Michael O Gardner

University of Texas Health Science Center at Houston, Houston, TX, United States

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Publications (19)27.44 Total impact

  • [show abstract] [hide abstract]
    ABSTRACT: Thrombophilias have been implicated in complications related to ischemic placental disease including recurrent pregnancy loss, intrauterine fetal demise, preeclampsia, fetal growth restriction, placental abruption, and preterm delivery. Maternal screening and treatment may lower the recurrence of these outcomes. Our objective was to estimate if antenatal screening for thrombophilias with the intention to offer treatment among women with a prior adverse pregnancy outcome (APO) is preferable to no screening. A decision-analytical model was constructed for pregnant women with prior APO, comparing screening for thrombophilia with intention to treat with no screening. Values obtained from previously published studies include probability of positive test: 0.3 (0.1 to 0.6); good outcome with treatment: 0.9 (0.3 to 0.99); no thrombophilia, good outcome: 0.75 (0.5 to 0.9); test negative, thrombophilia positive: 0.05 (0.01 to 0.1); test negative, thrombophilia positive, good outcome: 0.75 (0.5 to 0.9); thrombophilia/test negative, good outcome: 0.98 (0.5 to 0.99). Sensitivity analyses were run over a wide range of assumptions. Thrombophilia screening with intention to treat in women with prior APO associated with ischemic placental disease is the strategy of choice compared with no testing over a wide range of assumptions. Sensitivity analyses support this to be robust. Women with poor pregnancy history related to placental ischemic disease may benefit from thrombophilia screening and treatment in a subsequent pregnancy.
    American Journal of Perinatology 03/2011; 28(6):495-500. · 1.57 Impact Factor
  • Anna Gonzalez, Michael Gardner, Nora Doyle
    American Journal of Obstetrics and Gynecology - AMER J OBSTET GYNECOL. 01/2009; 201(6).
  • Michael Gardner, Nora Doyle
    American Journal of Obstetrics and Gynecology - AMER J OBSTET GYNECOL. 01/2007; 197(6).
  • Nora M Doyle, Judy E Levison, Michael O Gardner
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    ABSTRACT: Mother-to-child transmission of human immunodeficiency virus is the most common cause of pediatric human immunodeficiency virus in the United States; the Centers for Disease Control and Prevention recommendations endorse rapid human immunodeficiency virus testing for women with unknown viral status to quicken antiretroviral therapy. We compared the cost-effectiveness of Oraquick (Orasure Technologies, Bethlehem, Pa) rapid testing versus enzyme-linked immunosorbent assay testing for a low-risk population of Mexican American women who are in labor. Using decision analysis techniques, we tested 2 strategies: (1) testing with enzyme-linked immunosorbent assay that was confirmed by Western blot and (2) testing with Oraquick rapid testing that was confirmed by Western blot. All seropositive parturients received zidovudine treatment in labor. The baseline assumptions were the incidence of human immunodeficiency virus in Mexican American mothers (0.05%), mother-to-child transmission with no treatment (25%), with treatment in labor (10%), sensitivity of enzyme-linked immunosorbent assay (98%), positive predictive value of enzyme-linked immunosorbent assay (10%), sensitivity/specificity of Oraquick rapid testing (99%/100%), positive predictive value of Oraquick rapid testing (83%-100%), sensitivity/specificity of Western blot (97%/99%), costs (enzyme-linked immunosorbent assay [dollar 5], Oraquick rapid testing [dollar 15], Western blot [dollar 25], zidovudine treatment [dollar 76] for 12 hours labor, neonatal treatment [dollar 2.50], lifetime treatment of human immunodeficiency virus-affected child [dollar 194,250]). Sensitivity analyses were done over a wide range of assumptions that included the costs of tests, the sensitivity of Oraquick rapid testing, the positive predictive value of enzyme-linked immunosorbent assay and Oraquick rapid testing, and the costs of treatments. Oraquick rapid testing was the preferred strategy at dollar 98 spent per human immunodeficiency virus-negative child versus dollar 491 for enzyme-linked immunosorbent assay testing. Much of the cost of the enzyme-linked immunosorbent assay strategy was due to the treatment of women and infants with false-positive tests. Sensitivity analysis over test costs, test sensitivity, and other variables found the analysis results to be robust. Threshold analysis revealed that, if the cost remained < dollar 409.90, Oraquick rapid testing was the dominant test. In a low prevalence population, the universal use of Oraquick rapid testing is cost-effective because of the low rate of false-positive results, thus preventing the emotional and economic costs of unnecessary treatment for human immunodeficiency virus to the new mother and her family.
