Pregnant women with congenital heart defects (CHDs) have more comorbidities and more complications at delivery; a large new study using the National Inpatient Sample (NIS) data confirms. “Women with congenital heart disease are at a higher risk of a number of cardiovascular events and complications during pregnancy,” Dr. Lauren E. Schlichting of Brown University in Providence, Rhode Island, told Reuters Health by phone.
More and more women with CHD are having children, and they are known to at increased risk for adverse cardiovascular; obstetric and fetal events. However, they add, most studies have been small and done at clinics or hospitals. They looked at NIS data for 2008-2013 on more than 22 million deliveries; including 17,729 to women with CHD. Seventy percent had mild to moderate CHDs, 25% had isolated atrial septal defects and 5% had severe CHDs.
Women with CHD
Mean total hospital charges were $13,615 for women with CHD; compared to $10,985 for those without heart defects; hospital length of stay was 2.3 days with CHD and 1.8 days without CHD (both P<0.001). CHD patients were significantly more likely to have comorbidities, including pulmonary hypertension (PH) (adjusted odds ratio, 193.8); congestive heart failure (aOR, 49.1) and coronary artery disease (aOR, 31.7).
Adverse events including heart failure (aOR, 22.6), arrhythmias (aOR, 12.4), thromboembolic events (aOR, 2.4); pre-eclampsia (aOR, 1.5) and placenta previa (aOR, 1.5) also significantly more common in women with CHD. Women with CHD were also more likely to have a cesarean section, induced delivery, and operative vaginal delivery, although fetal distress occurred less frequently.
Risk of heart failure
Women with CHD and PH had an increased risk of heart failure compared to those without PH; their risks of hypertension in pregnancy, pre-eclampsia and preterm delivery also higher. They are also more likely to undergo a cesarean section. Comorbidities and adverse events not more frequent for women with severe CHDs.
“The limitation of our data set is it’s only a delivery record,” Dr. Schlichting said. “Our research would have been enriched if we had access to the patient medical history to know if they had a repaired defect or not; which could influence the occurrence of these adverse events.”
In an accompanying editorial, Dr. Ami B. Bhatt of Massachusetts General Hospital in Boston writes: “There are several key lessons from this research: maternal comorbidities are often predictable and, therefore, manageable if not preventable and their presence does not necessitate obstetric intervention. Nonetheless, obstetric care is an important mechanism for identifying individuals who have fallen out of cardiac care. Additionally, individuals with severe CHD require longitudinal planning that begins far before pregnancy is considered.”