Pregnancy despite a congenital heart defect? Until now, doctors often advised against this. The health risks for mother and child seemed too high. Now a new study gives the all-clear in part.

"The key finding is that many women who have a congenital heart defect can safely survive pregnancy and also birth," says Astrid Lammers, lead author of the study. "However, this should not hide the risks. According to the study results, children of mothers with a congenital heart defect are six times more likely to be affected by a malformation of the organ than the children of heart-healthy mothers," says the specialist in pediatric cardiology at the ACHD Center of Münster University Hospital.

World's Largest Study of Pregnancies with CHD

Based on anonymized data from Barmer Health Insurance, the researchers were able to track a total of 7,512 pregnancies in 4,015 women with congenital heart defects (CHD) and evaluate the corresponding medical factors.

Although the results clearly showed that mothers with congenital heart defects and their babies had a comparatively higher incidence of health complications than the control group of 6,502 heart-healthy women with a total of 11,225 followed-up pregnancies. "Basically, however, the women with congenital heart defects and their babies managed pregnancy and birth well, with no deaths in this group," Astrid Lammers notes.

It is very encouraging to see that so many patients with congenital heart defects can give birth to healthy children, she adds. The study helps doctors and patients to better assess the risks of pregnancy and the possible complications and problems of childbirth.

Impressive Evidence of Medical Progress

From the researchers' point of view, the result of the study is also part of a success story in terms of medical standards in Western industrialized countries. "When you consider that overall one in a hundred children is born with a congenital heart defect, this is impressive evidence of medical progress. Just a few decades ago, many children with congenital heart defects would not even have reached adulthood, even in this country," recalls Ulrike Bauer, scientific director of the National Registry and the Competence Network for Congenital Heart Defects.

Today, close-meshed care by ACHD specialists as well as the further development of neonatal intensive care and techniques mean that a large part of the problems observed in the study can be overcome with medical support. "Nonetheless, a thorough risk assessment by ACHD specialists should be performed urgently for anyone wishing to have a child."

Increased Risks for Mother and Child with CHD

According to the study, complications for mothers with congenital heart defects were relatively low overall. Nevertheless, this group showed an increased rate of stroke compared to women without congenital heart defects, at 1.13 percent versus 0.17 percent. Mothers with CHD also showed a higher risk of heart failure at 0.84 percent versus 0.03 percent. Similarly, there was a higher rate of cardiac arrhythmias (0.82 percent versus 0.12 percent). Deliveries by cesarean section were slightly more common among women with congenital heart defects, at 40.5 percent versus 31.5 percent among heart-healthy women.

Fetuses of expectant mothers with CHD had a slightly increased risk of prenatal mortality (1.4 percent versus 0.4 percent). The rate of infants who died in the first month of life was also elevated at 0.83 percent, compared with 0.22 percent in the heart-healthy control group. Newborns of mothers with CHD were also more likely to have low (1,000 to 2,499 grams) or extremely low birth weight (less than 1,000 grams).

Congenital Heart Defects Can be Inherited

Preterm birth, major visible anomalies, Down syndrome, or other genetic syndromes were slightly more common in CHD patients. Temporary mechanical ventilation of the newborns was also required more often in this group. Women with CHD are about six times more likely to have a child with a congenital heart defect themselves than women without CHD.

In addition, six percent of children of CHD patients required heart surgery with heart-lung machine support by the age of six, compared to 0.4 percent of heart-healthy mothers. "Children of mothers with CHD are affected to a higher extent by serious heart defects that need to be corrected early in life by open-heart surgery," classifies Astrid Lammers.

Expert Medical Support is Essential

Based on the results, the researchers were able to prove that the severity of the mother's heart defect and secondary diseases such as high blood pressure or heart failure, as well as blood-thinning treatment with anticoagulants in the year before pregnancy, but also previous fertility treatment, were associated with an accumulation of medical problems in newborns.

"It is therefore absolutely essential that expectant mothers with a congenital heart defect are cared for by an ACHD cardiology outpatient clinic that specializes in the follow-up treatment of congenital heart defects," emphasizes Astrid Lammers. She also says that pregnancy is not recommended for all congenital heart defects, as certain maternal heart defects are still associated with a very high complication rate for mothers.

Early Counseling with Existing Desire to Have Children

In the view of the researchers, this makes it all the more important for AHF patients who wish to have children to receive early counseling from their treating physician. Topics such as pregnancy and family planning should be addressed in good time, for example in order to be able to identify medications that pose a potential risk during pregnancy in advance and to change the drug treatment accordingly.

"Comprehensive expert support for this group of patients during pregnancy, birth and also after delivery by gynecologists, perinatal physicians, obstetricians and pediatricians is of outstanding importance for mother-child health, and accompanying close monitoring by specialized cardiologists is absolutely recommended," summarizes Astrid Lammers.