RATIONALE: Syncytiotrophoblast microparticles (STBM) are shed into the maternal circulation in higher amounts in pre-eclampsia compared to normal pregnancy and are believed to be the stimulus for the systemic inflammatory response and endothelial cell damage which characterises the maternal syndrome. The excess shedding of STBM may be caused by hypoxia as a result of poor placentation, which is often a feature of pre-eclampsia. Similar placental pathology occurs in some cases of normotensive intrauterine growth restriction (nIUGR), but in the absence of maternal disease. OBJECTIVE: To examine whether the shedding of STBM in nIUGR occurs to the same extent as in pre-eclampsia. METHODS: A prospective case-control study in a tertiary referral centre of: 1) women with early-onset pre-eclampsia (EOPET or = 34 week), 3) women with nIUGR), 4) matched normal pregnant women (NPC), and 5) non-pregnant women. An ELISA using the antitrophoblast antibody NDOG2 was used to measure STBM levels in peripheral venous plasma. Non-parametric analyses were conducted with statistical significance set at p