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Biomedical subjects

J C Hobbins

Publications and source records attributed to J C Hobbins.

At least 19 recordsLinked to original sources
PubMed1992

Atelosteogenesis type II: sonographic and radiological correlation.

Atelosteogenesis type II is a lethal chondrodysplasia characterized by severe micromelia, spinal abnormalities, talipes equinovarus, and abducted thumbs and toes. We present a case diagnosed at 21 weeks of gestation in which antenatal sonographic and post-mortem radiological findings were correlated. The patient had a recurrence of this disorder in a subsequent pregnancy which was terminated at 15 weeks, supporting previous reports of an autosomal recessive inheritance pattern. The feasibility of diagnosing the following morphological features by prenatal ultrasonography is demonstrated: coronal clefts of the vertebral bodies, metaphyseal and epiphyseal abnormalities, spinal deviations such as cervical kyphosis and a horizontal sacrum, additional ossification centres in the pelvis, and preaxial deviation of the thumbs and toes. The differential diagnosis of this disorder from other skeletal dysplasias with similar features is discussed.

Abnormalities, Multiple↗
PubMed1992

Embryoscopy: a closer look at first-trimester diagnosis and treatment.

Advancing technology has made the fetus and its environment even more accessible to prenatal diagnosis and treatment. The current approach to prenatal diagnosis relies mainly on the use of high-resolution ultrasonography. However, as attempts are made to conduct antenatal diagnoses earlier in gestation, the limits of ultrasonography are approached. Embryoscopy allows for direct visualization of the first-trimester fetus with a fiberoptic endoscope. A customized side channel enables the operator to pass a variety of diagnostic tools and gain access into the fetal circulation. The further development and refinement of this technology are expected to change early prenatal diagnosis and treatment considerably. The potential contribution of this technique to perinatal medicine is readily apparent when it is placed in historic context. Undoubtedly, many ethical, legal, and regulatory questions will have to be addressed before the full potential of embryoscopy is realized. The responsibility for the judicious use of this powerful technology for prenatal intervention will have to be shared by the scientific community and a well-informed public.

Endoscopes↗
PubMed1992

Fetal humeral length to detect Down syndrome.

OBJECTIVE: Our aim was to evaluate the utility of ultrasonographic humeral length measurements for detection of fetuses with Down syndrome in the midtrimester of gestation. STUDY DESIGN: Ultrasonographic biometry data obtained before genetic amniocenteses on 43 fetuses with Down syndrome and 204 randomly chosen normal fetuses were analyzed. Regression equations relating biparietal diameter to humeral length and femoral length were used to calculate ratios of observed-to-expected length and sensitivity and specificity at various cutoff points. RESULTS: Humeral length in Down syndrome fetuses was significantly shorter than in normal controls (p less than 0.001). A ratio of 0.90 for observed/expected humeral length yielded a sensitivity of 28%, a specificity of 91%, and positive predictive values of 1.23% and 0.41% in populations at risk for Down syndrome of 1 in 250 and 1 in 750, respectively. The equivalent ratio for femoral length yielded a sensitivity of 19%, a specificity of 91%, and positive predictive values of 0.87% and 0.28% for baseline risks of 1 in 250 and 1 in 750, respectively. CONCLUSIONS: The sensitivity of fetal humeral length measurements for Down syndrome detection in our hands was remarkably lower than previously reported. Independence of this parameter from currently used serum screening markers has not been established; therefore implementation in screening programs is not advisable at this point.

Down Syndrome↗
PubMed1992

A controlled trial of self-nonstress test versus assisted nonstress test in the evaluation of fetal well-being.

OBJECTIVE: New portable devices have become available for home monitoring of fetal heart rates; these devices have the potential to immediately transmit these tracings to a medical facility. The null hypothesis of this study is the inability of mothers to perform their own nonstress tests (self-nonstress tests) and that such tests are not comparable to those performed by professional medical personnel (assisted nonstress tests). STUDY DESIGN: The feasibility of maternal self-testing was established in 50 high-risk patients followed by a controlled clinical trial conducted in 60 patients. The latter study represents the first controlled trial in which patients performed self-nonstress tests at their homes and transmitted the tracings via telecommunication to our perinatal unit. In all cases these patients came to our hospital within 60 minutes after the self-nonstress tests to have a perinatal nurse perform a second nonstress test. The pairs of self and assisted fetal heart rate tracings were independently reviewed by two investigators. RESULTS: The self and assisted tracing pairs were judged satisfactory for interpretation in 100% and 90%, respectively; self and assisted were interpreted by each examiner to be nonreactive in 20% and 14%, respectively. However, both examiners were unable to distinguish between tracings generated by assisted nonstress and self-nonstress tests. Furthermore, cost analysis revealed an estimated twofold savings with self-nonstress testing compared with the assisted nonstress test. CONCLUSION: Self-nonstress testing is a reliable and accurate method of antepartum fetal heart rate testing. This method of fetal assessment not only introduces a new approach to fetal surveillance with added convenience to patients, but may also significantly reduce medical cost without compromising the results of fetal testing.

