PhD defence I.F. (Igna) Reijnders

The placenta connects the blood flow of mother and fetus. Non-optimal placental development and functioning can lead to placenta-related pregnancy complications. During the periconception period, maternal conditions such as age, parity, but also diet and lifestyle can influence placental development. There is no optimal method to assess placental development this early. Using three-dimensional ultrasound, the placenta itself and the blood flow to and within the placenta can be imaged. By storing images, placental size and amount of blood vessels can be shown and measured in a lifelike manner using Virtual Reality (VR). This allows for early and non-invasive investigation of the associations between placental development and maternal nutrition and lifestyle, embryonic/fetal growth and birth outcomes. First, this thesis describes existing evidence for an adverse influence of smoking during the periconception period on placental development and function. Furthermore, it was shown that vascular volume measurements of uterus, embryo and placenta using 3D PD ultrasound and VR are feasible and reliable. These measurements were then repeated in the first trimester in 214 pregnant women. First-trimester placental development was associated with embryonic/fetal growth and birth outcome, with different outcomes for boys and girls. Furthermore, the impact of impaired hemodynamic adjustment in the first trimester on placental development appears to be greater in pregnancies with placenta-related complications. Finally, larger and/or placentas with more vessels in early pregnancy were found to adapt better to pressure increase in an experimental perfusion model after birth. This could lead to better birth outcomes.

The PhD defences will not take place publicly in the usual way. A live stream link has been provided to candidate. The ceremony will begin exactly at 15:30.