P-778 Exploration of maternal proteome over pregnancy based on corpus luteum number at conception

Abstract

Abstract Study question Does the maternal plasma proteome profile differ depending on corpus luteum (CL) number at conception? Summary answer The proteome profiles show differences depending on the number of CL at conception and some differentially regulated proteins may be linked to preeclampsia. What is known already Frozen embryo transfer (FET) in a programmed cycle is associated with a higher risk for preeclampsia. These women also experience impaired maternal vascular health in early pregnancy and differences in the endocrine environment, such as a lack of relaxin. These changes may be related to the absence of products from the CL. Study design, size, duration Prospective cohort study (N = 878) between June 2015 and December 2018 in an academic setting. Participants/materials, setting, methods Women with viable pregnancies were recruited at 6-8 weeks and compared by number of CL: no CL (programmed cycle FET), 1 CL (spontaneous pregnancy after infertility, modified natural cycle FET), and multiple CL (fresh IVF). Peripheral blood was collected, and plasma frozen at -80 °C. MS-based proteomics was used to determine proteome profiles of 4 participants in each group at 11-14 and 35-37 weeks’ gestation and 6-12 weeks postpartum. Main results and the role of chance Over 1000 protein groups were identified and 650 could be quantified in all samples. We found significant differences based on number of CL. Many of these proteins have been reportedly linked to preeclampsia. The results in the first trimester indicate the importance of aminopeptidases involved in the breakdown of angiotensin III. In addition, extracellular matrix proteins were found to be differentially regulated. Also, at the end of the third trimester certain proteins were differentially regulated among the groups. Limitations, reasons for caution This was a pilot study and unable to determine if differences are related to selection bias or could exist already pre-pregnancy independent of CL number at conception. Wider implications of the findings The findings warrant confirmation in a larger patient cohort. The detected differences in the proteome might shed light upon phenomena observed in women during pregnancy that lack a CL and as well as molecular mechanisms underlying preeclampsia. Trial registration number not applicable