Obstetrician & Gynecologist (OB/GYN)
24 years of experience

Accepting new patients
Northwest Dallas
5323 Harry Hines Blvd
Dallas, TX 75390
214-590-5218
Locations and availability (4)

Education ?

Medical School Score Rankings
University of Kansas (1986)
  • Currently 3 of 4 apples
Top 50%

Awards & Distinctions ?

Associations
American Board of Obstetrics and Gynecology

Affiliations ?

Dr. Roberts is affiliated with 5 hospitals.

Hospital Affilations

Score

Rankings

  • UT Southwestern University Hospital - Zale Lipshy
    5151 Harry Hines Blvd, Dallas, TX 75235
    • Currently 4 of 4 crosses
    Top 25%
  • UT Southwestern University Hospital - St. Paul
    5909 Harry Hines Blvd, Dallas, TX 75235
    • Currently 4 of 4 crosses
    Top 25%
  • Dallas County Hospital District
  • Wesley Medical Center
  • Parkland Health & Hospital System
  • Publications & Research

    Dr. Roberts has contributed to 34 publications.
    Title Presentation of Seasonal Influenza A in Pregnancy: 2003-2004 Influenza Season.
    Date May 2010
    Journal Obstetrics and Gynecology
    Excerpt

    To describe the clinical course of influenza in pregnant women followed at our institution during the 2003-2004 influenza season.

    Title Maternal and Neonatal Outcomes After Antepartum Treatment of Influenza with Antiviral Medications.
    Date May 2010
    Journal Obstetrics and Gynecology
    Excerpt

    To review the maternal and neonatal outcomes after antepartum exposure to M2 ion channel inhibitors or oseltamivir to provide some guidance on the risk, if any, of antiviral medication during pregnancy.

    Title Assessing the Potential Impacts to Riparian Ecosystems Resulting from Hemlock Mortality in Great Smoky Mountains National Park.
    Date September 2009
    Journal Environmental Management
    Excerpt

    Hemlock Woolly Adelgid (Adelges tsugae) is spreading across forests in eastern North America, causing mortality of eastern hemlock (Tsuga canadensis [L.] Carr.) and Carolina hemlock (Tsuga caroliniana Engelm.). The loss of hemlock from riparian forests in Great Smoky Mountains National Park (GSMNP) may result in significant physical, chemical, and biological alterations to stream environments. To assess the influence of riparian hemlock stands on stream conditions and estimate possible impacts from hemlock loss in GSMNP, we paired hardwood- and hemlock-dominated streams to examine differences in water temperature, nitrate concentrations, pH, discharge, and available photosynthetic light. We used a Geographic Information System (GIS) to identify stream pairs that were similar in topography, geology, land use, and disturbance history in order to isolate forest type as a variable. Differences between hemlock- and hardwood-dominated streams could not be explained by dominant forest type alone as forest type yields no consistent signal on measured conditions of headwater streams in GSMNP. The variability in the results indicate that other landscape variables, such as the influence of understory Rhododendron species, may exert more control on stream conditions than canopy composition. The results of this study suggest that the replacement of hemlock overstory with hardwood species will have minimal impact on long-term stream conditions, however disturbance during the transition is likely to have significant impacts. Management of riparian forests undergoing hemlock decline should, therefore, focus on facilitating a faster transition to hardwood-dominated stands to minimize long-term effects on water quality.

    Title Ampicillin Resistance and Outcome Differences in Acute Antepartum Pyelonephritis.
    Date November 2008
    Journal Infectious Diseases in Obstetrics and Gynecology
    Excerpt

    OBJECTIVE: To measure the incidence of ampicillin-resistant uropathogens in acute antepartum pyelonephritis and to determine if patients with resistant organisms had different clinical outcomes. STUDY DESIGN: This was a secondary analysis of a prospective cohort study of pregnant women admitted with pyelonephritis, diagnosed by standard clinical and laboratory criteria. All patients received ampicillin and gentamicin. RESULTS: We identified 440 cases of acute pyelonephritis. Seventy-two percent (316 cases) had urine cultures with identification of organism and antibiotic sensitivities. Fifty-one percent of uropathogens were ampicillin resistant. The patients with ampicillin-resistant organisms were more likely to be older and multiparous. There were no significant differences in hospital course (length of stay, days of antibiotics, ECU admission, or readmission). Patients with ampicillin-resistant organisms did not have higher complication rates (anemia, renal dysfunction, respiratory insufficiency, or preterm birth). CONCLUSION: A majority of uropathogens were ampicillin resistant, but no differences in outcomes were observed in these patients.

