CLICK ON weeks 0 - 40 and follow along every 2 weeks of fetal development
New clues linking pre-eclampsia and cholesterol
A study, led by researchers at the University of Nottingham, United Kingdom (UK), suggests that the body's normal defence mechanism of flushing out damaging cholesterol from blood may be disrupted by pre-eclampsia.
The results of the study, published in the June edition of the Journal of Lipid Research, show that although the mother's body attempts to compensate and offset the effect of higher cholesterol levels, her damage limitation fails as the placenta has already been compromised by the disease.
This has prompted researchers to undertake a more in depth study monitoring mothers with pre-eclampsia after delivery to investigate whether their ability to effectively remove excess cholesterol from their cells in the weeks following birth continues to be disrupted.
If so, it could pave the way for tests to identify women most at risk of developing heart disease and who may benefit from receiving preventative advice and medication.
"This is a very interesting finding and illustrates the importance of having the correct balance of cholesterol during pregnancy. The ability of mothers to effectively remove excess cholesterol is essential — and monitoring cholesterol after delivery in women who suffered from pre-eclampsia could prove to be a useful indicator to identify those at high risk for early heart disease."
Pre-eclampsia is one of the leading causes of serious illness and death in pregnant women worldwide, affecting between two and eight per cent of pregnancies.
It is characterized by the onset of high blood pressure beginning after 20 weeks of pregnancy, or when a significant amount of protein is found in a woman's urine. It is routinely screened for in prenatal visits.
In severe cases, red blood cell breakdown is revealed as a low blood platelet count which can lead to impaired liver and kidney function, with swelling and shortness of breath from fluid accumulation in the lungs. Left untreated, this can lead to seizures. Severe pre-eclampsia increases risk of death to both mother and baby.
While many cases are mild, babies can be born smaller and prematurely.
Both women who develop pre-eclampsia and their babies are at increased risk of high blood pressure and heart disease. Mothers affected are eight times more likely to develop heart disease, their babies five times more.
During pregnancy, it is important for the fetus to receive some cholesterol from its mother to aid its growth and development and build basic fat reserves.
However, excessive amounts can be damaging and the body works to strip away surplus cholesterol by carrying it away in the blood to the liver to be processed and recycled.
The placenta also plays a role - as well as providing the baby with oxygen and essential nutrients, it helps regulate cholesterol passed to the unborn child.
However, the study found in pre-eclampsia, both the mother's system for removing cholesterol and the placental fail safe system are both compromised.
Preeclampsia is a pregnancy-specific condition that leads to increased cardiovascular risk in later life. A decrease in cholesterol efflux capacity is linked to CVD. We hypothesized that in preeclampsia there would be a disruption of maternal/fetal plasma to efflux cholesterol, as well as differences in the concentrations of both placental sterol 27-hydroxylase (CYP27A1) and apoA1 binding protein (AIBP). Total, HDL-, and ABCA1-mediated cholesterol effluxes were performed with maternal and fetal plasma from women with preeclampsia and normotensive controls (both n = 17). apoA1 and apoE were quantified by chemiluminescence, and 27-hydroxycholesterol (27-OHC) by GC-MS. Immunohistochemistry was used to determine placental expression/localization of CYP27A1, AIBP, apoA1, apoE, and SRB1. Maternal and fetal total and HDL-mediated cholesterol efflux capacities were increased in preeclampsia (by 10–20%), but ABCA1-mediated efflux was decreased (by 20–35%; P < 0.05). Maternal and fetal apoE concentrations were higher in preeclampsia. Fetal plasma 27-OHC levels were decreased in preeclamptic samples (P < 0.05). Placental protein expression of both CYP27A1 and AIBP were localized around fetal vessels and significantly increased in preeclampsia (P = 0.04). Placental 27-OHC concentrations were also raised in preeclampsia (P < 0.05). Increased HDL-mediated cholesterol efflux capacity and placental CYP27A1/27-OHC could be a rescue mechanism in preeclampsia, to remove cholesterol from cells to limit lipid peroxidation and increase placental angiogenesis.
The study, Increased Maternal and Fetal Cholesterol Efflux Capacity and Placental CYP27A1 Expression in Preeclampsia, was carried out in collaboration with academics at the University of Bern in Switzerland and King's College London.
Return to top of page
Monitoring pre-eclamptic mothers after delivery may help identify those
most at risk for developing heart disease.
Image Credit: public domain