**4. Clinical research in women pregnant with PE**

Pregnancy is a physiological condition inherent in almost all species and life; however, it is one of the lesser known states and a field of research that just begins to grow, because at the beginning of research with pregnant women, a series of events occurred that negatively marked research in this population.

Research is now making its way into the subject of pregnancy and its pathologies in order to have a better understanding of physiological processes and to reduce maternal-fetal morbidity and mortality. However, despite the intentions and efforts of researchers, little is known. In the context of PE, it has been possible to trace its origin to the inadequate invasion of the trophoblastic villi on the vascular bed of the uterine spiral arteries, little is known about the cause of this inadequate adaptation of the uteroplacental vascular system [8]. Moreover, we are in complete disbelief about why some women develop PE and others do not. There is no effective diagnostic test to predict who will have PE, the best biomarkers have poor predictive power, the best chance to achieve prevention so far arises from the combination of Doppler ultrasound with some of the serum markers, which have been implemented, nevertheless, only demonstrate efficacy once the first evident changes of PE are presented, when it is no longer possible to avoid the development of the disease [9]. A real opportunity for prevention of PE would arise from a marker that would allow us to know with great certainty, which women are at risk of having PE, even before the pregnancy is carried out. The best predictive tool we have are the risk factors that have been determined by both prospective and retrospective studies, but are only able to predict 30% of women who develop PE [9], there is even a larger group of the population that develops PE with no previous risk factors. On the other hand, from the group of women who develop PE, one part shows severe PE and another group develops eclampsia, and again it is not possible for the treating doctors to determine who and how they evolve to more serious stages.

**5. Current state of research about PE**

ity caused by this disease (**Figure 2**).

There are currently 236,008 clinical trials registered in clinicalTrials.gov, from which only 3% are focused on pregnancy, and among them 6.4% are about PE. Of all clinical trials dedicated to PE, 47.9% focus on strategies to improve treatment, 22.2% of the clinical trials aim to improve the diagnosis or its establishment in the early stages, and 16.7% aim to establish the utility of new biomarkers, for both diagnostic and monitoring. Finally, only 10.7% of the clinical trials registered until February 1, 2017 are focused on the prevention of PE (**Figure 1**). Another aspect that should be taken under consideration is that more than half of the clinical trials directed to PE are carried out in regions classified as first world such as Europe and North America, whereas research in the rest of the world only constitutes 40%, despite the fact that developing countries are the ones that bear the greatest burden of morbidity and mortal-

Clinical Trials in Pregnant Women with Preeclampsia http://dx.doi.org/10.5772/intechopen.70185 51

In our times, PE has a worldwide relevance and it has been increasing over the years. Clinical trials with the objective of reducing the morbidity and mortality of this pathology have also increased over time. The previous chart denotes some of the terminated trials registered in clinicaltrials.gov, many of which have certain limitations that we were able to observe (**Table 1**). In the study titled, "l-arginine and antioxidant vitamins during pregnancy to reduce preeclampsia", there is little coherence between the objective and the design of the study. Although

**Figure 1.** Clinical trials registered until February 1, 2017. Data from: clinicaltrials.gov.

In women with severe PE, who present it before fetal viability, maternal stabilization is recommended before interruption of pregnancy. Once treatment is established, close monitoring is required to identify the presence of serious complications of PE. Despite efforts to treat PE, treatment is symptom-based and focused on controlling blood pressure. In regard to the time of delivery, gestational age should transfer to the maximum possible. However, in severe PE, in addition to antihypertensive treatment, termination of pregnancy is recommended if it is greater than 34 weeks. If the pregnancy is less than 34 weeks and the mother and product are stable, the pregnancy should be continued with administration of corticosteroids. Currently, there are multiple criteria for better management of PE, but the only cure for PE is termination of pregnancy. This results in a difficult decision for the physician and the mother because of the psychological burden, and the social and economic morbidity [8].

The results of medical interventions have failed to significantly decrease the morbidity and mortality of PE. The main reason for this failure could be the multifactorial origin of pathogenic processes that lead to the development of PE. Therefore, the approach for management of patients with PE is preventing its late occurrence in pregnancy. The key to prevention of PE is knowledge of the factors that trigger pathophysiological processes that culminate in the presentation of the PE. However, efforts to understand the origin of these processes are still poorly or incompletely understood. There is a lack of knowledge because the approach to study this population may be unethical compared with diseases of nonpregnant women [10]. The multifactorial origin of PE and difficulty of carrying out an investigation in the early stages of pregnancy, because it can endanger the mother and fetus, have made research difficult. Understanding the developmental characteristics of the placenta in pregnancy at high risk for PE is essential for understanding the pathophysiology and for developing strategies of prevention [8].
