Prevention of Preeclampsia With Aspirin in Recipients of Donated Oocytes.

Various markers have been proposed for the early diagnosis of preeclampsia: determination of mean arterial pressure; presence of multiple risk factors of preeclampsia; biochemical, ultrasound, and angiogenic markers; uterine artery Doppler, etc. These are used to determinate which patients have an increased risk of developing preeclampsia during gestation, and therefore carry out closer monitoring of pregnancy in this population. In addition, these markers can also identify patients at increased risk of developing other problems such as IUGR or preterm labor. For nearly 30 years, there have been multiple studies trying to demonstrate that aspirin prevents the onset of preeclampsia with inconclusive results. However, recent studies in which aspirin was administered at an early stage (before 16 weeks of gestation) in patients at high risk of complications, have demonstrated a decrease in the incidence of this entity. Thus, administration of aspirin to patients at high risk (patients classified with a high risk of complications during pregnancy, based on markers mentioned above) seems to be useful in preventing onset of preeclampsia, IUGR and other complications, whenever it is administered at an early stage, as shown by several studies carried out so far. The incidence of preeclampsia, IUGR and other complications of pregnancy is increased in patients undergoing treatment for ovulation induction, being much higher in recipients of donated oocytes. It appears that this increase may be explained by immunological processes. The focus lies on the interaction between HLA-C fetal antigen with the maternal natural killer cells. We postulate, therefore, that the administration of aspirin in recipients of donated oocytes at an early stage of pregnancy, may also reduce the incidence of preeclampsia in this group of patients. Moreover, it has been observed that patients with preeclampsia exhibit lower levels of VEGF, PlGF and PAPP-A (factors involved in placental angiogenesis) and that this is accompanied by an increase in the sFlt1 (a potent PIGF and VEGF antagonist).