    Title The Metabolism and Transplacental Transfer of Oseltamivir in the Ex Vivo Human Model.
    Date July 2008
    Journal Infectious Diseases in Obstetrics and Gynecology
    Excerpt

    Oseltamivir phosphate is extensively metabolized in the ex vivo human placenta model, and the transplacental passage of the metabolite oseltamivir carboxylate is incomplete. OBJECTIVE: To evaluate the metabolism and transplacental transfer of oseltamivir (Tamiflu) in the ex vivo human placental model. STUDY DESIGN: Perfusion studies were performed in six placentas from term, uncomplicated deliveries. Concentrations of oseltamivir phosphate (OP) that were 5-6 fold, 20-30 fold, and 600-800 fold above the therapeutic peak were tested, as neither OP nor its active metabolite, oseltamivir carboxylate (OC), could be detected at near-therapeutic concentrations. The transplacental transfer and accumulation of OC were assessed using the (14)C antipyrine reference method. RESULTS: OP was extensively metabolized to OC. In the 4 placentas with the highest concentration of OP, OC had a mean clearance index of 0.13 +/- 0.08, suggesting that transplacental passage occurs at a relatively low rate. Measurable fetal accumulation occurred in the two placentas with the highest initial concentrations. CONCLUSIONS: Oseltamivir phosphate was extensively metabolized in the ex vivo model. Transplacental transfer of the metabolite was incomplete and accumulation was minimal.

    Title Catalytic Asymmetric Synthesis of Allylic Thiol Derivatives.
    Date June 2008
    Journal Organic Letters
    Excerpt

    The palladium(II) complex [(Rp,S)-COP-Cl]2 and its enantiomer catalyze the rearrangement of linear prochiral O-allyl carbamothioates under mild conditions to provide branched S-allyl carbamothioates in high yield and high enantiomeric purity.

    Title Synthesis of an A-e Gambieric Acid Subunit with Use of a C-glycoside Centered Strategy.
    Date July 2007
    Journal Organic Letters
    Excerpt

    This paper describes our synthesis of the A-E subunit of gambieric acid (GA) in addition to the synthesis of the A-ring and the C-E tricycle. The use of an enol ether-olefin RCM strategy to couple the A and C-E subunits and, in the process, generate the B-ring is noteworthy.

    Title The Role of Asynchronous Bond Formation in the Diastereoselective Epoxidation of Cyclic Enol Ethers: a Density Functional Theory Study.
    Date June 2007
    Journal The Journal of Organic Chemistry
    Excerpt

    Density functional theory (DFT) (Becke3LYP functional and the D95 basis set) was used to study the influence of substitution on the dimethyldioxirane epoxidation reaction of six- and seven-membered cyclic enol ethers. In agreement with our previously reported experimental results, the calculations predict that substitution on the cyclic enol ether influences the level of diastereoselectivity. Apparent only from the calculations is that the degree of synchronicity in the transition state is important in the diastereoselectivity.

    Title The Incidence of Neonatal Herpes Infection.
    Date May 2007
    Journal American Journal of Obstetrics and Gynecology
    Excerpt

    OBJECTIVE: The incidence of perinatal transmission of neonatal herpes infection has recently been reported at 1 in 3200 births. The main objective of this study was to determine a population-based incidence of neonatal herpes simplex virus infection. STUDY DESIGN: This was a retrospective chart review of newborn infants presenting with herpes infection established by cerebrospinal fluid polymerase chain reaction or lesion culture between 1999 and 2003. Only infants delivered at our institution were considered to establish a population-based incidence. RESULTS: Four cases of neonatal herpes infection were identified based on polymerase chain reaction and culture diagnosis. During the study period 78,115 infants were delivered at our institution yielding an incidence of 1 in 20,000 live births. CONCLUSION: The incidence of neonatal herpes infection at our institution is lower than reported elsewhere. A national surveillance program of neonatal herpes is needed to measure the burden of disease across the United States.

