During pregnancy, a woman’s body makes more blood for the growing baby. Their body adjusts; the heart gets bigger and pumps faster and harder. In women with congenital heart defects, pregnancy may strain the heart and cause it not to work as well.
As the mother’s heart gets ready for giving birth, extra hormones are released that make the heart pump stronger. These hormones can also make the heartbeat abnormal or faster.
Also, the mother’s body prepares for giving birth by making it easier for their blood to clot. Some women with congenital heart disease get blood clots in the circulation more than others. Medications can help manage this.