Effect Study of Physiological changes of a Pregnant Woman

Abstract

Understating these changes and their profound impact on the pharmacokinetic properties of drugs in pregnancy isessential to optimize maternal and fetal health. During normal pregnancy, the renin–angiotensin system (RAS) plays avitally important role in salt balance and subsequent well-being of mother and fetus. In this balance, one must consider notonly the classical renal RAS but also that of the uteroplacental unit, where both maternal and fetal tissues contribute to thesignaling cascade. Many studies have shown that in normal pregnancy there is an increase in almost all of the componentsof the RAS. In derangements of pregnancy this delicate equilibrium can become unbalanced. Preeclampsia is one suchcase. It is a disorder of pregnancy characterized by hypertension, proteinuria and placental abnormalities associated withshallow trophoblast invasion and impaired spiral artery remodeling. Changes in the cardiovascular system in pregnancyare profound and begin early in pregnancy, such that by eight weeks’ gestation, the cardiac output has already increasedby 20%. The primary event is probably peripheral vasodilatation. This is mediated by endothelium-dependent factors,including nitric oxide synthesis, upregulated by oestradiol and possibly vasodilatory prostaglandins (PGI2). There is asignificant increase in oxygen demand during normal pregnancy. This is due to a 15% increase in the metabolic rate anda 20% increased consumption of oxygen.