von Versen-Höynck F, et al. - In this investigation, researchers ascertained if in vitro fertilization pregnancies without a corpus luteum (CL) disrupt maternal circulatory adaptations and increase preeclampsia risk. Before, during, and after pregnancy, women with 0 (n=26), 1 (n=23), or >1 (n=22) CL were serially evaluated. Since increasing arterial compliance is a major physiological adaptation during pregnancy, they evaluated the velocity and transit time of the carotid-femoral pulse wave. The most striking changes in the velocity of the carotid-femoral pulse wave and carotid-femoral transit from pregnancy in the 0-CL cohort were 10 to 12 weeks of gestation. Compared with modified natural frozen embryo transfer cycles (1 CL), programmed frozen embryo transfer cycles (0 CL) were related to higher rates of preeclampsia and preeclampsia with severe features. An absence of the CL perturbed the maternal circulation in early pregnancy and increased the incidence of preeclampsia in common in vitro fertilization protocols.