The IMMUN-OR study aims to study HLA-C/KIR combinations when looking at the risk of development of preeclampsia (PE) in pregnancies after oocyte donation. With the use of oocyte donation currently on the rise, the importance of identifying risk factors for the higher frequency of PE development is clear. Certain HLA-C/KIR combinations have already been linked to higher risk of obstetric complications. This study will look at these combinations within the specific situation of oocyte donation. This will further investigate the importance of the immunological interface when looking at PE. Participants will be chosen from a database of all the live births after oocyte donation at our center. The research team will contact the mother, child and donor. If all three agree to participate, they will be invited to our center, where the research team will take a cheek swab. This swab will then be used to isolate a DNA sample. With these samples, we can determine the HLA-C/KIR combination for each threesome. When all samples have been collected, two groups are made based off their health outcome: one group that did develop PE during their pregnancy, and one group that did not develop PE. The different HLA-C/KIR combinations will be compared, and the research team will look to discover if one combination is linked to a higher occurrence of PE development.