Prorenin periconceptionally and in pregnancy: Does it have a physiological role?

Pregnancy demands major cardiovascular, renal and endocrine changes to provide an adequate blood supply for the growing fetus. The renin-angiotensin-aldosterone system plays a key role in this adaptation process. One of its components, prorenin, is released in significant amounts from the ovary and uteroplacental unit. This review describes the sources of prorenin in the periconception period and in pregnancy, including its modulation by in-vitro fertilization protocols, and discusses its potential effects, among others focusing on preeclampsia. It ends with discussing the long-term consequences, even in later life, of inappropriate renin-angiotensin-aldosterone system activity in pregnancy and offers directions for future research. Ultimately, a full understanding of the role of prorenin periconceptionally and during pregnancy will help to develop tools to diagnose and/or prevent reproductive complications

Determinants of Maternal Renin-Angiotensin-Aldosterone-System Activation in Early Pregnancy: Insights From 2 Cohorts

Context: The corpus luteum (CL) secretes prorenin, renin’s inactive precursor. It may thus contribute to the renin-angiotensin-aldosterone-system (RAAS) activation that is required for maternal adaptation in pregnancy. Whether this activation is disturbed in pregnancies lacking a CL is unknown. Objective: The objective of this work is to investigate maternal RAAS determinants in early pregnancy. Design and Setting: Two observational prospective cohort studies took place at 2 tertiary referral hospitals. Patients and Intervention(s): Pregnancies (n = 277) were stratified by CL number and in vitro fertilization (IVF) protocol: 0 CL (programmed cycle frozen embryo transfer [FET], n = 28), 1 CL (natural cycle FET, n = 41 and spontaneous conceptions, n = 139), and more than 1 CL (ovarian stimulation and fresh embryo transfer, n = 69). Methods: Quantification was performed for maternal prorenin, renin, and aldosterone blood levels at 5, 9, and 11 weeks of gestation. Results: Prorenin and renin were lower in the absence of a CL at all time points when compared to 1 CL, whereas prorenin, renin, and aldosterone were higher in the presence of more than 1 CL vs 1 CL (P < .05). Ovarian stimulation with menopausal gonadotropin resulted in higher prorenin, renin, and aldosterone concentrations during the late first trimester than recombinant follicle-stimulating hormone (P < .05). Prorenin, and to a lesser degree renin, correlated positively with serum progesterone and relaxin, but not serum estradiol. Total follicle diameter, body mass index (BMI), polycystic ovary syndrome (PCOS), and antimüllerian hormone (AMH) were additional determinants of circulating prorenin. Finally, pregnancies conceived in the

Vitamin D prevents endothelial progenitor cell dysfunction induced by sera from women with preeclampsia or conditioned media from hypoxic placenta

Context: Placenta-derived circulating factors contribute to the maternal endothelial dysfunction underlying preeclampsia. Endothelial colony forming cells (ECFC), a sub-population of endothelial progenitor cells (EPCs), are thought to be involved in vasculogenesis and endothelial repair. Low vitamin D concentrations are associated with an increased risk for preeclampsia. Objective: We hypothesized that the function of human fetal ECFCs in culture would be suppressed by exposure to preeclampsia-related factors-preeclampsia serum or hypoxic placental conditioned medium- in a fashion reversed by vitamin D. Design, Setting, Patients: ECFCs were isolated from cord blood of uncomplicated pregnancies and expanded in culture. Uncomplicated pregnancy villous placenta in explant culture were exposed to either 2% (hypoxic), 8% (normoxic) or 21% (hyperoxic) O2 for 48 h, after which the conditioned media (CM) was collected. Outcome Measures: ECFC tubule formation (Matrigel assay) and migration were examined in the presence of either maternal serum from preeclampsia cases or uncomplicated pregnancy controls, or pooled CM, in the presence or absence of 1,25(OH)2 vitamin D3. Results: 1,25(OH)2 vitamin D3 reversed the adverse effects of preeclampsia serum or CM from hypoxic placenta on ECFCs capillary-tube formation and migration. Silencing of VDR expression by VDR siRNA, VDR blockade, or VEGF pathway blockade reduced ECFC functional abilities. Effects of VDR or VEGF blockade were partially prevented by vitamin D. Conclusion: Vitamin D promotes the capillary-like tubule formation and migration of ECFCs in culture, minimizing the negative effects of exposure to preeclampsia-related factors. Further evaluation of the role of vitamin D in ECFC regulation and preeclampsia is warranted. © 2014 Brodowski et al

Pregnancies in liver and kidney transplant recipients : a review of the current literature and recommendation

In this article, we focus on the biggest groups of organ transplant recipients, patients with a kidney or liver graft. Among these patients, about one sixth included women of childbearing potential. Therefore, the wish of getting pregnant is frequent in these peculiar patients, and careful planning and management of the pregnancies requires the expertise of obstetricians, midwives and transplant experts. Altogether, the outcome of the pregnancies in these women is acceptable. About 75% off all pregnancies ended successfully with live births, and this is comparable if not superior to pregnancies in healthy women. This success might be caused not only by the special and intensive care provided to these high-risk pregnancies by the transplant centres but also by the low rate of unplanned pregnancies. The risk of rejections and organ loss after delivery is about 10%, and it is slightly enhanced in liver transplant recipients (LTRs) in comparison to kidney graft recipients (KTRs) but the number of organ losses in direct association with a pregnancy is rare. However, there is not only a higher frequency of pregnancy-associated disorders such as pre-eclampsia and preterm delivery but also an acceleration of hypertension, new-onset diabetes mellitus and newly arising infections also favoured by the maintained immunosuppressive therapy. This implies a specialized 'control system' for these pregnant women that comprises ultrasound and Doppler investigation for risk assessment, infection screening, suitable therapy and the choice of non-teratogenic immunosuppressives. Antihypertensive treatment must be well balanced and adjusted to the possible growth-retarding effect on the foetus as well as on the co-morbidity of the mother. Finally, supplementation of vitamin D and iron is much more important in these transplanted women than in healthy pregnant women as vitamin D deficiency and anaemia are discussed to have an impact on pre-eclampsia and preterm delivery. These claims are widely discussed. Furthermore, the current literature is systematically reviewed by Scopus analysis