**1. Introduction**

Preeclampsia (PE) is the leading cause of preterm birth by medical indication when associated with premature detachment of placenta normoinserta, and IUGR is associated with high perinatal morbidity and mortality and long-term sequelae. It has been described that standardization in the management of health services and the use of clinical practice guidelines is associated with a reduction in adverse outcomes, and a fundamental part of the management of severe PE includes a complete evaluation of the mother and the fetus. Despite the advances in medicine, the frequency of this syndrome has not changed, and globally its incidence ranges between 2 and 10% of pregnancies. The World Health Organization (WHO) estimates that the incidence of PE is seven times higher in developing than in developed countries (2.8–0.4%). In Mexico, it is estimated that PE is a major cause of maternal and perinatal morbidity and mortality. In Jalisco alone, maternal deaths increased to 57.14% from 2011 to 2014, placing this state in fourth place at the national level in terms of maternal deaths, during 2015 [1]. Because it is a heterogeneous associated idiopathic syndrome to endothelial damage, so far there is no effective treatment that reduces the morbidity and mortality of this pathological entity, so it is necessary to reinforce prevention. In this area, only the use of calcium supplements and acetylsalicylic acid (ASA) appears to be a recommendation, albeit with controversial results [1, 2].

resistance is reduced due to high flow and low resistance circuit in the uteroplacental circulation. In pregnancy, uterine blood flow significantly increases to allow perfusion of intervillous placental spaces and fetal development. The trophoblast invades the uterine spiral arteries; vascular smooth muscle cells are lost and replaced by the fibrinoid material, converting them into large dilated blood vessels allowing greater perfusion of the placenta [4]. These changes pose a challenge for the researcher as they make it very difficult to define not only the possible therapeutic results of an intervention, but also to adapt the intervention to these new changes that are not present in nonpregnant women. In a pathological condition such as preeclampsia, this may represent a greater challenge, because of restrictions on research in a physiological pregnancy, ignorance or doubts about the effects of the intervention on the organism, or pathological adaptations that may affect the intervention that is intended to be

Clinical Trials in Pregnant Women with Preeclampsia http://dx.doi.org/10.5772/intechopen.70185 47

The ethical complexity is established in the possibility that the intervention applied in key phases causes a teratogenic risk or that affects the adaptation of the product to extrauterine life, and more worrying, the possibility of long-term toxicity. This is why it is necessary that preclinical teratogenicity studies have been completed prior to the intervention in pregnant women. Also, it is recommended to start the new interventions after the 12th week of gestation, when the organogenesis is finished and finally, it is recommended to follow the fetus and newborn [5]. However, these special considerations do not seem to be sufficient, as there are currently two forms of research in the group of pregnant women: the first consists of interventions unrelated to pregnancy that may benefit only the mother [3]. It seems that the previous recommendations were formulated with this type of research, since the use of thalidomide has contemplated the possibility of developing drugs that may attenuate different discomforts during pregnancy. The clinical investigation currently has to verify that the pharmacological interventions do not cause damage to the product and not only benefit the mother. The second type of research concerns interventions that may potentially benefit the mother and her fetus [3]. This aspect is more related to the development of pharmacological interventions for pathologies in pregnancy, specifically speaking of preeclampsia, the treatments are not indicated at the same time for the mother and for the fetus. Betamimetics used to prevent preterm birth are not intended to treat the mother and may even complicate maternal health. In contrast, depending on the severity of hypertension, the drugs could have a toxic effect on the fetus. These two aspects should be considered when deciding to experiment with a new

When deciding that the study population is the group of pregnant women, the first ethical criteria that need to be reviewed are those aimed at the protection of the fetus. Generally, investigations of pregnant women involving an intervention or experimental procedure such as in PE cases, should not expose the embryo or fetus to a greater risk than the minimum, except when the use of the intervention or procedure is justified for saving the life of the mother. However, in addition to a deep and sufficient knowledge of the intervention that is proposed to apply, there is no strategy to evaluate during the course of research the side effects on the

performed are greater.

therapeutic product or scheme [5].

**3. Fetal well-being in the clinical trial**

The main problem of PE is threefold, the diagnostic difficulty, the complicated interrelationship of the pathophysiological processes, and the vulnerability of the maternal-fetal binomial to the therapeutic interventions.