    Title Children with Autism: Effect of Iron Supplementation on Sleep and Ferritin.
    Date May 2007
    Journal Pediatric Neurology
    Excerpt

    To determine if there is a relationship between low serum ferritin and sleep disturbance in children with autism spectrum disorder, an 8-week open-label treatment trial with oral iron supplementation was conducted as a pilot study. At baseline and posttreatment visits, parents completed a Sleep Disturbance Scale for Children and a Food Record. Blood samples were obtained. Thirty-three children completed the study. Seventy-seven percent had restless sleep at baseline, which improved significantly with iron therapy, suggesting a relationship between sleep disturbance and iron deficiency in children with autism spectrum disorder. Sixty-nine percent of preschoolers and 35% of school-aged children had insufficient dietary iron intake. Mean ferritin increased significantly (16 microg/L to 29 microg/L), as did mean corpuscular volume and hemoglobin, suggesting that low ferritin in this patient group resulted from insufficient iron intake. Similar prevalence of low ferritin at school age as preschool age indicates that children with autism spectrum disorder require ongoing screening for iron deficiency.

    Title Ferritin As an Indicator of Suspected Iron Deficiency in Children with Autism Spectrum Disorder: Prevalence of Low Serum Ferritin Concentration.
    Date January 2007
    Journal Developmental Medicine and Child Neurology
    Title Valacyclovir Prophylaxis to Prevent Recurrent Herpes at Delivery: a Randomized Clinical Trial.
    Date August 2006
    Journal Obstetrics and Gynecology
    Excerpt

    OBJECTIVE: To measure the efficacy of valacyclovir suppression in late pregnancy to reduce the incidence of recurrent genital herpes in labor and subsequent cesarean delivery. METHODS: A total of 350 pregnant women with a history of genital herpes were assigned randomly to oral valacyclovir 500 mg twice a day or an identical placebo from 36 weeks of gestation until delivery. In labor, vulvovaginal herpes simplex virus (HSV) culture and polymerase chain reaction (PCR) specimens were collected. Vaginal delivery was permitted if no clinical recurrence or prodromal symptoms were present. Neonatal HSV cultures and laboratory tests were obtained, and infants were followed up for 1 month after delivery. Data were analyzed using chi2 and Student t tests. RESULTS: One hundred seventy women treated with valacyclovir and 168 women treated with placebo were evaluated. Eighty-two percent of the women had recurrent genital herpes; 12% had first episode, nonprimary genital herpes; and 6% had first episode, primary genital herpes. At delivery, 28 women (8%) had recurrent genital herpes requiring cesarean delivery: 4% in the valacyclovir group and 13% in the placebo group (P = .009). Herpes simplex virus was detected by culture in 2% of the valacyclovir group and 9% [corrected] of the placebo group (P =.02). No infants were diagnosed with neonatal HSV, and there were no significant differences in neonatal complications. There were no significant differences in maternal or obstetric complications in either group. CONCLUSION: Valacyclovir suppression after 36 weeks of gestation significantly reduces HSV shedding and recurrent genital herpes requiring cesarean delivery. LEVEL OF EVIDENCE: I.

    Title Effect of Protease Inhibitor Therapy on Glucose Intolerance in Pregnancy.
    Date June 2006
    Journal Obstetrics and Gynecology
    Excerpt

    OBJECTIVE: To determine if protease inhibitor use was associated with increased glucose intolerance in our population of pregnant women infected with the human immunodeficiency virus (HIV). METHODS: Women who were infected with HIV from January 1, 1998, to January 8, 2004, and who had a 1-hour and 3-hour glucola test were identified. Medical records were reviewed to obtain demographic characteristics and obstetric and laboratory data. Drug regimens at the time of glucola testing were determined. Human immunodeficiency virus-infected women were then matched 1:3 to HIV-noninfected gravidas by race, age, and year of delivery. RESULTS: One hundred seventy-one HIV-infected women had glucola results available. Twelve percent had an abnormal 1-hour glucola result and 3% had an abnormal 3-hour result. This was similar to the HIV-noninfected population. Forty-five percent of the HIV-infected cohort was on a protease inhibitor at the time of glucola testing. Protease inhibitor exposure had no effect on glucola test results. HIV infection itself also did not increase abnormal glucola test results. CONCLUSION: Glucose intolerance in this obstetric population was not associated with the diagnosis of HIV or with the use of protease inhibitors. Protease inhibitors should continue to be an option for the treatment of HIV in pregnancy.

    Title Substitution and Remote Protecting Group Influence on the Oxidation/addition of Alpha-substituted 1,2-anhydroglycosides: a Novel Entry into C-ketosides.
    Date December 2005
    Journal Organic Letters
    Excerpt

    [reaction: see text] C-Ketosides are valuable intermediates in chemical synthesis and as glycoside mimics. This manuscript describes the efficient generation of these substrates from alpha-alkyl-substituted glycals and an oxidative, C-C bond-forming sequence where the choice of C(3) protecting group was critical.

