Early toxicosis is a disease of pregnant women whose development is associated with the growth of gestational sac or its components; the condition is characterized by many signs. When the gestational sac or its components are removed, the disease discontinues, as a rule.
Early toxicosis develops in the first weeks of pregnancy; the signs subside after 12-13 weeks gestation, as a rule.
19.1. EPIDEMIOLOGY
Nausea and vomiting are the most common, unpleasant signs of the first trimester of pregnancy; however, not all pregnant women with these signs develop toxicosis. Nausea and vomiting in pregnancy are due to changes in the digestive system as the vagal effect increases, as well as the content of hCG and steroid hormones (Fig. 19.1).
The incidence rate of toxicosis is 2-3%; in 85-90% of pregnant women toxicosis presents as vomiting, but no more than 8-10% of them require treatment. Severe forms develop in 0.5% of patients.
Fig. 19.1. β-hCG concentration and nausea and vomiting of pregnancy
19.2. ICD-10 CODES
• O21 Excessive vomiting in pregnancy.
- O21.0 Mild hyperemesis gravidarum.
- O21.1 Hyperemesis gravidarum with metabolic disturbance.
- O21.2 Late vomiting of pregnancy.
- O21.8 Other vomiting complicating pregnancy.
- O21.9 Vomiting of pregnancy, unspecified.
19.3. HISTORICAL REVIEW
The term toxicosis was introduced in the early 20th century; it does not reflect the essence of abnormality nor agrees with present-day views of its causes. Some authors attributed the cause to toxins and «abnormal» metabolism in the pregnant woman's body. Other authors stated that toxins are formed in the placenta or chorion whose fragments pass to maternal blood stream, degrade there and produce a toxic effect. Multiple attempts to isolate toxic substances in the body of a pregnant woman with toxicosis failed. However, the term «toxicosis» is still in use; it covers the whole range of disorders from nausea of pregnancy to jaundice of pregnancy.