taken in interpretation. Because of the variability in presentation, the fetus could be normal or still could be affected.

Achondroplasia↗

Subclinical autoimmune disease and unexplained abortion.

Although it seems likely that some patients with unexplained repeated abortions have early or subclinical autoimmune disease, there are no reports on the incidence of autoimmune serologic abnormalities in such patients by use of a series of tests. This diagnosis would suggest a treatable etiology for reproductive loss. We performed 11 serologic autoimmune tests in sera from 14 patients with three or more unexplained abortions (group II) and compared these results to those of 16 control patients with an established diagnosis for repeated abortions (group I). The groups were similar in age, gravidity, number of spontaneous abortions and live births, and in the interval from last abortion to serum sampling. A positive antinuclear antibody test plus at least one other positive test was found in four of 14 (29%) patients in group II (p less than 0.05). The tests that identified all these patients included levels of antinuclear antibody, antibodies to DNA or extractable nuclear antigen, and low levels of complement 3.

Abortion, Habitual↗

Factors related to subsequent reproductive outcome in couples with repeated pregnancy loss.

Specific factors in a couple's history may influence the recurrence risk following repeated pregnancy loss (RPL). Couples with RPL were contacted several years following evaluation and information concerning subsequent pregnancies was obtained. Linear regression analysis was utilized to determine which factors in the history were significant predictors of pregnancy outcome following evaluation. A family history of RPL or a "genetic defect" was a highly significant predictor of subsequent unsuccessful pregnancies. Surgical, but not medical, treatment for RPL was a significant predictor of eventual successful outcome. The number of abortions prior to evaluation for RPL, presence of a liveborn child, maternal age at evaluation, and intercurrent infertility all failed to be significant predictors of pregnancy outcome after evaluation.

Abortion, Habitual↗

The inaccuracy of total uterine volume measurements: sources of error and a proposed solution.

Inaccuracies in total intrauterine volumes calculated using the prolate ellipse equation have been reported. No previous study has examined all the sources of error. In this study, a comprehensive approach was undertaken. Measurements were obtained from scans of the pregnant uterus in the prone position using an automated water-path scanner (Octoson) and in the supine position using standard static B-mode scanners. Several conclusions could be drawn: 1) From the Octoson prone scans, uterine volumes obtained using the prolate ellipse formula were markedly different from the true uterine volumes obtained by the summation of stepped areas. This showed that the prolate ellipse formula was inaccurate. 2) From the static supine scans, many observer inconsistencies were found in uterine volumes obtained from the prolate ellipse formula. This made the prolate ellipse formula unreliable. 3) Previously published graphs calculated from the prolate ellipse equation, comparing fetal age with total intrauterine volume, were found to vary accuracy, presumably as a result of 1 and 2. A more accurate approach is proposed. Using the outer uterine wall as the boundary, the stepped area-to-volume values of transverse scans taken at 3-cm intervals were found to closely approximate true volumes, with an average error of only 3.5 per cent. Since these measurements encompass the intrauterine contents and the myometrium, it is suggested that the term "total uterine volume" be used instead of "total intrauterine volume."

Amniotic Fluid↗

Total uterine volume: a new graph and its clinical applications.

The prolate ellipse formula has been shown to be inaccurate and inconsistent in the calculation of total uterine volume. The stepped area-to-volume technique has proven to be both accurate and consistent and provides a value equal to the true uterine volume. When these true volumes were plotted on previously published graphs of total uterine volume derived from the prolate ellipse formula, the graphs were found to be inaccurate. New graphs based on normal values have been constructed, comparing total uterine volume with both biparietal diameter and average gestational age. When 26 abnormal values were plotted on the total uterine volume versus biparietal diameter graph, almost all fell outside the 90 per cent confidence limits. Seven of the abnormal value were from fetuses found to have growth retardation. Six of these cases, including two not appreciated either clinically or ultrasonographically, were detected by this method. The stepped area-to-volume technique should allow reconsideration of the total uterine volume concept and aid in the detection of the subtle changes in uterine size.

Amniotic Fluid↗

Repeated pregnancy loss.

Debate persists over the value of chromosome analysis of couples with repeated pregnancy loss. Therefore, we studied the records of all patients referred to the Genetics Division at Thomas Jefferson University for repeated pregnancy loss. Couples were divided into three groups according to the reason for evaluation. In group I (two consecutive abortions) significant chromosome abnormalities were found in 1.8% of individuals; in group II (three or more consecutive abortions) 2.3% of individuals had a chromosome abnormality; and in group III (50% fetal loss) 1.8% of persons had abnormal chromosomes. These rates are lower than those reported by others, but are still ten times higher than those expected in the general population and affirm the value of doing a chromosome study in such couples. In addition, we found increased incidence of liveborn offspring with congenital abnormalities in couples evaluated for the above indications, and found a high incidence of a family history of repeated suboptimal pregnancy outcome. The significance of these findings is discussed.

Abortion, Habitual↗

Ultrasonographic diagnosis of second-trimester skeletal dysplasias: a prospective analysis in a high-risk population.

Sixteen pregnancies in 15 women at high genetic risk for having fetuses with skeletal dysplasias were examined by use of ultrasonography during the second trimester. In addition to the routine examination of fetal head and body, the fetal calvarium, spine, ribs, pelvis, and long bones were specifically evaluated for bone brightness, deformity, fractures, and inappropriate growth. It was determined that 11 of the 16 fetuses were normal and five were abnormal. At birth, all 11 ultrasonographically determined normal fetuses were normal, and at birth or elective termination of pregnancy the other five were abnormal. All abnormalities detected by ultrasonography in the affected fetuses were found at delivery, including decreased bone brightness, deformity of the head and long bones, and fractures and abnormal growth of the long bones. On the basis of this study, it is felt that ultrasonography is highly accurate for the diagnosis of many second-trimester skeletal dysplasias.

Bone Diseases, Developmental↗

Ultrasonographic findings in placenta increta.

Placenta increta, invasion of the myometrium by normal placental (chorionic) villi, can be life-threatening to a mother at delivery. In two reported cases of pathologically proven placenta increta, the abnormal areas were retrospectively identified on ultrasonographic images. In both cases, there was consistent focal obliteration of the hypoechoic retroplacental zone by either tissue of echogenicity similar to that of the normal placenta or tissue of slightly decreased echogenicity. This was found to represent extension of the villi through the decidua basalis into the myometrium. The spectrum of non-malignant invasive placentas and the specific ultrasonographic findings that should allow prospective diagnosis are discussed.

Decidua↗