    Title Screening Electroencephalograms in Autism Spectrum Disorders: Evidence-based Guideline.
    Date June 2005
    Journal Journal of Child Neurology
    Excerpt

    The purpose of this study was to establish guidelines for the use of screening electroencephalograms (EEGs) in autism spectrum disorders to identify subclinical epileptiform activity. MEDLINE and EMBASE were searched for relevant articles. The evidence was reviewed using the methodology of the Canadian Task Force on Preventive Health Care. A priori criteria were established for article selection and for grading the quality and strength of the evidence. Seizures are common, occurring in 20 to 30% of patients based on the majority of studies. Epileptiform EEG abnormalities are present in 10.3% to 72.4% of patients and subclinical abnormalities in 6.1% to 31%. Evidence for the effectiveness of anticonvulsants and corticosteroids in reducing seizures and/or autistic symptoms is based primarily on case series and case reports, with only one published randomized trial. There is currently insufficient evidence to recommend for or against the use of screening EEGs in autistic patients. Given the frequency of seizure disorders in this patient population, a high index of clinical suspicion should be maintained for subtle symptoms of seizures.

    Title The Effectiveness of Infant Simulators.
    Date April 2005
    Journal Adolescence
    Excerpt

    This study investigated the effect of using infant simulators with a structured, competency-based curriculum by examining the infant care behavior of adolescents and their attitudes toward parenting and sexual behavior. The sample of 236 students included 112 males and 124 females ranging in age from 14 to 18 years. This sample was randomly assigned to an experimental group of 174 and a control group of 62. The experimental group completed the New York State parenting curriculum, which focused on reflection-based parenting skills with specific childcare competencies. The findings indicate that the infant simulator is an effective tool for teaching childcare skills. When combined with a well-designed curriculum, it enhances the likelihood that student attitudes toward sexuality/parenting issues can be significantly modified.

    Title False Positive Results for the Auszyme Monoclonal Test.
    Date March 2005
    Journal Obstetrics and Gynecology
    Title Evaluating the Effects of Elevated Levels of Atmospheric Trace Gases on Herbs and Shrubs: a Prototype Dual Array Field Exposure System.
    Date January 2005
    Journal Environmental Pollution (barking, Essex : 1987)
    Excerpt

    In the context of global climate change, an understanding of the long-term effects of increasing concentrations of atmospheric trace gases (carbon dioxide, CO(2), ozone, O(3), oxides of nitrogen, NO(x) etc.) on both cultivated and native vegetation is of utmost importance. Over the years, under field conditions, various trace gas-vegetation exposure methodologies with differing advantages and disadvantages have been used. Because of these variable criteria, with elevated O(3) or CO(2) levels, at the present time the approach of free-air experimental-release of the gas into study plots is attracting much attention. However, in the case of CO(2), this approach (using 15 m diameter study plot with a single circular array of vent pipes) has proven to be cost prohibitive (about 59000-98000 dollars/year/replicate) due to the consumption of significant quantities of the gas to perform the experiment (CO(2) level elevated to 400 ppm above the ambient). Therefore, in this paper, we present a new approach consisting of a dual, concentric exposure array of vertical risers or vent pipes. The purpose of the outer array (17 m diameter) is to vent ambient air outward and toward the incoming wind, thus providing an air curtain to reduce the velocity of that incoming wind to simulate the mode or the most frequently occurring wind speed at the study site. The inner array (15 m diameter) vents the required elevated levels of trace gases (CO(2), O(3), etc.) into the study plot. This dual array system is designed to provide spatial homogeneity (shown through diffusion modeling) of the desired trace-gas levels within the study plot and to also reduce its consumption. As an example, while in the single-array free-air CO(2)-release system the consumption of CO(2) to elevate its ambient concentration by 400 ppm is calculated to be about 980 tons/year/replicate, it is estimated that in the dual array system it would be approximately 590 tons/year/replicate. Thus, the dual array system may provide substantial cost savings (24000-39000 dollars/year/replicate) in the CO(2) consumption (60-100 dollars/ton of CO(2)) alone. Similarly, benefits in the requirements of other trace gases (O(3), NO(x), etc.) are expected, in future multivariate studies on global climate change.

