Abstract: In the United States, there are nearly 4 million births per year and childbirth is the leading indication for hospitalization. Correspondingly, the prevention of adverse obstetric outcomes, including preterm birth and maternal morbidity, is an important goal, and clinical trials and observational studies designed to improve obstetric outcomes are of the utmost importance. The Maternal-Fetal Medicine Units (MFMU) Network, by creating a multi-institutional research infrastructure, is an important mechanism to accomplish this goal effectively. The Northwestern Study Center, through its use of innovative recruitment techniques and study design approaches, has been a productive member of the MFMU Network since 2001, and is composed of three institutions – Northwestern University, NorthShore University Health System, and Medical College of Wisconsin – that have a history of collaboration, including within the MFMU Network. In this proposal, we present the application of the Northwestern Study Center to renew its participation in the MFMU Network. Led by a team of experienced clinical researchers (William Grobman, MD, MBA; Emily Miller, MD, MPH; Beth Plunkett, MD, MPH; Anna Palatnik, MD; Gail Mallett, RN), the Northwestern Study Center will continue its significant contributions to the MFMU Network's goals though robust enrollment of socioeconomically diverse patients and the completion of novel and clinically-important studies.