Pre-eclampsia

Angie Benedetto

December 12, 2016

Introduction

About seventy percent of women with high blood pressure during pregnancy will develop pre-eclampsia, this condition can describe mild hypertension as well as severe hypertension with end-organ dysfunction including high levels of protein in the urine, eclampsia, hemolysis, higher liver enzymes, and low platelet count (HELLP) syndrome (Ghulmiyyah et al., 280). The true reason for this condition is unknown although there are some theories and identified symptoms that could help improve maternal and fetus mortality and morbidity, some theories of the cause of pre-eclampsia suggest “inadequate endovascular remodeling of uterine spiral arteries, immunologic intolerance between fetoplacental and maternal tissues, maladaptation to cardiovascular changes, excess inflammatory changes of pregnancy, abnormal angiogenesis, genetic abnormalities…”  (Ghulmiyyah et al., 281).

To understand this condition, we should understand that there are two stages to pre-eclampsia: early-onset pre-eclampsia and late-onset pre-eclampsia, this is imperative since research suggests that early-onset and late onset could be attributed to different factors. Early-onset pre-eclampsia, which occurs before 34 weeks of gestation, has been associated with poor placental implantation leading to chronic placental insufficiency with inflammatory factors guiding to hypertension. Late-onset pre-eclampsia, which develops at 34 weeks of gestation or after, has been classified as placental disease as well as the result of maternal metabolic and cardiovascular risk factors (K. Durst et al. 651 e1).

Even though the reason for this condition is not completely known, are there any ways to prevent this gestational disease? The purpose of this research paper is to investigate possibilities on pre-eclampsia prevention. It will discuss the relationship of pre-eclampsia with severe features of mothers’ BMI during pregnancy, dietary factors that could help prevent the disease, supplements, and physical exercise.

Discussion

Pre-eclampsia has been studied in many countries by various scientist, experiments correlating this disease and women’s body weight have been made at different times in history. Obesity affects approximately one third of reproductive-aged women, increasing rates of obesity may contribute to a higher incidence in hypertensive disorders among pregnant women (K. Durst et al). According to a study made in the Department of Obstetrics and Gynecology at Washington University of St. Luis where 10,196 women were involved it was determined that late-onset pre-eclampsia with severe features does have a correlation with Body Mass Index (BMI).

The study consisted of 1473 of normal BMI (18.5-24.9), 3081 overweight women (25-29.9 BMI), 4196 obese women (30-39.9 BMI), and 1446 of morbidly obese women (BMI greater than 40). Of all patients 1119 women (11%) developed preeclampsia, out of the women whom developed the condition eight hundred and one patients (8.6%) developed severe features. Since there has been evidence in previous studies that early-onset pre-eclampsia and late-onset pre-eclampsia could be triggered by different pathogenesis, the cases were separated by the incidence during early onset (339 women) and late onset (542 women). For the early-onset pre-eclampsia no relation between obese and overweight BMI and risk of pre-eclampsia with severe features was noted, also when looking at the total cohort there was no significant trend. On the other hand, when looking only at the results of late-onset pre-eclampsia there was a trend that indicated BMI and severe symptoms are correlated. For late-onset pre-eclampsia with severe features there were 2.9% of normal BMI women, 4.5% of overweight women, 6.2% obese women, and 6.8% were morbidly obese women; these results support that there is a statistically significant relationship between BMI and the development of late-onset pre-eclampsia with severe features. This experiment shows the importance of having a healthy BMI at the time of conceiving and throughout pregnancy.

Although a real preventitive solution for pre-eclampsia does not exist, the condition is widely studied and several methods to prevent it have been tried such as dietary recommendations, cardiovascular drugs, antioxidants, and antithrombotic drugs (prevention of blood clots).