    Title Exploring the Gap Between Knowledge and Behavior: a Qualitative Study of Clinician Action Following an Educational Intervention.
    Date June 2004
    Journal Academic Medicine : Journal of the Association of American Medical Colleges
    Excerpt

    PURPOSE: Many medical education interventions improve clinicians' knowledge but fail to change behavior. The authors exposed this knowledge-behavior gap through standardized clinical interactions, thus allowing in-depth exploration of the contributing factors. METHOD: A typical evidence-based educational intervention in one clinical domain (early signs of autism) was administered to family medicine residents at the University of Toronto in 2001-02, and change in knowledge was assessed through a multiple-choice test. Six to eight weeks later, participants' relevant knowledge was documented, and their clinical behavior was observed during four interactions with standardized patients. Factors producing a knowledge-behavior discrepancy were then explored using semistructured interviews, which were audiotaped, transcribed, and analyzed using grounded theory methods. RESULTS: Half of participants demonstrated varying degrees of knowledge-behavior gap. Eight main rationalizations (relationships, patient agenda, knowledge deficit, clinical style, means to an end, ideals, autism stigma, and systems barriers) were used to justify choices of clinical behavior, and the same rationalizations were used to justify opposite choices of behavior. Two conditions that promote clinical action based on knowledge (level of certainty and sense of urgency) were identified. CONCLUSION: The knowledge-behavior gap was exposed and factors reported to influence clinicians' decisions about whether to implement new knowledge were elicited. That identical rationalizations were used to justify opposite behaviors implies these factors may not be behavioral determinants. Sense of urgency and level of certainty promote clinical action based on knowledge; focusing on these may increase the impact of education on practice.

    Title Obstetric Clavicular Fracture: the Enigma of Normal Birth.
    Date January 1996
    Journal Obstetrics and Gynecology
    Excerpt

    OBJECTIVE: To determine the main risk factors involved in neonatal clavicular fracture, the most common injury to the neonate. METHODS: Two hundred fifteen cases of clavicular fracture of 65,091 vaginal deliveries (0.4%) occurring between January 1983 and December 1988 were pair-matched with controls based on mode and date of delivery, race, and maternal age. Incidences, odds ratios, and stratified analysis were used to identify and control for confounding between risk factors. RESULTS: Shoulder dystocia, increasing birth weight, and increasing gestational age were identified as risk factors. Within the range of normal birth weights, there is a biologic gradient of increasing risk for clavicular fracture. Although shoulder dystocia is the strongest risk factor identified, the magnitude of its point estimate is probably affected to a large extent by differential ascertainment. The use of forceps, prolonged second stage of labor, and nulliparity status were not significantly associated with neonatal clavicular fracture. CONCLUSIONS: Neonatal clavicular fracture occurs commonly in an obstetric population. Obstetric clavicular fracture is an unpredictable, unavoidable complication of normal birth.

    Title Markers of Acute and Chronic Asphyxia in Infants with Meconium-stained Amniotic Fluid.
    Date May 1995
    Journal American Journal of Obstetrics and Gynecology
    Excerpt

    OBJECTIVE: Cord blood pH, lactate, hypoxanthine, and erythropoietin levels have all been used as markers of either acute or chronic asphyxia. We sought to determine whether these index values were significantly different in infants with or without meconium-stained amniotic fluid. STUDY DESIGN: Fifty-six pregnant women in spontaneous labor at term were divided into two groups on the basis of the presence or absence of meconium-stained amniotic fluid. All meconium-stained fluid was centrifuged, and the volume percentage of particulate matter (i.e., meconium) was recorded. Umbilical artery blood and mixed arterial and venous cord blood were obtained at each delivery. Lactate, hypoxanthine, and erythropoietin levels were measured. Statistical analysis included Student t test and rank sum statistics where appropriate. Normal and Spearman correlation coefficients were also used. RESULTS: There were no significant differences in mean umbilical artery pH (7.26 +/- 0.06 vs 7.25 +/- 0.10), lactate levels (32.8 +/- 10 mg/dl vs 30.4 +/- 14.2 mg/dl), and hypoxanthine levels (13.4 +/- 6.7 mumol/L vs 14.0 +/- 6.0 mumol/L) in newborns with meconium (n = 28) compared with controls (n = 28). Erythropoietin levels were significantly greater in newborns with meconium (median 39.5 mIU/ml vs 26.8 mIU/ml, p = 0.039). There was no correlation between the amount of particulate matter and any marker of asphyxia. CONCLUSIONS: There was no correlation between markers of acute asphyxia (i.e., umbilical artery blood pH, lactate, or hypoxanthine) and meconium. However, erythropoietin levels were significantly elevated in newborns with meconium-stained amniotic fluid. This latter marker may better correlate with chronic asphyxia.

