: Normal trophoblast growth is one of the more important stages of early pregnancy that has a deciding factor on its later development and normal outcome. Identifying pregnant women who have a high risk of complications connected to hypertension during pregnancy is currently one of the most important tasks of perinatal medicine. Abnormal placentation is related not only to the appearance of preeclampsia, but also to many other complications, such as premature placental abruption, intrauterine fetal demise, and intrauterine growth restriction. Preeclampsia and eclampsia are one of the major causes of maternal morbidity and mortality and appear in about 5% of all pregnancies. Clinical symptoms are a far-removed consequence of abnormal placentation. When they become visible, it is definitely too late for preventive action, and there is essentially no effective treatment. New research data suggests that a chance of prophylactic intervention might exist as early as in the first trimester of the pregnancy. One of the clinically documented possibilities is to apply low doses of acetylsalicylic acid before the 16th week of gestation. Despite the great importance of the placenta in the physiology of pregnancy, not much attention has been paid to the way it functions. This paper reviews selected biochemical and biophysical markers which are, or could be, used in clinical practice in the future.