Costs and Cost Analysis↗
PubMed1992

Bilateral choroid plexus cysts in trisomy 21.

Whether karyotyping is indicated in a fetus with choroid plexus cysts who is otherwise structurally normal is still controversial. Many authors have suggested basing the decision on cyst size, bilaterality, persistence with advancing gestational age, and association with other anomalies. We report a case of large bilateral choroid plexus cysts in a fetus with trisomy 21 who had no evidence of congenital anomalies or ultrasonographic signs of Down syndrome. Cyst sizes diminished by half over a 3-week period of follow-up. It appears that diminishing size alone should not be considered sufficient reassurance about the normality of the fetal karyotype. A similar case has been previously reported, and it is conceivable that choroid plexus cysts are associated not only with trisomy 18 but also with trisomy 21.

Adult↗
PubMed1992

Monitoring of intravascular fetal transfusions with Doppler velocimetry.

Intravascular fetal transfusions are occasionally complicated by extravascular deposition of transfused blood or by fetal bradycardia on penetration of the needle into the umbilical cord. It is desirable therefore to continuously monitor the intravascular location of the needle and the fetal heart rate. This can be achieved by Doppler velocimetry of the umbilical vein and artery during the procedure. The technique is easily performed, does not require moving of the ultrasonography transducer, and appears to be time efficient.

Blood Transfusion, Intrauterine↗
PubMed1992

Fetuses with Down syndrome have disproportionately shortened frontal lobe dimensions on ultrasonographic examination.

OBJECTIVE: The purpose of our study was to determine whether the frontal lobe is significantly smaller than normal in the Down syndrome fetus in midtrimester. STUDY DESIGN: Frontothalamic distance, measured from the inner table of the frontal bone to the posterior thalamus, and frontothalamic distance/biparietal diameter ratio were compared in 125 normal and 19 Down syndrome fetuses between 16 and 21 weeks' gestation. RESULTS: In the Down syndrome group 52% had frontothalamic distance < 10th percentile. When the frontothalamic distance and the frontothalamic distance/biparietal diameter ratio were expressed as multiples of the normal median to eliminate variation caused by gestational age, the mean value of multiples of the median in Down syndrome fetuses was compared with the mean value of multiples of the median in normal fetuses and was found to be significantly smaller (p < 0.0019 and p < 0.0177, respectively). When an observed-to-expected frontothalamic distance ratio of < or = 0.84 is used as a cutoff to screen for Down syndrome, sensitivity, specificity, and positive predictive values of 21.2%, 95.2%, and 1.2%, respectively, are achieved in a population with a 1:270 risk. CONCLUSION: Frontal lobe dimension is significantly shortened in Down syndrome fetuses.

Down Syndrome↗
PubMed1992

Fetal blood sampling in human immunodeficiency virus--seropositive women before elective midtrimester termination of pregnancy.

OBJECTIVES: To explore the diagnostic potential of fetal blood sampling in the prenatal diagnosis of intrauterine human immunodeficiency virus infection and to investigate the transplacental transfer of human immunodeficiency virus antibody and p24 antigen in the second trimester of pregnancy, we studied serum and amniotic fluid obtained from 13 seropositive women and their fetuses before elective termination of pregnancy. STUDY DESIGN: Enzyme-linked immunosorbent assay, Western blot antibody analyses, and p24 antigen assays were performed on all samples. RESULTS: Human immunodeficiency virus antibody was detected by enzyme-linked immunosorbent assay and Western blot analysis in aliquots of maternal serum, amniotic fluid, and fetal serum from all 13 pregnancies. Each mother-fetus pair had identical antibody banding patterns. In contrast, p24 antigen was found in the maternal serum and amniotic fluid samples from five of 13 women (38%) and in serum from only three of 13 fetuses (23%). CONCLUSIONS: We conclude that fetal blood sampling, if combined with sophisticated serologic analysis, may have the potential to provide the diagnosis of congenital infection with human immunodeficiency virus. The correlation of immunologic, virologic, and molecular biologic methods with subsequent infant outcome and risk of iatrogenic infection of the fetus remains to be determined.