    Title The Correlation Between Transperineal Sonography and Digital Examination in the Evaluation of the Third-trimester Cervix.
    Date May 1995
    Journal Obstetrics and Gynecology
    Excerpt

    OBJECTIVE: To determine the correlation between transperineal or translabial ultrasound and digital examination of the cervix in the third trimester in women presenting to the obstetrical triage area complaining of uterine contractions and/or rupture of membranes. METHOD: One hundred women were evaluated initially with an ultrasound unit using a 5-MHz glove-covered curvilinear transducer applied to the perineum in the sagittal plane. Immediately after the ultrasound evaluation, another examiner assessed the cervix digitally, blinded to the sonographic results. Cervical dilatation, length, and station were assessed. RESULTS: Transperineal ultrasound correlated (P < .001) with digital cervical examination in the assessment of dilatation (Pearson correlation coefficient 0.87), length (Pearson correlation coefficient 0.80), and corrected station (Pearson correlation coefficient 0.69). CONCLUSION: There is a statistically significant correlation between the digital cervical examination and the sonographic assessment of cervical dilatation, length, and station by the transperineal approach.

    Title Genital Herpes During Pregnancy: No Lesions, No Cesarean.
    Date February 1995
    Journal Obstetrics and Gynecology
    Excerpt

    OBJECTIVE: To determine the effects at our hospital of adoption of the 1988 guidelines recommended by ACOG for management of genital herpes infections during pregnancy. METHODS: Between 1984-1986, 96 pregnancies complicated by active genital herpes were delivered at Parkland Hospital. The outcome of these pregnancies were compared with 217 similar pregnancies managed after implementation of the 1988 ACOG herpes guidelines. RESULTS: Adoption of the 1988 ACOG herpes guidelines resulted in a 37% decrease in the use of cesarean delivery for women with genital herpes infections at our hospital. Most of this decrease was because the new guidelines eliminated the need for a confirmatory negative herpes culture before permitting vaginal delivery. No neonatal herpes infections occurred as a result of implementing the ACOG recommendations. CONCLUSION: The rate of cesarean delivery for women with genital herpes infections during pregnancy declined significantly at our hospital as a result of the adoption of ACOG herpes guidelines, and there were no neonatal consequences, such as increased incidence of neonatal herpes simplex virus infection.

    Title Fetal Acidemia Associated with Regional Anesthesia for Elective Cesarean Delivery.
    Date January 1995
    Journal Obstetrics and Gynecology
    Excerpt

    OBJECTIVE: To determine the prevalence, magnitude, and type of fetal acidemia associated with contemporary obstetric anesthetic techniques. METHODS: Umbilical artery blood gases were obtained in 1601 singleton pregnancies delivered by elective cesarean. RESULTS: General anesthesia was used in 371 (23%) women, epidural in 286 (18%), combined spinal-epidural in 659 (41%), and spinal in 231 (14%). Approximately 18% of infants exposed to regional anesthetics had umbilical artery blood pH values 7.19 or less, 42 (3%) infants had pH values less than 7.10, and nine (1%) had values 6.99 or less. The incidence of fetal acidemia was greater in spinal and combined spinal-epidural procedures compared to epidural anesthetics. Fetal acidemia was predominantly respiratory in type because carbon dioxide pressure was abnormally increased when fetal acidemia was diagnosed. CONCLUSIONS: Regional anesthesia is associated with fetal acidemia, occasionally severe, and has features of an acute respiratory type of acidemia. Fetal acidemia is less frequent with epidural anesthesia compared to subarachnoid techniques.

