However, apart from the impact of drugs on the fetus and there are others:

Suction drugs in pregnant women is changing: from the fact that the reduced tone of the digestive tract and, therefore, lipophilic drugs is longer in the lumen intestine, they are absorbed more strongly. In contrast, during pregnancy, secretion gastric juice is reduced, hence hydrophilic drugs are poorly dissolve and be absorbed. In applying rectal forms of drugs absorption is also reduced due to the fact that the enlarged uterus presses on the veins pelvis and the outflow of blood from the rectum is slow. However, inhalation method of introducing drugs to the rate of absorption may increase. This is that in pregnant women, generally, increases breathing capacity of lungs and blood flow in the vessels of the lungs and increases gas exchange.

Distribution drugs through the body of a pregnant woman, too changes. As a rule increases the amount of circulating plasma (30-40%) and up 5.8 liter increases the volume of extracellular fluid. The increase in plasma volume leads to reduce the therapeutic effect of the drug because of its "dilution". Because increasing the number of fat cells they will accumulate more lipophilic drugs, which in turn can demonstrate to the accumulation their toxic properties. Due to the fact that in the beginning of the 2 nd trimester falls albumin in plasma, the number of related drugs reduce and have more free fractions of drug that can lead to toxicity.