Biomedical subjects
Publications and source records attributed to Bruce K Young.
The literature on intrapartum fetal monitoring is reviewed emphasizing the pathophysiology, and current practice guidelines are discussed. FHR monitoring, ancillary tests, and investigational modalities are considered.
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OBJECTIVE: To review our experience with a minimally invasive technique for umbilical cord occlusion as a method of selective feticide in monochorionic sets. STUDY DESIGN: Umbilical cord occlusion was completed using 3 mm bipolar cautery under ultrasound guidance (3D/4D, n = 6; 2D, n = 6) with pre and post ligation endoscopic evaluation. RESULTS: 12 cases of monochorionic sets where selective feticide was performed were identified during the period 2000 to present. There were four triplet and eight twin gestations in the study cohort. Median interval from intervention to delivery was 16 weeks (range, 5-19). All co-twins survived the procedure and 15 of 16 were delivered after 33 weeks. CONCLUSIONS: Umbilical cord occlusion in monochorionic sets can be accomplished in a minimally invasive manner with combined endoscopic and ultrasound guidance in both twin and triplet pregnancies.
In the past decade, three-dimensional (3D) sonographic technology has matured from a static imaging modality to near-real-time imaging. One of the more notable improvements in this technology has been the speed with which the imaged volume is acquired and displayed. This has enabled the birth of the near-real-time or four-dimensional (4D) sonographic concept. Using the 4D feature of the current 3D sonography machines allows us to follow moving structures, such as fetal motion, in almost real time. Shortly after the emergence of 3D and 4D technology as a clinical imaging tool, its use in guiding needles into structures was explored by other investigators. We present a case in which we used the 4D feature of our sonographic equipment to follow the course and motion of an instrument inserted into the uterus to occlude the umbilical cord of a fetus in a case of twin-twin transfusion syndrome.
OBJECTIVE: By determining the early patterns of steroidogenesis in the most common aneuploidies, we have shown that there are differences between aneuploid and euploid pregnancy steroidogenesis patterns. We hypothesize that there are differences in steroidogenesis between specific trisomies, as well. METHODS: The records of all patients with a cytogenetic diagnosis of aneuploidy were studied. Serial data on progesterone(P), estradiol(E2) and beta-HCG(bHCG) was collected in the first trimester of aneuploid pregnancies. A matched group of normals at the same gestational ages was used as a control group. The specific trisomies of the above group were catalogued. RESULTS: 31 aneuploid pregnancies were reviewed for progesterone, estradiol and beta-HCG in the first trimester. Data was available for three or more patients with trisomy 16, 18, 21 and 22. Serial measurements between 5 and 10 weeks of pregnancy were obtained for P, E2, and bHCG. Gestational age was determined by LMP and serial sonograms. The progesterone, estradiol and beta-HCG levels were evaluated by calculating the rates of change between 5 and 10 weeks, rather than threshold values. The natural log of the values was used to plot serial data and reduce scatter due to the large natural variation in values between patients. The rates of change of P, E2 and b-HCG in the trisomic pregnancy groups were compared to matched normal pregnancies. The slopes of the curves for the trisomies and euploid pregnancies were calculated and compared. We determined that the rate of change of HCG for each of the trisomies was no different from euploid pregnancies, which is consistent with earlier data. In examining estradiol, trisomy 22 did not have a statistically different pattern of steroidogenesis, where trisomies 16, 18 and 21 were different than euploid (p < 0.05). With progesterone, trisomies 16, 18 and 22 had statistically different rates of change (p < 0.05), however trisomy 21 did not. CONCLUSIONS: As we have shown, in pregnancies with aneuploidy, there is a different pattern of steroidogenesis from euploid pregnancies. The difference is detectable in the first trimester by serial measurements of P and E2. In determining steroidogenesis in trisomies 16, 18, 21, and 22, we demonstrate that there is a difference in progesterone and estradiol levels over 5 to 10 weeks among the trisomies that can assist in the diagnosing of abnormal pregnancies in the first trimester. Furthermore, by looking at the rates of change of the individual steroids, the specific aneuploidy may be suspected. A large prospective study may reveal the clinical utility of these observations for early prenatal diagnosis of aneuploidy or probable spontaneous abortion.
