Outcome of IVF pregnancies following severe OHSS.

Because severe ovarian hyperstimulation syndrome (OHSS) is a potentially life-threatening iatrogenic complication, much effort is made to prevent it and the anticipated pregnancy naturally becomes of secondary importance. There are many publications on OHSS, but very few on pregnancy outcomes. This work is to review the effect of OHSS on pregnancy outcome along the pregnancy course. Hospitalized patients with severe OHSS are exposed to several insults that could affect pregnancy outcome in its early stages: the ovarian hyperstimulation for IVF itself, haemodynamic instability that involve haemoconcentration, hypoxia, liver and renal dysfunction, and exposure to high endogenous oestrogens, cytokines, renin, angiotensin and prostaglandins. There is a paucity of data on the relation of OHSS and pregnancy complications. The incidence of multiple pregnancies, gestational diabetes mellitus, placental abruption prematurity and low birthweight is higher in cases of pregnancy complicated by severe OHSS. Therefore, these pregnancies should be considered as high-risk pregnancies, and followed/treated as such. As prevention is the best 'treatment' for OHSS, this may imply the need for more patient-friendly or mild stimulation protocols.