Obstetric and Neonatal Outcomes in Patients with Surgically Repaired Heart Disease.

BACKGROUND: Congenital and acquired heart disease complicate 1-4% of pregnancies in the United States. Beyond the risks of the underlying maternal congenital heart disease, cardiac surgery and its sequelae, such as surgical scarring resulting in higher rates of arrhythmias and implanted valves altering anticoagulation status, have potential implications that could affect gestation and delivery.

OBJECTIVE: To investigate whether history of maternal cardiac surgery is associated with adverse obstetrical or neonatal outcomes when compared to patients without a history of cardiac disease or surgery, considered "healthy controls".

STUDY DESIGN: This is a secondary analysis of retrospective cohort studies performed at a tertiary care facility in the United States comparing obstetrical outcomes in patients with a history of open cardiac surgery that delivered from January 2007 - December 2018 with healthy controls, that delivered from April 2020-July 2020. There were 74 pregnancies in 61 patients with a history of open cardiac surgery that were compared to pregnancies in healthy controls. Of the 74 pregnancies, 65 were successfully matched based on gestational age to controls at a 1:3 (case:control) ratio. The remainder of cases were matched at a 1:2 or 1:1 ratio; therefore, a total of 219 control pregnancies were included in the analysis. Our primary outcome was the incidence of hypertensive disorders of pregnancy, as well as cesarean section, in patients with a history of open cardiac surgery compared with healthy controls. Our secondary outcome was the incidence of low-birth-weight neonates in patients with a history of open cardiac surgery compared with healthy controls.

RESULTS: Patients with a history of cardiac surgery were not more likely to have any hypertensive disorder diagnosed than healthy controls. Patients with a history of cardiac surgery were more likely to have an operative delivery (p<0.0001) but equally likely to have a cesarean section (p=0.528) when compared with healthy controls. Birthweight was not statistically different of 2655 grams ± 808 grams in neonates born to patients with a history of cardiac surgery vs. 2844 grams ± 830 grams born to healthy controls (p=.092).

CONCLUSIONS: Patients with a history of cardiac surgery may not be at higher risk of hypertensive disorder diagnosis during pregnancy. Similarly, most patients with a history of cardiac surgery are also likely not at higher risk for cesarean section or low birthweight neonates.