    Title Pneumonia Complicating Pregnancy.
    Date October 1994
    Journal Obstetrics and Gynecology
    Excerpt

    OBJECTIVE: To determine the clinical course and perinatal outcomes of women with pneumonia complicating pregnancy. METHODS: Between 1989 and 1993, we admitted 71 pregnant women for treatment of community-acquired pneumonia. Exposure and outcome variables as well as characteristics of their clinical course were identified and analyzed. Two-sample Wilcoxon rank-sum and Fisher exact tests were used for statistical analyses. RESULTS: Five women had adverse pregnancy outcomes related to pneumonia: two maternal-fetal deaths, one preterm delivery, one fetal death, and one early abortion. Compared with women whose pregnancies went to term, these five women had a significantly lower mean oxygen pressure on admission (68 versus 83 mmHg). Other risk factors for adverse outcome included diffuse radiologic pulmonary involvement and current smoking of more than ten cigarettes per day. Neither illicit drug use nor anemia were risk factors. Although 31 of these 71 women had underlying chronic diseases, these were not associated with negative outcomes. CONCLUSIONS: Despite prompt hospitalization and treatment, antepartum pneumonia is potentially serious, even in young, otherwise healthy women. Although underlying maternal disease appears to be related to the development of antepartum pneumonia, we did not confirm previous reports that suggested its relation to adverse pregnancy outcome.

    Title The Transfer of the Nucleoside Analog Ganciclovir Across the Perfused Human Placenta.
    Date May 1994
    Journal American Journal of Obstetrics and Gynecology
    Excerpt

    OBJECTIVE: The purpose of this study was to compare the maternal-fetal placental transfer of the antiviral nucleoside analog ganciclovir to that of acyclovir and to investigate the mechanism of transport. STUDY DESIGN: The ex vivo human placental cotyledon model was used. Carbon 14-labeled antipyrine was used as the reference compound to determine the clearance index of both antiviral agents. Dinitrobenzylthioinosine was used as a nucleoside transport inhibitor to help determine the transfer mechanism of each agent. RESULTS: The clearance index for ganciclovir was 0.17 +/- 0.08 and 0.20 +/- 0.10 at 1 and 10 micrograms/ml maternal concentrations. This was similar to the clearance index for acyclovir, which was 0.17 +/- 0.06 and 0.18 +/- 0.12, respectively. The clearance index for ganciclovir was not significantly affected by the addition of 5 mumol/L dinitrobenzylthionosine to the perfusate (0.25 +/- 0.09 vs 0.20 +/- 0.05). The same was true for acyclovir (0.29 +/- 0.06 vs 0.22 +/- 0.07). When the closed system and maternal ganciclovir concentrations of 1.0, 10.0, and 100 micrograms/ml were used, the percent fetal levels compared with maternal levels at 1 hour were 17.2%, 19.2%, and 17.3%, respectively. For acyclovir the fetal levels were 15.6%, 9.1%, and 8.9% compared with maternal levels. CONCLUSION: The antiviral agents ganciclovir and acyclovir appear to cross the placenta by simple diffusion, at least at therapeutic levels, and this transfer is not affected by the nucleoside transport inhibitor dinitrobenzylthioinosine.

    Title Food First, Educating Our Children.
    Date March 1990
    Journal Health Education
    Title Job Satisfaction Among Paramedics.
    Date November 1987
    Journal Jems : a Journal of Emergency Medical Services
    Title Pk1' and Bicarbonate Concentration in Plasma.
    Date February 1987
    Journal Clinical Chemistry
    Excerpt

    Values for pK1' were determined from pH measured at 37 degrees C with three blood-gas analyzers and from calculated pco2 values in 443 freshly separated plasmas, tonometered at 37 degrees C. Plasma was taken from healthy volunteers, seriously ill patients, and hyponatremic patients. pK1' values varied by considerably more than 0.06 in healthy volunteers as well as in very ill patients, and bicarbonate concentrations ([HCO3]p) calculated by blood-gas analyzers based on the pK1' value of 6.1 could be in error by some +/- 60%. pK1' was similarly determined for tonometered (37 degrees C) replicate dilutions of plasma samples. By adding weighed amounts of dry NaCl and NaHCO3 to the diluted samples we increased the Na+ concentration to approximately 150 mmol/L and bicarbonate concentrations to values ranging from approximately 2.5 to approximately 52.5 mmol/L. pK1' values decreased when [HCO3]p was increased in dilutions of plasma kept at constant ionic strength. At any given [HCO3]p, pK1' values were higher at high than at low values of pco2.