Abortion, Induced↗
PubMed1992

Prevalence and prognostic significance of anticardiolipin antibodies in pregnancies complicated by human immunodeficiency virus-1 infection.

OBJECTIVES: Anticardiolipin antibodies are estimated to occur in 2.2% of all pregnancies and are associated with adverse outcomes including thrombotic events, fetal wastage, intrauterine growth retardation, and preterm delivery. We studied 32 human immunodeficiency virus-seropositive gravidas (1) to determine the prevalence of anticardiolipin antibodies in pregnant women infected with human immunodeficiency virus-1 and (2) to investigate the association between the presence of anticardiolipin antibodies and pregnancy outcome, disease status, and perinatal transmission of human immunodeficiency virus-1. STUDY DESIGN: Serum samples obtained at the first prenatal visit were analyzed for anticardiolipin immunoglobulin M and immunoglobulin G by enzyme-linked immunosorbent assay. Relevant antepartum, intrapartum, and postpartum data, including maternal CD4+ lymphocyte subsets, human immunodeficiency virus p24 antigen determinations, Venereal Disease Research Laboratory test, hematocrit, platelet counts, and placental pathologic tissue of the anticardiolipin antibody-positive and anticardiolipin antibody-negative groups were compared. RESULTS: Test results for 17 (53%) of patients were positive for anticardiolipin antibody: 4 had only immunoglobulin M, 1 had only immunoglobulin G, and the remaining 12 had both antibodies. The patients in the anticardiolipin antibody-positive group were delivered of infants with a mean gestational age of 39 weeks and mean birth weight of 2983 gm. In the anticardiolipin antibody-negative group 15 deliveries had a mean gestational age of 36.3 weeks and a mean birth weight of 2330 gm. CONCLUSIONS: We conclude that there is a high prevalence of anticardiolipin antibodies in patients who have human immunodeficiency virus, which is not associated with adverse maternal or neonatal outcome, maternal human immunodeficiency virus status, or perinatal transmission of human immunodeficiency virus-1.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Limb-body wall complex associated with cocaine abuse: further evidence of cocaine's teratogenicity.

Limb-body wall complex is a complicated fetal malformation with the essential features of body wall disruption and limb abnormalities. Data from studies in the rat model suggest that vascular disruption is an etiology for limb-body wall complex. Because of its vasospastic properties, cocaine can act as a teratogen by impairing uteroplacental fetal blood flow during critical periods of development. We describe the prenatal detection of two fetuses with limb-body wall complex, whose mothers smoked large amounts of cocaine during the first trimester of pregnancy. Ultrasonographic evaluation of the fetus should be offered routinely in pregnancies complicated by maternal cocaine abuse.

Abdominal Muscles↗
PubMed1992

New technique for genetic amniocentesis in twins.

A new technique is described for amniocentesis in twins. Using a curvilinear or linear transducer, the separating membrane and an adjacent pocket of amniotic fluid in each cavity are simultaneously visualized. An amniocentesis needle is advanced into the first cavity. A second needle is introduced into the other amniotic cavity without altering the position of the transducer. This technique permits visualization of both needles simultaneously, providing proof of proper placement of the needle in each cavity. The advantages are unambiguous evidence of correct sampling of each cavity and lack of necessity for injection of a foreign substance into the amniotic sac. Finally, hard-copy documentation of proper needle placement is generated for the records. This procedure has been performed in seven twin sets with good results and patient acceptance.

Amniocentesis↗
PubMed1991

Prenatal diagnosis of a fetus with terminal deletion of chromosome 1 (q41)

Many authors have suggested that individuals affected by a terminal 1q deletion display a phenotypically definable and recognizable syndrome. In all of the 27 cases reported to date, the breakpoints were at band q42 or distally to it. To our knowledge, we report the first case of a terminal 1q41 deletion. Diagnosis was made prenatally by amniocentesis, following ultrasonographic diagnosis of omphalocele, cerebral ventriculomegaly, and increased nuchal fold thickness in a 19-week female fetus. Multiple facial and extremity features were consistent with the proposed distal 1q deletion syndrome; omphalocele, however, has not been reported previously. The absence of liver herniation into the omphalocele sac in this case supports the previously reported association of this finding with chromosomal anomalies.

Abnormalities, Multiple↗