PROJECT SUMMARY/ABSTRACT The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Maternal- Fetal Medicine Units (MFMU) Network was created in 1986 to conduct clinical research studies in obstetrics and perinatal medicine. The MFMU Network, consisting of a number of major academic clinical centers, a data coordinating center (DCC), and the NICHD, will serve as the first-line infrastructure for implementing multi-site obstetric clinical trials and observational studies. Research studies conducted within the MFMU Network will be aimed at reducing maternal morbidity and mortality related to pregnancy, reducing fetal and infant morbidity and mortality related to preterm birth and fetal growth abnormalities, and expanding the evidence on therapeutic products used during pregnancy and lactation. To fulfill this mission, the MFMU Network plans to conduct 5-10 new studies. The MFMU Network structure allows studies to be completed in a more rigorous and reproducible fashion and more efficiently than individual multi-center projects. The overall purpose of the DCC is to make sure that the studies are designed to minimize bias, are conducted using rigorous protocols and procedures, and the results analyzed and interpreted appropriately to ensure the validity of the conclusions. The aims of the DCC are to provide scientific and biostatistical expertise through collaborations with Network and non-Network investigators on study design, conduct, analysis and reporting of clinical studies. The DCC will conduct safety and interim analyses for the Data and Safety Monitoring Board, collaborate with investigators on statistical analyses and the dissemination of study results, and share datasets and resources. The DCC will provide a flexible data management system and collaborate with investigators on the conduct and monitoring of each study including creation of study documents, training, and reporting to the Steering Committee, NIH, other committees and/or working groups, as well as the Food and Drug Administration for any studies under an IND/IDE. Lastly, the DCC will coordinate communication through both private and public websites, and provide the logistical and administrative support to the overall Network organization necessary to run efficient and productive studies. Through effective organization, communication, and logistical, technical and scientific support, the DCC will continue to provide the framework for the MFMU Network to address the key scientific questions in obstetrics, obstetric pharmacology, and lactation clinical practice.