Diagnosis of pregnancy and knowledge of normal findings associated with early pregnancy are common issues in the medical care of reproductive age women. Over 200 million pregnancies occur in the world each year . More than 6 million women are diagnosed with pregnancy each year in the United States, and millions more have sought diagnostic testing. Early diagnosis of pregnancy may prompt women to seek prenatal care earlier and take measures that can benefit the fetus, such as improving glucose control (in women with diabetes) or avoiding alcohol and potentially harmful drugs. Early diagnosis also provides the best opportunity for accurate estimation of gestational age.
The diagnosis of early pregnancy is based primarily upon laboratory assessment of the presence of human chorionic gonadotropin (hCG) in urine or blood (table 1). History and physical examination are not highly sensitive methods of diagnosis, but knowledge of the characteristic findings of a normal pregnancy can be helpful in alerting the clinician to the possibility of an abnormal pregnancy, such as ectopic pregnancy, or the presence of coexistent disorders.
PHYSIOLOGY OF NORMAL PREGNANCY
Most of the clinical findings associated with normal pregnancy can be attributed to end-organ effects of the hormonal changes associated with pregnancy. These pathophysiological changes are described in detail separately:
●(See "The skin, hair, nails, and mucous membranes during pregnancy".)
●(See "Maternal cardiovascular and hemodynamic adaptations to pregnancy".)