Meeting News

Physiological aspects of maternal cardiac disease must be understood to avoid complications

NASHVILLE, Tenn. – Managing maternal cardiac disease requires recognizing the physiological changes that affect cardiovascular health during pregnancy, a speaker at the American College of Obstetricians and Gynecologists said.

“A lot of people get very intimidated by maternal cardiac disease. ... But if you understand the physiology changes that occur during pregnancy, you will understand what most of the issues are,” David E. Abel, MD, an assistant clinical professor at the University of California, San Francisco, told attendees.

The CARPREG, ZAHARA and Modified WHO risk assessment algorithms are useful for understanding the physiological changes that can occur during pregnancy, which include:

  • an increase in cardiac output of 30% to 50% that peaks at 32 weeks gestation, with 75% of the increase taking place by the end of the first trimester and with most of the increase from stroke volume;
  • a decrease in systemic vascular resistance of about 20% that is responsible for most of the BP reduction and the circulating volume increase;
  • hypercoagulability, which increases the risk for venous thromboembolism by four- to fivefold, particularly in those with mechanical heart valves;
  • an increase in intravascular volume of about 50% with the maximum of this increase occurring at 32 weeks; and
  • a postpartum “autotransfusion” that builds on the 60% to 80% increase in maternal cardiac output after vaginal delivery.

Not all pregnant women with cardiac disease will experience every one of those physiological changes, he said.

Mothers with maternal cardiac disease are at increased risk for arrhythmias, sudden cardiac death, pulmonary edema, heart failure, stroke and infection, and the baby is at increased risk for spontaneous abortion, preterm delivery, recurrent heart disease, being small for their gestational age, perinatal mortality, respiratory distress syndrome, intraventricular hemorrhage and neonatal death, according to Abel.

Identifying patients at risk, even when asymptomatic, is critical for managing patients’ heart health, Abel said. ACOG noted the significant level of preventable mortality related to pregnancy, in the pre-, peri- and postpartum periods.

“You are the gatekeeper. Be liberal with your maternal-fetal medicine and cardiology pregnancy consultations, especially for those that may seem fine and especially for those who had been seeing a cardiologist and fell off the radar. ... You are the ones that can identify patients that need help prior to conception, whether it’s cardiology, maternal-fetal medicine or both, and that’s very important.” – by Janel Miller

Reference: Abel DE. “Maternal cardiac disease during pregnancy made simple.” Presented at: American College of Obstetricians and Gynecologists Annual Clinical and Scientific Meeting; May 3-6, 2019; Nashville, Tenn.

Also: MacDorman MF, et al. Obstet Gynecol. 2016;doi:10.1097/AOG.0000000000001556.

Disclosures: Abel reports no relevant financial disclosures.

NASHVILLE, Tenn. – Managing maternal cardiac disease requires recognizing the physiological changes that affect cardiovascular health during pregnancy, a speaker at the American College of Obstetricians and Gynecologists said.

“A lot of people get very intimidated by maternal cardiac disease. ... But if you understand the physiology changes that occur during pregnancy, you will understand what most of the issues are,” David E. Abel, MD, an assistant clinical professor at the University of California, San Francisco, told attendees.

The CARPREG, ZAHARA and Modified WHO risk assessment algorithms are useful for understanding the physiological changes that can occur during pregnancy, which include:

  • an increase in cardiac output of 30% to 50% that peaks at 32 weeks gestation, with 75% of the increase taking place by the end of the first trimester and with most of the increase from stroke volume;
  • a decrease in systemic vascular resistance of about 20% that is responsible for most of the BP reduction and the circulating volume increase;
  • hypercoagulability, which increases the risk for venous thromboembolism by four- to fivefold, particularly in those with mechanical heart valves;
  • an increase in intravascular volume of about 50% with the maximum of this increase occurring at 32 weeks; and
  • a postpartum “autotransfusion” that builds on the 60% to 80% increase in maternal cardiac output after vaginal delivery.

Not all pregnant women with cardiac disease will experience every one of those physiological changes, he said.

Mothers with maternal cardiac disease are at increased risk for arrhythmias, sudden cardiac death, pulmonary edema, heart failure, stroke and infection, and the baby is at increased risk for spontaneous abortion, preterm delivery, recurrent heart disease, being small for their gestational age, perinatal mortality, respiratory distress syndrome, intraventricular hemorrhage and neonatal death, according to Abel.

Identifying patients at risk, even when asymptomatic, is critical for managing patients’ heart health, Abel said. ACOG noted the significant level of preventable mortality related to pregnancy, in the pre-, peri- and postpartum periods.

“You are the gatekeeper. Be liberal with your maternal-fetal medicine and cardiology pregnancy consultations, especially for those that may seem fine and especially for those who had been seeing a cardiologist and fell off the radar. ... You are the ones that can identify patients that need help prior to conception, whether it’s cardiology, maternal-fetal medicine or both, and that’s very important.” – by Janel Miller

Reference: Abel DE. “Maternal cardiac disease during pregnancy made simple.” Presented at: American College of Obstetricians and Gynecologists Annual Clinical and Scientific Meeting; May 3-6, 2019; Nashville, Tenn.

Also: MacDorman MF, et al. Obstet Gynecol. 2016;doi:10.1097/AOG.0000000000001556.

Disclosures: Abel reports no relevant financial disclosures.

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