Under dietary recommendations a low salt diet is advise, fish oil supplementation, and calcium supplementation; these three factors were studied with several trials. A study performed by Steegers et al. suggested that no sufficient evidence was found to determine that a low salt diet will help in the prevention of pre-eclampsia. Also, a different study showed that prescribing a low sodium diet is not beneficial to reduce the rate of pre-eclampsia (Knuist et al.). Although many sources claim that fish oil reduce inflammatory-mediated vascular disease, a European study conducted by Olsen et al. where a comparison between fish oil and olive oil effects in pregnant woman at high risk of pre-eclampsia showed no significant difference in symptoms of hypertension or pre-eclampsia. A different study found that pregnant women who ingested large amounts of fish oil during early pregnancy actually contributed to the increase risk of hypertensive disorders therefore high supplementary fish oil during pregnancy is not a valid prevention factor for pre-eclampsia (Sibai et al). During a research, Belizan et al. studied calcium as a means to prevent pre-eclampsia, they found that calcium supplementations reduces maternal blood pressure and although the reason for this is unknown these scientist suggested that calcium influences parathyroid hormone release and intracellular calcium availability; but the United States Food and Drug Administration concluded that the relationship between calcium and decreased maternal blood pressure is inconsistent and inconclusive, and the amount of calcium to be given in calcium deficiency population for it to cause and effect would be fairly high.

Diuretics have also been studied in the prevention of pre-eclampsia as cardiovascular drugs, women given diuretics had a decreased occurrence of edema and hypertension but not of pre-eclampsia. Unfortunately, these studies did not have enough participants to determine a sure answer to whether or not diuretics do help in the prevention of pre-eclampsia (Sibai et al. 215).

There is evidence that increased free radical oxidants in plasma could be a reason to develop pre-eclampsia, this is why vitamin C and E as antioxidants have been studied since these naturally occurring vitamins help lower Low-Density Lipoprotein (LDL) oxidation and reduce both superoxide formation and cytokine production, unfortunately, in different studies the results could not be linked to benefits of using antioxidants as a means of pre-eclampsia prevention.

On the other hand low doses of Aspirin was used in studies as an antithrombotic agent, The Paris Collaborative Group developed 31 randomized trials with 32,217 women, and they found that the risk of developing pre-eclampsia was slightly reduced for those women who were given aspirin (Sibai et al. 217).

It is known that exercise is an effective way to lower high blood pressure in non-pregnant individuals, for this reason it has been study as a prevention and control of hypertension and pre-eclampsia during pregnancy. Two identical studies by the University of Oregon and University of Minnesota showed that exercise during pregnancy improves angiogenic balance, but it does not help to reduce hypertension in rats. Even though this experiment showed no difference in blood pressure, it did show improvement of angiogenic balance, and it is known that angiogenic imbalances lead to decreased vascular endothelial function and health, systematic oxidative stress, renal dysfunction, and high blood pressure (Banek C.).  It was determined that exercise before pregnancy and during pregnancy could help with reduce blood pressure; although molecular explanations for this is not known.

Conclusion

Pre-eclampsia and eclampsia have been affecting pregnant women for many years. Before pre-eclampsia was determined by symptoms of high blood pressure and high protein levels in urine, it was hard to draw the line between these two conditions, ending in women having seizures. Pre-eclampsia has earned the recognition of a mysterious disease, and the only “real” cure is the induced delivery of the child. To manage it doctors first look at the severity of the symptoms, then the fetal gestational stage, maternal and fetal status, presence of labor, and last they consider the wishes of the mother; all these play a factor at the decision of doctors. A lot of research and medical trials are still needed to understand more about this disease, but according to my research one of the best ways to prevent this condition is to start off by being healthy before getting pregnant, doing regular exercise before and during pregnancy, and maintaining a healthy BMI. Although a low salt diet, fish oil, and antioxidants did not prove to be effective, I would agree that maintaining a healthy diet will contribute not only to the prevention of pre-eclampsia but also to other conditions that could lead to this disease. More research is needed to understand the cause, cure, and prevention of pre-eclampsia.