    Title Practical Nursing Care of Children with Intracranial Tumours.
    Date June 1967
    Journal Nursing Times
    Title Physiological Adjustment of Two Full-sib Families of Ponderosa Pine to Elevated Co(2).
    Date
    Journal Tree Physiology
    Excerpt

    Seeds from two full-sib families of ponderosa pine (Pinus ponderosa) with known differences in growth rates were germinated and grown in an ambient (350 micro l l(-1)) or elevated (700 micro l l(-1)) CO(2) concentration. Gas exchange at both ambient and elevated CO(2) concentrations was measured 1, 6, 39, and 112 days after the seed coat was shed. Initial stimulation of CO(2) exchange rate (CER) by elevated CO(2) was large (> 100%). On Day 1, CER of seedlings grown in elevated CO(2) and measured at ambient CO(2) was significantly lower than the CER of seedlings grown and measured at ambient CO(2), indicating physiological adjustment of the seedlings exposed to elevated CO(2). Physiological acclimation to elevated CO(2) was complete by Day 39 when there was no significant difference in CER between seedlings grown and measured at ambient CO(2) and seedlings grown and measured at elevated CO(2). After 4 months, the light response of seedlings in the two treatments was determined at both ambient and elevated CO(2). Light compensation point, CER at light saturation, and apparent quantum efficiency of seedlings grown and measured at ambient CO(2) were not significantly different from those of seedlings grown and measured at elevated CO(2). With a short-term increase in CO(2), CER at light saturation (5.16 +/- 0.52 versus 3.13 +/- 0.30 micro mol CO(2) m(-2) s(-1)) and apparent quantum efficiency (0.082 +/- 0.011 versus 0.045 +/- 0.003 micro mol CO(2) micro mol(-1) quanta) were significantly increased. Leaf C/N ratio was significantly increased in the elevated CO(2) treatment. There were few significant differences between families for any response to elevated CO(2). Under the experimental conditions, high growth rate was not correlated with a greater response to elevated CO(2).

    Title In Situ Estimates of Variable Plant Resistance to Water Flux in Ilex Opaca Ait.
    Date
    Journal Plant Physiology
    Excerpt

    Xylem pressure potentials and stomatal diffusion resistances were measured in the field in Ilex opaca Ait. during days which differed in temperature and vapor pressure deficit. Water flux into leaves was calculated by combining the field data with laboratory determinations of the relation between tissue water deficit and water potential. Estimates of apparent plant resistance were then calculated from fluxes and differences between soil water potential and xylem tension. The resistance depended strongly on water flux, dropping by a factor of over 7 from low to high water flow rates. This extends the generality of variable plant resistances measured in controlled environment studies to I. opaca as it occurs naturally in the field. The relation of apparent plant resistance to water flux as estimated in this study can be useful in simulation models which calculate water uptake to leaves as a flux driven by a difference in soil and leaf water potentials across a resistance between the bulk soil and the leaf.

    Title Chorioamnionitis: Association of Nonreassuring Fetal Heart-rate Patterns and Interval From Diagnosis to Delivery on Neonatal Outcome.
    Date
    Journal Infectious Diseases in Obstetrics and Gynecology
    Excerpt

    Objective: The purpose of this study was to determine whether selected fetal heart-rate (FHR) patterns and the interval from diagnosis to delivery in pregnancies complicated by chorioamnionitis could predict neonatal outcome.Methods: During a 6-month period, 217 consecutive patients with acute chorioamnionitis were prospectively identified in labor. Following delivery, the fetal monitor strips and hospital courses were reviewed for both the mother and neonate. Multiple logistic regression was used to analyze the presence of a nonreassuring FHR pattern and the effect on neonatal outcome. Fisher exact tests were used to analyze the time intervals from the diagnosis of chorioamnionitis to delivery and their significance on neonatal outcome parameters.Results: The overall incidence of chorioamnionitis in our population was 2.3%. None of the independent variables analyzed following the diagnosis of chorioamnionitis until delivery were significantly associated with an umbilical artery (Ua) pH < 7.20. There were no differences in cord pH, Apgar scores, sepsis, admission to special-care nursery, and oxygen requirements in neonates based on the duration of time from the diagnosis of chorioamnionitis to delivery in our study. None of the newborns had pathologic fetal acidemia (Ua pH < 7.00). None of the FHR patterns we identified after the diagnosis of acute chorioamnionitis were significantly associated with neonates with a Ua pH < 7.20.Conclusions: An interval from diagnosis to delivery of up to 12 h plays little if any role in neonatal outcome.

    Title Urine Screening for Chlamydia Trachomatis During Pregnancy.
    Date
    Journal Obstetrics and Gynecology
    Excerpt

    To compare the rates of Chlamydia trachomatis detection using urine and cervical secretions from pregnant women at our institution.

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