Cardiovascular Surgeon Op.Dr.Orçun Ünal gave important information about the subject.
Here are these changes;
– Increase in blood volume: It is the most important change that occurs during pregnancy. Blood volume increases rapidly from the early period of pregnancy to the end of pregnancy, more rapidly until the 20th week. Since the liquid part of blood, which we call plasma, increases more than blood cells, it is possible to talk about ‘watering the blood.’ The increase in blood volume is aimed at protecting the mother from blood loss that may occur during childbirth.
– Increase in cardiac output: Cardiac output starts to increase from the 8th and 10th weeks of pregnancy in order to allow the increase in blood supply in the mother’s kidney, liver, lung, musculoskeletal system and uterus (uterus). An increase of 30-50% is seen in the heart’s stroke volume. As the pregnancy progresses, cardiac output increases while lying on your side and decreases when lying on your back. This is due to the fact that the uterus, which has grown while lying on its back, presses the main vein located just in front of the spine and reduces the returning blood flow to the heart.Therefore, especially in recent months, pregnant women are not recommended to lie on their back.The resting heart rate increases on average 10-20 / minute during pregnancy. Heart rate may increase more in multiple pregnancies. It is possible to see a decrease in heart rate while lying on your side.
– Blood pressure changes: Blood pressure decreases in the first trimester of pregnancy. (Trimester: The gestation period is divided into three periods as first, second and third (first, middle and last) trimesters) The tendency to decrease in blood pressure continues until the middle of the second trimester and returns to pre-pregnancy values in the last three months. Water and salt retention, especially in the last trimester of pregnancy, is a cause of fluid increase in the body.
–Heart Rhythm Disorders: Arrhythmia, triggering the infrastructure existing from childhood; As it may occur due to excessive stress, intense effort, fear and tension, women in particular face rhythm disorder mostly due to hormonal reasons. During pregnancy, some rhythm disorders may occur due to the stress and burden of pregnancy. Beta-blocking drugs are used in these arrhythmias. This group of drugs is safe considering the side effects of other drugs. Other antiarrhythmic drugs used in radical and incurable rhythm disorders are discontinued during pregnancy. These drugs may have to be replaced with other drugs that have less side effects. During pregnancy, especially bradycardia, that is, the situations where the heart works slowly is very important. Some heart rates that can be tolerated in normal life (45-50) negatively affect the feeding of the baby during pregnancy, and low heart rates pose a danger to the baby.
Expectant mothers with pre-pregnancy heart disease should be closely monitored during their pregnancy. Necessary precautions should be taken to eliminate the possible adverse effects of sudden changes that occur at the end of the pregnancy, especially during delivery, in which the cardiologists and obstetricians should work together.