3. Preexistent chronic disorders, often directly affecting pregnancy

The first two chapters describe the strategy in mammalian pregnancy in general and human pregnancy in particular, how to secure the survival of the species without compromising maternal health. The first chapter discusses the specific adaptive strategy that a pregnant woman utilizes to achieve this goal. She temporarily accommodates an immunologically different human being within her body and by supplying this new life with sufficient O₂, nutrients and disposing of its metabolic waste products, enables it to grow and mature, in line with its genetic potential. She does this in a setting, that allows her to shield the infant from external stress factors, such as excessive heat, – cold and – physical forces and, last but not least, she provides the infant with the means to safely exit the maternal body to the outer world at a suitable time. Yet, even seemingly-healthy women may develop common pregnancy complications, such as early pregnancy loss, placental syndromes, preterm birth and gestational diabetes. These complications are often superimposed on a preexistent, often latent defect in the maternal cardiovascular system (sect. 3.1), renal function (sect. 3.2), metabolism (sect. 3.3), certain liver functions (sect. 3.4), or the immune – (sect. 3.5) and clotting systems (sect. 3.6). Such a defect limits a woman’s capacity to adapt to pregnancy and therefore, predisposes her to one of these pregnancy complications. This chapter describes the course and outcome of pregnancy in women with a chronic disorder affecting one of these six maternal functions and also, whether pregnancy will alter the course of her underlying chronic disorder.