For women with congenital heart defects, having a baby can be risky

For years, the only thing standing between Candace Martinez and motherhood was her heart. She was born with a defect that a generation earlier would have led to death as an infant, but modern medicine – open-heart surgery at 5 weeks to swap two misconnected arteries – had saved her. At 18, she suffered from heart failure: her heart muscle could not pump enough blood to oxygenate her body. At 19, she had a pacemaker.

Martinez survived, but she always assumed that the life modern medicine had given her would not include having children. Pregnancy and childbirth have long been considered too difficult for women with congenital heart defects like hers.

No more. Recommendations adopted in January by the American Heart Association suggest that, with careful monitoring and management, many complex congenital heart defects should not be a barrier to pregnancy.

For Martinez, 33, of Bakersfield, Calif., the recommendations couldn’t have come soon enough. After spending the beginning of her pregnancy at Ronald Reagan UCLA Medical Center and the rest near the hospital, she gave birth to a baby girl on Valentine’s Day. The pregnancy wasn’t exactly easy: Martinez’s heart started beating abnormally at one point and the doctors gave her an electric shock to bring it back to normal. But her daughter is healthy and so is she.

“Where we used to think pregnancy was not possible or was prohibitively risky” for women with complex heart defects, said her UCLA cardiologist Jamil Aboulhosn, one of the authors. new AHA guidelines, “many of these women can actually tolerate a pregnancy, but these are still high-risk pregnancies” that should take place in settings with the proper infrastructure and practitioners who know how to care of these patients.

It’s easy to forget how risky pregnancy and childbirth are in general. Maternal mortality – historically one of the leading killers of women – remains a concern today, and cardiovascular disease is the main culprit. Among women who die during pregnancy or within a year, cardiovascular causes account for more than 4 in 10 deaths, according to the Centers for Disease Control and Prevention.

The heart has to work hard to grow a baby, explained Brian Koos, Martinez’s obstetrician at UCLA. Pregnancy increases a woman’s blood volume by 50% and her heart has to work 30-50% harder to pump enough oxygenated blood throughout the body. The mother’s heart rate increases during the second half of pregnancy and she is at higher risk of irregular heartbeats, called arrhythmias, and blood clots, Koos said.

Pregnancy in women with complex heart defects can be even more threatening. The new recommendations focus on complex congenital heart conditions, such as having a two-outlet ventricle, having extra or missing or transposed arteries — as Martinez did — or having a single ventricle. An estimated 10,000 babies are born in the United States with these defects each year, and more than 117,000 adults live with them.

“Women who have impaired heart function don’t have the heart reserve to meet these demands,” Koos said. But women have always had the choice to conceive, and “motherhood is a very strong force,” Koos added.

Until the 1960s, less than 10% of infants with complex congenital heart disease survived into adulthood, Aboulhosn said. But advances in heart surgery in the 1960s and 1970s dramatically prolonged the survival of these children. Surgeries such as the atrial switch, which Martinez had to correct the flow of oxygenated blood through his heart, and the Fontan procedure, which redirects blood to the pulmonary artery in those with a weak or absent right ventricle, are have become more common. In the 1980s, they were the standard of care for complex heart defects. In the 1990s, an arterial switch replaced the atrial switch, with apparently better results. (See box.)

A 2013 study found that more than three-quarters of infants born between 1979 and 2005 with complex congenital heart defects survived past their first birthday.

“Today, there are practically no more [heart] defect that cannot have some form of surgery performed from the time of birth,” said Mary Canobbio, a cardiology nurse at UCLA and chair of the group that wrote the AHA recommendations.

More than 90 percent of these children are now reaching adulthood, which has led to uncharted territory: the care of adults with complex congenital heart disease.

“Doctors were reporting the results of these surgeries in the ’80s, but no one was talking about pregnancy,” Canobbio said. Pregnancy was discouraged in these women, but some still conceived, requiring medical professionals to learn how to care for them.

“We have shown that yes, they can get pregnant. The next question was ‘Should they get pregnant?’ and that’s the problem that has really plagued cardiologists,” Canobbio said. The debate continues today, particularly regarding women in areas without an adult heart center with congenital heart disease.

Although careful management of these pregnancies has led to better outcomes, this does not mean that all women with a complex congenital heart defect should conceive. A woman’s cardiologist considers her clinical history, medications, and results of stress tests, an EKG, echocardiogram, and other assessments to determine her risk.

The risk of getting pregnant remains too high for some, such as those with Eisenmenger syndrome, a condition involving pulmonary hypertension (high blood pressure in the lungs), reversed blood flow, and cyanosis, in which oxygenated blood and non-oxygenated mix. The overall maternal mortality rate in the United States is two deaths per 10,000 women, or 0.02%. In women with Eisenmenger, it’s 30 to 50 percent, and more than a quarter of their babies die.

Most women with congenital heart disease who die as a result of pregnancy had conditions considered too risky for them to attempt childbirth, Canobbio said.

“It’s critical that these patients receive counseling well before they become pregnant,” Canobbio said. “If we don’t get the issues under control before the pregnancy, we potentially have a disaster.”

After conception, a woman like Martinez needs the care of an obstetrician, a cardiologist, a specialized nurse and an anesthesiologist, a multidisciplinary team whose collaboration and communication are essential to her care. Heart failure is a major risk: the heart may simply not be able to keep up with the demands of pregnancy. Another is arrhythmias, both during and after pregnancy. Treatment may involve medication, insertion of a pacemaker, bed rest, or cardioversion, in which an electrical jolt resets the heartbeat.

Fetal risks also exist. Miscarriages occur more often in some of these women. More than a quarter of newborn babies have complications, such as being underweight, poor growth in the womb and respiratory distress at birth.

“The data shows that we can help you get through a pregnancy if you’re clinically stable at the time of conception,” Canobbio said. “What we don’t know is whether the burden of pregnancy will shorten the lifespan of the mother.”

But “that’s the risk you take,” said Erica Thomas, a 37-year-old woman from Costa Mesa, Calif., who was born with a single ventricle, an atrial septal defect (a type of hole in the heart) and a missing tricuspid valve. What saved her life was the Fontan procedure she underwent as a newborn.

“The majority of my younger years were all about survival,” Thomas said. “They didn’t expect me to live, and it was about being a guinea pig.” When she was 6, her parents moved the family from Colorado to Los Angeles because the high altitude was too risky for her. Today, she has a healthy 5-year-old daughter and 2-year-old son.

“My husband and I never thought we would be able to have our own biological children,” Thomas said. “We are just grateful to have had this opportunity.”

Before we got pregnant, “we asked Mary [Canobbio] lots of questions because I wasn’t sure I wanted to be a guinea pig when I bring another life in there. But knowing that there were other people who came before me really helped us make our decision.

In her first pregnancy, Thomas’ water broke at 35 weeks, five weeks before a planned induction, and she suffered from complicated swelling and postpartum pain. In her second pregnancy, her water broke at 23 weeks, requiring hospitalization in hopes of making her pregnancy last another 10 weeks.

She succeeded, but her son was still premature, as are up to 65% of the children of these women. That’s why many women like her stay in the hospital or hotel near an adult congenital heart disease center for weeks before their induction date. This strategy paid off for Martinez when his daughter arrived early.

“I was able to hold her in my arms immediately, and it was amazing,” said Martinez, who just experienced her first Mother’s Day as a mother. “She was so small, and it melts your heart.”