Nikolaos Zacharias, MD, Obstetrics & Gynecology, Houston, TX, Memorial Hermann - Texas Medical Center


Obstetrics & GynecologyHouston, TX

Birth Defect & Fetal Treatment, General Obstetrics, Maternal & Fetal Medicine/High Risk

Director of Maternal-Fetal Medical Education - Obstetrix Medical Group of Houston; Maternal-Fetal Medicine Consultant - Saint Joseph Medical Center; Clinical Associate Professor of Obstetrics - University of Houston College of Medicine

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  • Nikolaos Zacharias, MD, FACOG, is a native of Greece; he earned his medical diploma with excellence from the National & Kapodistrian University of Athens, Greece (1995) reciting the Hippocratic Oath as a top graduate in his class. Dr. Zacharias received numerous scholarships for undergraduate and postgraduate education (1989-2002). He trained in Obstetrics & Gynecology at Baylor College of Medicine, (1998-2002), elected chief resident in 2001. He received the CREOG Academic Achievement Award four consecutive years (1999-2002) for scoring at the top 3% of his U.S. peers.

    His passion for prenatal sonography and profound interest in pregnancy complications led him to a fellowship in Maternal-Fetal Medicine at the University of Texas Medical Branch, in Galveston, Texas (2002-2005), where he received the UTMB Hospital Academic Fellowship Award. Dr. Zacharias returned to Baylor as assistant professor of OB/GYN, in the Maternal Fetal Medicine Division (2005-2013). He served as medical director of the Harris Health System (HHS) Prenatal Ultrasound Screening Program (2005-2012) and as founding medical director of the Ben Taub Maternal Fetal Medicine Prenatal Ultrasound Unit (2008-2012). Dr. Zacharias was a founding member of the Texas Children’s Fetal Center 2006-2013, an attending physician and teaching faculty at Ben Taub General (2005-2013) and Texas Children’s Hospital (2008-2013). He is board-certified in OB/GYN (2008) and Maternal Fetal Medicine (2011). Dr. Zacharias received Baylor's student faculty teaching award (2011) and was elected to America's Top Obstetricians & Gynecologists (2012). He is a fellow of ACOG (2010) and regular member of SMFM (2012). He served as the medical director of the AIUM-accredited antenatal testing center and assistant professor of OB/GYN-MFM at LBJ Hospital and McGovern Medical School at UTHEALTH (2014-2019), supervising >60,000 prenatal ultrasounds and receiving annual Dean's teaching awards. He has now joined MEDNAX/Obstetrix Group.

Education & Training

  • U Texas Med BranchFellowship
  • Baylor College of Medicine
    Baylor College of MedicineChiefResidency
  • Baylor College of Medicine
    Baylor College of MedicineResidency
  • Baylor College of Medicine
    Baylor College of MedicineInternship
  • University of Athens
    University of AthensMedicalSchool
  • Sorbonne UniversityOtherTraining
  • University of CambridgeOtherTraining
  • University of Texas Medical Branch Graduate School of Biomedical SciencesOtherTraining

Certifications & Licensure

  • TX State Medical License
    TX State Medical License 2005 - 2021
  • American Board of Obstetrics and Gynecology Obstetrics & Gynecology
  • American Board of Obstetrics and Gynecology Maternal-Fetal Medicine

Awards, Honors, & Recognition

  • Dean’s Faculty Teaching Award McGovern Medical School at UTHEALTH, 2015-2017
  • Regular Member Society for Maternal-Fetal Medicine, 2012
  • Elected to America’s Top Obstetricians & Gynecologists Consumers' Research Council of America, 2012
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Publications & Presentations


Journal Articles

  • First Neonatal Demise with Travel-Associated Zika Virus Infection in the United States of America.  
    Zacharias N, Whitty J, Noblin S, Tsakiri S, Garcia J, Covinsky M, Bhattacharjee M, Saulino D, Tatevian N, Blackwell S., American Journal of Perinatology Reports, 4/13/2017
  • Maternal morbidity in patients with morbidly adherent placenta treated with and without a standardized multidisciplinary approach.  
    Shamshirsaz AA, Fox KA, Salmanian B, Diaz-Arrastia CR, Lee W, Baker BW, Ballas J, Chen Q, Van Veen TR, Javadian P, Sangi-Haghpeykar H, Zacharias N, Welty S, Cassady CI..., American Journal of Obstetrics and Gynecology, 2/1/2015
  • Prospective trial on obstructive sleep apnea in pregnancy and fetal heart rate monitoring  
    Olivarez S, Maheshwari B, McCarthy M, Zacharias NM, Van den Veyver I, Casturi L, Sangi-Haghpeykar H, Aagaard-Tillery K, American Journal of Obstetrics and Gynecology, 8/1/2010
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Books/Book Chapters


  • Maternal-fetal and gestational characteristics and microsomal aromatase activity in human placentas
    Zacharias NM, Society of Maternal-Fetal Medicine Annual (The pregnancy TM) Meeting, Dallas, TX, 2/1/2012
  • Prevalence and clinical significance of Polyhydramnios during Screening Prenatal Sonography in a modern Hispanic cohort
    Kim J, Sangi-Haghpeykar H, Zacharias NM, Society of Maternal-Fetal Medicine Annual (The pregnancy TM) Meeting, San Francisco, CA, 2/1/2011
  • Creating a customized Birth Weight Standard for Harris County’s Hispanic Population
    Amini S, Francis A, Sangi-Haghpeykar H, Gardosi J, Zacharias NM, Society of Maternal-Fetal Medicine Annual (The pregnancy TM) Meeting, San Francisco, CA, 2/1/2011
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  • Fetal anomaly case presentations 
    Texas Medical Center, Houston, TX - 3/1/2013
  • Prenatal imaging of fetal syndromes 
    Baylor College of Medicine, Houston TX - 2/1/2013
  • Fetal growth restriction 
    Baylor College of Medicine, Houston TX - 8/1/2012
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  • Member, Quality Assurance Committee - Ben Taub General Hospital 2011 - 2013
  • Member, Radiation Safety Committee - Baylor College of Medicine 2008 - 2013
  • Member, Texas Children's Fetal Center 2006 - 2013

Professional Memberships

Other Languages

  • Spanish, French, Greek

Hospital Affiliations