    American Journal of Obstetrics and Gynecology 10/2005; 193(3 Pt 2):1280-5. · 3.88 Impact Factor
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    ABSTRACT: Beginning in October 1995, and for several years thereafter, our institution used indomethacin as a first-line tocolytic drug. Our purpose is to compare the outcomes of very low birth weight infants who were exposed to antenatal indomethacin with those who were not exposed to this therapy. We used our center's component of the NICHD Neonatal Research Network's Generic Data Base which recorded the outcomes of all live born infants weighing less than 1500 g over a 5-year period. We abstracted data concerning neonatal morbidity (death, Grades III to IV intraventricular hemorrhage (IVH), necrotizing enterocolitis and patent ductus arteriosus), as well as other factors including gestational age, birth weight, antenatal corticosteroid treatment and maternal hypertension or pre-eclampsia. Univariate analysis was performed using Fisher's exact test. Multivariate analysis using logistic regression was performed to control for confounding factors. A total of 85 infants who were exposed to antenatal indomethacin were compared to 464 infants who were not exposed to the drug. In the univariate analysis, antenatal indomethacin exposure was not associated with a significant increase in the incidence of necrotizing enterocolitis or patent ductus arteriosus. The incidence of Grades III to IV IVH was 17.9% in those infants exposed to antenatal indomethacin compared to 7.1% in the nonexposed infants (p=0.008). The incidence of neonatal death in the exposed infants was 27.7 versus 16.4 in the nonexposed infants (p=0.02). After controlling for antenatal corticosteroids, maternal pre-eclampsia, gestational age and birth weight, antenatal indomethacin was significantly associated with an increased incidence of IVH, but not neonatal death. Antenatal indomethacin was associated with significantly higher rates of IVH. Additional studies assessing the potential risks of indomethacin tocolysis are needed before it is used as a first-line tocolytic therapy.
    Journal of Perinatology 06/2005; 25(5):336-40. · 2.25 Impact Factor
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    ABSTRACT: To identify the characteristics of the gravidas delivering at our birthing center that place them at risk for false-positive human immunodeficiency virus (HIV) enzyme-linked immunosorbent assay (ELISA). The medical records of all rapid HIV-ELISA-positive gravidas that delivered at our hospital between January 2000 and October 2001 were retrieved, and information was gathered regarding maternal demographics. The results of the Western blot tests were also retrieved and correlated to the ELISA results, across varying maternal characteristics. chi(2), Student's t-test and multivariate analysis were performed, as appropriate, using the SAS software; statistical significance was denoted by p<0.05. A total of 69 patients had a positive rapid HIV-ELISA out of 9,781 deliveries. Of those, 26 were confirmed as HIV infected by Western blot (overall HIV prevalence: 0.27%, ELISA-positive predictive value: 37.7%). The subgroup prevalence of HIV and positive predictive value of ELISA were 1.53 and 75% among Caucasians; 2.43 and 82.6% among African-Americans; and 0.05 and 9.8% among Hispanics, respectively (p<0.05 for the comparisons between Hispanics and non-Hispanics only). A history of multiple (> or =5 lifetime) sexual partners was elicited in the majority of HIV-infected patients. The positive predictive value of rapid HIV-ELISA during pregnancy varies widely, depending on maternal race/ethnicity and sexual behavior. The routine disclosure of rapid intrapartum HIV serum screening results prior to Western blot confirmation should be avoided in very low-risk populations.
    Journal of Perinatology 01/2005; 24(12):743-7. · 2.25 Impact Factor
  • Antara Mallampalli, David J Powner, Michael O Gardner
