In vivo31P-MR spectroscopy in normal pregnancy, early and late preeclampsia: A study of placental metabolism

IntroductionPreeclampsia affects about 3% of pregnancies and the placenta is believed to play a major role in its pathophysiology. Lately, the role of the placenta has been hypothesised to be more pronounced in preeclampsia of early (<34 weeks) rather than late (≥34 weeks) onset. 31P Magnetic Resonance Spectroscopy (MRS) enables non-invasive, in vivo studies of placental metabolism. Our aim was to study placental energy and membrane metabolism in women with normal pregnancies and those with early and late onset preeclampsia.MethodsThe study population included fourteen women with preeclampsia (five with early onset and nine with late onset preeclampsia) and sixteen women with normal pregnancy (seven with early and nine with late pregnancy). All women underwent a 31P-MRS examination of the placenta.ResultsThe phosphodiester (PDE) spectral intensity fraction of the total 31P signal and the phosphodiester/phosphomonoester (PDE/PME) spectral intensity ratio was higher in early onset preeclampsia than in early normal pregnancy (p = 0.03 and p = 0.02). In normal pregnancy the PDE spectral intensity fraction and the PDE/PME spectral intensity ratio increased with increasing gestational age (p = 0.006 and p = 0.001).DiscussionSince PDE and PME are related to cell membrane degradation and formation, respectively, our findings indicate increased cell degradation and maybe also decreased cell proliferation in early onset preeclampsia compared to early normal pregnancy, and with increasing gestational age in normal pregnancy.ConclusionsOur findings could be explained by increased apoptosis due to ischaemia in early onset preeclampsia and also increased apoptosis with increasing gestational age in normal pregnancy.