Photo of Antonio E. Frias, M.D.

Antonio E. Frias M.D.

Dr. Frias has a special interest in diabetes mellitus, thrombophilias, recurrent pregnancy loss and fetal anemia (RH disease). His current research focuses on placental development, obesity and nutrition. Dr. Frias finds it rewarding to educate patients about their health and help them in making the best health care decisions. He enjoys providing medical care throughout complicated pregnancies so that his patient can have an optimal outcome as well as a good experience.

Born in Houston, Texas, Dr. Frias loves living the Pacific Northwest. He's happy to be in Portland because he finds it to be a blend of an outdoor haven with a quirky, fun personality. In his leisure time, Dr. Frias enjoys skiing, cycling, rooting for the Portland Timbers soccer team and spending time with his amazing family and friends.

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  • M.D., Mayo Medical School, Rochester Minnesota 1998
  • Residency:

    • Obstetrics and gynecology, University of Utah, Salt Lake City, 2002
  • Fellowship:

    • Maternal-fetal medicine, obstetrics and gynecology, University of Utah, Salt Lake City, 2005
  • Certifications:

    • American Board of Obstetrics and Gynecology, 2005

Memberships and associations

  • Society of Maternal Fetal Medicine


  • "Zika virus infection in pregnant rhesus macaques causes placental dysfunction and immunopathology." Nature Communications  In: , Vol. 9, No. 1, 263, 01.12.2018.
  • "Effects of maternal western-style diet on amniotic fluid volume and amnion VEGF profiles in a nonhuman primate model." Physiological Reports  In: , Vol. 6, No. 20, e13894, 01.10.2018.
  • "Response." Radiology  In: , Vol. 288, No. 2, 01.08.2018, p. 634-635.
  • "Maternal high-fat diet reversal improves placental hemodynamics in a nonhuman primate model of diet-induced obesity." International Journal of Obesity  In: , 13.07.2018, p. 1-11.
  • "High-fat diet effects on amniotic fluid volume and amnion aquaporin expression in non-human primates." Physiological Reports  In: , Vol. 6, No. 14, e13792, 01.07.2018.
  • "Novel Detection of Placental Insufficiency by Magnetic Resonance Imaging in the Nonhuman Primate." Reproductive Sciences  In: , Vol. 25, No. 1, 01.01.2018, p. 64-73.
  • "Adverse Placental Perfusion and Pregnancy Outcomes in a New Nonhuman Primate Model of Gestational Protein Restriction." Reproductive Sciences  In: , Vol. 25, No. 1, 01.01.2018, p. 110-119.
  • "Gadolinium chelate safety in pregnancy : Barely detectable gadolinium levels in the juvenile nonhuman primate after in utero exposure." Radiology  In: , Vol. 286, No. 1, 01.01.2018, p. 122-128.
  • "A cautionary response to SMFM statement : pharmacological treatment of gestational diabetes." American Journal of Obstetrics and Gynecology  In: , 01.01.2018.
  • "First trimester alcohol exposure alters placental perfusion and fetal oxygen availability affecting fetal growth and development in a non-human primate model." American Journal of Obstetrics and Gynecology  In: , Vol. 216, No. 3, 01.03.2017, p. 302.e1-302.e8.
  • "Folding, but not surface area expansion, is associated with cellular morphological maturation in the fetal cerebral cortex." Journal of Neuroscience  In: , Vol. 37, No. 8, 22.02.2017, p. 1971-1983.
  • "IFPA meeting 2016 workshop report II : Placental imaging, placenta and development of other organs, sexual dimorphism in placental function and trophoblast cell lines." Placenta  In: , 10.01.2017.
  • "Early first trimester uteroplacental flow and the progressive disintegration of spiral artery plugs : New insights from contrast-enhanced ultrasound and tissue histopathology." Human Reproduction  In: , Vol. 32, No. 12, 01.01.2017, p. 2382-2393.
  • "Genomic Variants Associated with Resistance to High Fat Diet Induced Obesity in a Primate Model." Scientific Reports  In: , Vol. 6, 36123, 04.11.2016.
  • "Functional imaging of the nonhuman primate Placenta with endogenous blood oxygen level–dependent contrast." Magnetic Resonance in Medicine  In: , Vol. 76, No. 5, 01.11.2016, p. 1551-1562.
  • "When is the optimal time to deliver late preterm IUGR fetuses with abnormal umbilical artery Dopplers?" Journal of Maternal-Fetal and Neonatal Medicine  In: , Vol. 29, No. 5, 03.03.2016, p. 690-695.
  • "Quantitative assessment of placental perfusion by contrast-enhanced ultrasound in macaques and human subjects." American Journal of Obstetrics and Gynecology  In: , Vol. 214, No. 3, 01.03.2016.
  • "Influence of high fat diet and resveratrol supplementation on placental fatty acid uptake in the Japanese macaque." Placenta  In: , Vol. 36, No. 8, 01.08.2015, p. 903-910.
  • "Gadolinium chelate contrast material in pregnancy : Fetal biodistribution in the nonhuman primate." Radiology  In: , Vol. 276, No. 1, 01.07.2015, p. 110-118.
  • "Using dynamic contrast-enhanced MRI to quantitatively characterize maternal vascular organization in the primate placenta." Magnetic Resonance in Medicine  In: , Vol. 73, No. 4, 01.04.2015, p. 1570-1578.
  • "Vitamin C supplementation ameliorates the adverse effects of nicotine on placental hemodynamics and histology in nonhuman primates." American Journal of Obstetrics and Gynecology  In: , Vol. 212, No. 3, 01.03.2015.
  • "Impact of maternal obesity on fetal programming of cardiovascular disease." Physiology  In: , Vol. 30, No. 3, 2015, p. 224-231.
  • "What is the optimal gestational age for women with gestational diabetes type A1 to deliver?" American Journal of Obstetrics and Gynecology  In: , Vol. 211, No. 4, 01.10.2014, p. 418.e1-418.e6.
  • "High-fat maternal diet during pregnancy persistently alters the offspring microbiome in a primate model." Nature Communications  In: , Vol. 5, 3889, 20.05.2014.
  • "The Placenta in Obesity and Diabetes MelLitus."   Pathobiology of Human Disease: A Dynamic Encyclopedia of Disease Mechanisms. Elsevier Inc., 2014. p. 2395-2402.
  • "Beneficial and cautionary outcomes of resveratrol supplementation in pregnant nonhuman primates." FASEB Journal  In: , Vol. 28, No. 6, 2014, p. 2466-2477.
  • "Fetal pulmonary arterial vascular impedance reflects changes in fetal oxygenation at near-term gestation in a nonhuman primate model." Reproductive Sciences  In: , Vol. 20, No. 1, 01.2013, p. 33-38.
  • "The effect of race/ethnicity on adverse perinatal outcomes among patients with gestational diabetes mellitus." American Journal of Obstetrics and Gynecology  In: , Vol. 207, No. 4, 10.2012.
  • "Restriction of placental vasculature in a non-human primate : A unique model to study placental plasticity." Placenta  In: , Vol. 33, No. 1, 01.2012, p. 73-76.
  • "Obesity : A transgenerational problem linked to nutrition during pregnancy." Seminars in Reproductive Medicine  In: , Vol. 30, No. 6, 2012, p. 472-478.

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