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    ABSTRACT: Cardiopulmonary arrest during pregnancy is a rare event that critical care clinicians must be prepared to manage. The causes of cardiopulmonary arrest during pregnancy, recommended modifications to cardiopulmonary resuscitation protocols that are specific to pregnancy, indications for and timing of perimortem cesarean delivery, and the expected fetal outcomes are reviewed. Rarely, brain death of a pregnant patient may occur in which continued support of the mother is possible to prolong the pregnancy and improve fetal outcome. Prolonged somatic support of pregnant patients who are brain dead presents specific management challenges, but has been accomplished. The physiologic changes that occur after brain death and recommendations for somatic support of the brain dead pregnant patient also are reviewed.
    Critical Care Clinics 11/2004; 20(4):747-61, x. · 1.95 Impact Factor
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    ABSTRACT: Mother-to-child transmission of HIV (MTCT) is a major contributor to Zambia's HIV burden. Based on our experience in Zambia, we felt that provider perceptions, knowledge base, and practice patterns toward HIV-positive mothers may pose as significant obstacles to preventing MTCT. Two hundred and twenty-five health care providers throughout Zambia were surveyed in 2002. Providers reported widespread stigma associated with HIV. Physicians (OR = 1.9), providers with research affiliations (OR = 2.3), and those located in Lusaka (OR = 9.0) were more likely to offer HIV testing. Only 30% routinely prescribed antiretroviral treatment (ART) to reduce MTCT. Practitioners from district facilities, those from Lusaka, and those employed at research facilities were more likely to prescribe ART routinely (OR = 2.8, 10.1 and 3.4 respectively). Among those never prescribing ART, most cited a lack of availability (83%). Our results highlight the need for further provider education, critical appraisal of the current system for HIV testing, and widespread distribution of ART.
    International Journal of STD & AIDS 11/2004; 15(10):685-90. · 1.00 Impact Factor
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    ABSTRACT: Pulmonary embolism is a major cause of maternal death. The work up for suspected pulmonary embolism is complex, with many potential diagnostic options. We performed a cost analysis to evaluate which of several diagnostic strategies was the most cost-effective with the least number of deaths from pulmonary embolism. We created a decision tree to evaluate the following strategies: (1) Compression ultrasonography followed by anticoagulation (if there is a positive result) or secondary tests, ventilation perfusion scans or spiral computed tomography (if there is a negative result); high probability ventilation perfusion scans (a positive test result) resulted in anticoagulation; low probability ventilation perfusion scans (a negative test) resulted in no treatment; intermediate tests that resulted in a second test (computed tomography or pulmonary angiography). (2) Ventilation perfusion scans as a primary test followed by anticoagulation. (3) Computed tomography followed by anticoagulation (if there is a positive result). The following assumptions were made: The incidence of pulmonary embolism in pregnant women with suspected pulmonary embolism is 5%; 40% of documented pulmonary embolisms have a positive compression ultrasound result; 10% of ventilation perfusion scans for suspected pulmonary embolism are high probability, 60% are indeterminate, and 30% are low probability for pulmonary embolism; the sensitivity of computed tomography is 95%; the sensitivity of angiography is 98%. The assumed mortality rate of treated pulmonary embolism is 0.7% and of untreated pulmonary embolism in pregnancy is 15% (range, 10%-50%). The angiography-associated mortality rate is 0.5%, and the anticoagulation associated mortality rate is 0.2%. The following costs were used for the model: compression ultrasonography, 200.00 dollars; ventilation perfusion scans, 400.00 dollars; angiography, 1000.00 dollars; computed tomography, 500.00 dollars; and anticoagulation, 5982.00 dollars. With baseline assumptions, spiral computed tomography as the initial diagnostic regimen was found to be the most cost-effective at 17,208 dollars per life saved. Sensitivity analyses were performed over a wide range of assumptions that included alteration of the probability of pulmonary embolism, the sensitivity of computed tomography, ventilation perfusion scans, and compression ultrasonography, the cost of computed tomography, and the mortality rate of untreated pulmonary embolism. Our findings remained robust over a wide range of assumptions. Suspected pulmonary embolism remains a diagnostic quandary. Our analysis indicated that spiral computed tomography offers the most cost-effective method for diagnosing this potentially fatal condition.
