CRS Hosts Special Seminars
CRS hosted two special seminars in May. Dr. Larry Chamley, PhD, from the University of Auckland, gave a compelling presentation titled “Placental extracellular vesicles, a cause and treatment of the long-term cardiovascular consequences of preeclampsia?” Dr. Michael Davies, MPH, PhD, from the University of Adelaide, delivered an interesting talk titled “Fertility in the fast lane - 21st century technologies and reproductive outcomes.”
Dr. Chamley, PhD on “Placental extracellular vesicles, a cause and treatment of the long-term cardiovascular consequences of preeclampsia?”
The ability for the pregnant person’s cardiovascular system to accommodate the changes required for a healthy pregnancy, including increased heart rate, increased blood volume, and increased stroke volume without a dangerous change in blood pressure, is a remarkable feat. Dr. Chamley’s research supports that EVs shed by the placenta impact the plasticity of the pregnant person’s cardiovascular system.
To maintain a proper, healthy pregnancy, the placenta is involved in maternal-fetal communication. One means of this communication is via extracellular vesicles (EVs). EVs are like little packages one cell wraps up and ships out, which then travel through the blood stream and are eventually taken up by other cells. The role and impact of placental EVs remains elusive. However, Dr. Chamley’s research suggests that placental EVs may have lasting effects on cardiovascular health beyond pregnancy. For example, when EVs extracted from human placenta were injected into mice, the researchers observed long lasting effects on the ability of the mouse arteries to constrict when exposed to various vasoconstrictors. This is a significant finding because the pregnant person’s cardiovascular system must adjust significantly during pregnancy to properly support the growing fetus. If the pregnant person’s cardiovascular system cannot adjust properly, pregnancy complications can arise.
Dr. Chamley’s lab is particularly interested in the pregnancy complication preeclampsia, in which the pregnant person suffers from hypertension that can be lethal for both the pregnant person and the fetus. When EVs extracted from preeclamptic human placentas were injected into rats, the researchers observed increased hypertension and increased arterial constriction. While further research is needed, current findings suggest that placental EVs influence the cardiovascular system, with their effects shaped by placental health. Notably, when placental EVs from healthy human placentas were injected into a hypertensive rat model, the researchers observed a rescue effect, specifically there was a decrease in blood pressure. Overall, these findings have broad implications for those suffering from preeclampsia and Dr. Chamley’s group hopes to one day identify how the placental EVs inflict these changes so they can develop a therapy to treat preeclampsia.
Dr. Davies, MPH, PhD on “Fertility in the fast lane - 21st century technologies and reproductive outcomes”
Dr. Davies has been a professor at the University of Adelaide for the past 26 years. His talk started with an overview of the history of IVF. IVF practices have changed dramatically since its inception over 50 years ago. Early on, the success rate of IVF was relatively low. To overcome this hurdle, transferring two or more embryos at a time was a common practice. Although this increased the success rate, it also resulted in higher rates of preterm birth, increased health complication rates of the babies born, and drastically increased the costs associated with a baby's first year of life. As these issues came to light and the efficiency of IVF increased, it became common practice only to transfer one embryo at a time.
Dr. Davies then focused on the history and use of clomiphene citrate, a selective estrogen receptor modulator (SERM). Clomiphene citrate was researched initially after World War 2 as a potential way to treat hormone-sensitive tumors and as a short-term contraceptive. Currently, clomiphene citrate is used to treat people suffering from anovulation. To get pregnant naturally, a person must first ovulate, or release an egg, which can then be fertilized by sperm. Although clomiphene citrate has been used worldwide since the 1960s, Dr. Davies' research suggests there are alternatives, such as Letrozole, which has a shorter half-life and therefore fewer off-target effects. Overall, Dr. Davies provided a provocative discussion on the history and current practices in the field of fertility and in vitro fertilization (IVF), discussions which will surely continue as IVF technologies evolve, drugs are tested and developed, and treatment protocols are tested and refined.