The Maternal-Fetal Medicine Division at the University of Texas Medical School at Houston (UT-Houston) is reapplying for its third cycle of participation in the NICHD MFMU Network (initially funded 6/2001). Dr. Susan Ramin, the original PI, became OB/GYN Chair in 10/2006 and Dr. Sean Blackwell was recruited to UT-Houston to serve as PI starting in 6/2007. Dr. Blackwell brings experience within the MFMU Network (prior WSU Alternate-PI 2003-2006), innovation, and unique expertise as the PI. Importantly, he has successfully demonstrated his leadership skills during the transition by improving data quality and increasing subject recruitment/retention. The MFMU Network at UT-Houston conducts the majority of its operations at its two university-affiliated teaching hospitals: Memorial Hermann Hospital (4,800 annual deliveries) and Lyndon B. Johnson General Hospital (3,800 annual deliveries). The administrative and physician leadership at both locations have provided unobstructed access to potential subjects, high-quality research space, and a culture of research. Collaborations with private OB/GYN physicians and UT faculty have been strengthened and resulted in _ improved access for out-patient studies. The UT-Houston MFM research infrastructure also supports other on-going NICHD multi-center studies including Pathogenesis of Preeclampsia Network, GPN Network, and the National Children's Study. This application describes the track record of recruitment and retention (including long-term follow-up), the expertise and productivity of our MFM faculty, and the scientific contributions of UT-Houston to the MFMU Network. We describe a concept study that addresses a significant health problem (gestational diabetes and fetal overgrowth), which is innovative and demonstrates our understanding of the necessary considerations and approach needed in conducting large, multi-center, clinical trials. UT-Houston has the available patient population, institutional resources, and dedication of a highly- qualified PI to contribute to the mission of the MFMU for the next cycle and beyond.