Assisted reproduction is associated with an increased risk for hypertensive disease in pregnancy. The underlying pathophysiology is still debated. Endothelial dysfunction is a central component of ...hypertensive disease and can be determined non-invasively by Pulse-Amplitude-Tonometry (PAT).
We hypothesized that a non-physiologic maternal environment in early pregnancy, specifically the absence of a corpus luteum (CL), negatively impacts maternal endothelial health.
For this ongoing study women with spontaneous conceptions and conceptions after assisted reproduction were recruited at an academic infertility clinic after confirmation of a viable intrauterine pregnancy between 7 and 10weeks gestation. Exclusion criteria were multiples, chronic hypertension, chronic kidney disease, diabetes mellitus, autoimmune disease, age >50years or BMI >30. Endothelial function was determined using the Endo-PAT2000 system by calculating the reactive hyperemia index (RHI) at 11–14weeks gestation. RHI ⩽1.67 is associated with a higher cardiovascular risk. A fasting lipid panel was obtained for each participant. Statistical analysis was performed using Kruskal–Wallis-test with post hoc analysis. Results are shown as means and standard errors.
47 women participated in the research visit. We found a significant difference in endothelial function with lower RHI in pregnant women with no CL (N=10, RHI=1.65±0.08; p=0.04) compared to women with 1 CL (N=21; RHI=1.99±0.11). This difference was also evident between frozen-thawed ET in programmed (N=10; RHI=1.65±0.03, p=0.03) compared to natural cycles (N=9; RHI=1.95±0.08). There was no difference when comparing the data to the group of women with fresh ET and supraphysiologic numbers of CL. Age, blood pressure and lipid levels were not different between groups.
A non-physiologic maternal environment, which is generated by suppression of CL in programmed cycles, negatively impacts maternal endothelial health in early pregnancy. The cause could be the absence of CL products. Specifically, relaxin, a potent vasodilator, might play a crucial role. A deficiency in relaxin could therefore contribute to an increased risk of hypertensive disease in pregnancy after assisted reproduction.