OBJECTIVE: The hypothesis is that a risk score derived from the risk index (RI) is correlated with perinatal outcomes. STUDY DESIGN: The RI is a weighted numerical score based on gestational risk factors applied to 782 gravidas antepartum. Management was independent of the score. Birth weight, Apgar scores, and cesarean birth were correlated with risk score. RESULTS: The break point score in this non-Gaussian cohort was 6. Using 6, 80.2% were low and 19.8% high risk. Birth weight < 2500 gm was inversely correlated (p < .001) and occurred in 13% of the high risk ((3)6) and 4.9% of the low risk (< 6) group, relative risk (RR) 2.7. C-section correlated (p < .001), and occurred in 51% of the high and 23% of the low risk group, RR 2.4. risk score inversely correlated with 5 minute Apgar (RR 4.7 p < .002) but not the 1 minute Apgar score. CONCLUSION: The RI identified gravidas at risk for low birth weight, low 5 minute Apgar score, and cesarean birth.
OBJECTIVE: To describe a new technique for wound closure after endoscopic intrauterine procedures which prevents amniotic fluid leakage after the procedure. STUDY DESIGN: This is an observational study which reviews a new technique under an IRB-approved protocol. The rationale for this study was the increasing frequency of intrauterine endoscopic procedures. The most common complication of these procedures is persistent leakage of amniotic fluid from puncture sites, which can result in preterm labor and preterm delivery. Thus, these procedures carry a high morbidity rate that may overcome the benefit of the intervention. We have employed a new technique, which has successfully prevented amniotic fluid leakage following the procedure. The instruments used for the endoscopic procedures were no larger than 3.5 mm for all cases. A sealant of platelets was rapidly injected followed by injection of fibrin glue and powdered collagen slurry at each puncture site. Sonography for modified AFI, clinical examination for nitrazine and ferning, and pad count were performed after each procedure at three intervals: immediately after the procedure, 24 h and 48 h. RESULTS: Eight patients undergoing an endoscopic intrauterine procedure (either cord ligation for twin-twin transfusion syndrome or sealing of ruptured membranes after amniocentesis) were included. All patients were treated between 18 and 24 weeks of gestation. Sonography, clinical examination and pad count revealed no evidence of amniotic fluid leakage either intra-abdominally or vaginally in any of the patients. There was 1 patient who ruptured membranes 12 h after the procedure due to severe vomiting. Another patient elected to terminate the pregnancy 48 h after the procedure without evidence of leakage. The remaining patients continued for 8 weeks or more without fluid leakage. CONCLUSION: The technique described, immediate sealing of puncture wounds following endoscopic intrauterine procedures, is effective in preventing amniotic fluid loss after the procedure.
OBJECTIVE: To address the role that alloreactivity may play and better define the window for histoincompatible stem cell transplantation in utero. SUBJECTS, MATERIAL AND METHODS: We studied 9 fetal blood specimens obtained by cardiocentesis during elective abortions in the second trimester by multicolor flow cytometry and in vitro stimulation. RESULTS: Lymphocytes ranged from adult levels (3/9) to >90% leukocytes. Six specimens had T cells within adult range. T cells in the other specimens were reduced, while B cells were conversely elevated. This variability did not correlate with gestational age, or leukocyte composition. Following 4 h of mitogenesis, fetal CD4+ and CD8+ T cells from 1 of 5 specimens showed a response similar to that of maternal T cells, while the other 4 specimens showed a diminished response (0.3 +/- 0.2-fold). This heterogeneity did not correlate with gestational age, or lymphocyte subset distribution. Following 18 h of in vitro mitogenesis, fetal T cells from 2 specimens showed a response similar to that of maternal T cells (0.8 +/- 0.2-fold). Despite that, one specimen gave a 3-fold greater response in a one-way mixed lymphocyte reaction vs. maternal cells compared to the other specimen. CONCLUSION: We determine that fetal immunocompetence differs greatly during the second trimester and assessment of host vs. donor reactivity prior to in utero transplantation is likely to potentiate more favorable outcomes.