Fetal Heart Development

Angela Thomas from Englewood Cliffs, N.J., remembers that feeling all too well. Last year she gave birth to her daughter, Maia, knowing that her daughter had a serious heart problem.

Hearing your baby’s heart for the first time is a never-to-be-forgotten prenatal experience.

“The problem was detected at the 5-month ultrasound check,” Thomas says. “Needless to say, we went through a tailspin especially where doctors mentioned the termination word. Something kept telling me not to terminate and I was vigilant for the remaining months with meditation and outstanding medical care. It was surreal but with faith and wonderful guidance [at] Columbia Medical University, Maia is doing incredible.”

Maia was born with a hole in the heart, and she had to have one of her valves detached and re-routed. Thomson’s vigilance and care was rewarded. After Maia was delivered, she went right into a very successful surgery.

Pregnancy and a Mother’s Heart

Dr. Curtis Rimmerman, a staff cardiologist at the Cleveland Clinic in Cleveland, Ohio, says that pregnancy results in a number of physiologic changes, including the heart.

“First and foremost, as the pregnancy proceeds, the vascular space and blood volume increases significantly,” he says. “The mother’s cardiac output increases to satisfy the increased placental blood flow that delivers oxygen-rich blood and nutrients to the developing baby.”

To meet this increased cardiac demand, the pregnant mother’s resting heart rate is increased. In addition, the amount of blood that is ejected from the heart with each heartbeat called the stroke volume is also increased.

“It is this combination of elevated heart rate and increased stroke volume that increases forward cardiac output and satisfies the nutritional needs of both the pregnant mother and her child,” Dr. Rimmerman says.

Normal Changes

According to Dr. Rimmerman, because blood flow is increased during pregnancy, cardiac murmurs typically develop. This is a normal phenomenon in the overwhelming majority of patients and simply reflects the heightened blood flow within the heart. This doesn’t represent a structural abnormality such as an abnormal heart valve.

“In the normal situation, expected murmurs are termed functional murmurs,” Dr. Rimmerman says. “It is important that both the physician and the pregnant mother not get alarmed should a soft functional or innocent heart murmur develop.”