    American Journal of Obstetrics and Gynecology 10/2004; 191(3):1019-23. · 3.88 Impact Factor
  • Michael O Gardner, Nora M Doyle
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    ABSTRACT: Asthma is a chronic inflammatory disease of the airway system that is characterized by bronchoconstriction and bronchial hyperresponsiveness that are triggered by a host of stimuli. Asthma is the most common respiratory disease in pregnancy and affects approximately 4% of pregnant women. This article reviews asthma as a public health concern, the normal physiology of pregnancy,the pathophysiology of asthma in pregnancy, the effects of asthma on pregnancy and pregnancy on asthma, objective lung function testing, goals for the pregnant woman who has asthma, and treatment of chronic and acute episodes of asthma.
    Obstetrics and Gynecology Clinics of North America 07/2004; 31(2):385-413, vii. · 1.45 Impact Factor
  • Michael O. Gardner, Manju Monga
    Obstetrics and Gynecology Clinics of North America 06/2004; 31(2):xi–xii. · 1.45 Impact Factor
  • Nora Doyle, Michael Gardner
    American Journal of Obstetrics and Gynecology - AMER J OBSTET GYNECOL. 01/2004; 191(6).
  • American Journal of Obstetrics and Gynecology - AMER J OBSTET GYNECOL. 01/2004; 191(6).
  • Nora Doyle, Judy Levison, Michael Gardner
    American Journal of Obstetrics and Gynecology - AMER J OBSTET GYNECOL. 01/2004; 191(6).
  • Nora M Doyle, Michael O Gardner
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    ABSTRACT: We evaluated the cost benefit of cystic fibrosis screening in Mexican American gravid women. With the use of decisions analysis techniques, a cost-benefit analysis was performed. Baseline assumptions were based on published references. Sensitivity analyses were performed. Under the baseline assumptions, screening was not cost beneficial. Threshold analysis showed that, if the test was priced under 53.00 dollars, screening became cost beneficial. Sensitivity analysis demonstrated that lower acceptance rates of amniocentesis or termination made the screening strategy less attractive. If the test sensitivity was raised to 90%, which required testing of >60 mutations, the cost of screening would need to be <100.00 dollars for the program to be cost beneficial. Cystic fibrosis screening is not cost beneficial in Mexican American women over a wide range of assumptions. This is principally due to the poor sensitivity of the test in this population. Cultural factors, such as lower acceptance of amniocentesis and pregnancy termination of affected fetuses, further lower the cost-benefit ratio of screening.
    American Journal of Obstetrics and Gynecology 09/2003; 189(3):769-74. · 3.88 Impact Factor
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    ABSTRACT: Length of sperm exposure has been proposed to influence the risk of preeclampsia. The main objective was to determine the relationship between extent of exposure to sperm, both before and during pregnancy, and the risk of preeclampsia. A case-control design was used where women with preeclampsia (cases) were matched with two women without preeclampsia (controls) by age and parity. Data were analyzed by Student t test, chi(2) test, and logistic regression analysis. A total of 113 cases were compared with 226 controls. Women with a short period of cohabitation (<4 months) who used barrier methods for contraception had a substantially elevated risk for development of preeclampsia compared with women with more than 12 months of cohabitation before conception (odds ratio 17.1, P =.004). Fewer than 4 months of cohabitation among users of barrier methods for contraception is associated with a significantly increased risk for preeclampsia.
    American Journal of Obstetrics and Gynecology 06/2003; 188(5):1241-3. · 3.88 Impact Factor
  • American Journal of Obstetrics and Gynecology - AMER J OBSTET GYNECOL. 01/2003; 189(6).
  • Nora Doyle, Paul Fine, Michael Gardner
    American Journal of Obstetrics and Gynecology - AMER J OBSTET GYNECOL. 01/2003; 189(6).
  • Obstetrics and Gynecology - OBSTET GYNECOL. 01/2002; 99(4).

Publication Stats

112 Citations
1 Download
631 Views
27.44 Total Impact Points

Institutions

  • 2003–2005
    • University of Texas Health Science Center at Houston
      • Department of Obstetrics, Gynecology and Reproductive Sciences
      Houston, TX, United States
    • Baylor College of Medicine
      • Department of Obstetrics and Gynecology
      Houston, TX, United States